Mercury is not viewable through March as it never leaves the Sun’s glare, but on the 25th of March, it reaches its greatest elongation in the East, marking the moment before retracing its path towards the Sun.
In the early mornings of March, Venus graces the celestial canvas, initiating its celestial journey in the constellation of Capricornus (The Sea-Goat). Its luminous path takes it through the constellation of Aquarius (The Water Bearer), and positions it between the constellations of Cetus (The Sea Monster), and Pisces (The Fish). Notably, on the 22nd of March, Venus shares the cosmic stage with Saturn, creating a mesmerizing spectacle visible through a single telescope eyepiece. Mars, a celestial companion to Venus at the start of March, commences its journey in the constellation of Capricornus, later finding its place in the constellation of Aquarius (The Water Bearer) by the month’s end. Meanwhile, Saturn, concealed by the Sun’s brilliance, reemerges in the evening sky towards the end of March, revealing its presence in the constellation of Aquarius.
As the sun sets, the evening sky unveils Jupiter‘s majestic presence, residing in the celestial expanse between the mythical figures of Cetus (The Sea Monster), and Aries (The Ram). At the beginning of March, Jupiter stands alone before embarking on a captivating cosmic convergence with Uranus, the first of the ice giants, situated between the constellations of Aries and Taurus (The Bull).
Planet | When It Rises Or Sets |
---|---|
Mercury | Lost to the Sun’s glare |
Venus | At the start of February, it’ll set at 04:08 am (AWST), and by the end of the month, it’ll set at 05:06 am (AWST) |
Mars | At the start of February, it’ll sets at 03:51 am (AWST), and by the end of the month, it’ll set at 03:44 am (AWST) |
Jupiter | At the start of February, it’ll set at 09:39 pm (AWST), and by the end of the month, it’ll set at 07:59 pm (AWST) |
Saturn | At the end of the month, it’ll rise around 04:20 am (AWST) |
Uranus | At the start of February, it’ll set at 10:02 pm (AWST), and by the end of the month, it’ll set at 08:08 pm (AWST) |
Neptune | Lost to the Sun’s glare |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
On Wednesday the 20th of March, The Northward Equinox occurs at 11:07 am (AWST), marking the beginning of astronomical Spring for the Northern Hemisphere, and the start of Autumn for the Southern Hemisphere. This is an exact moment when the Sun’s declination equals 0 as seen from the Earth. The two points where the ecliptic or the imaginary path the Sun seem to trace out along the celestial sphere meets the celestial equator are known as the equinoctial points.
The Equinox (literally meaning ‘equal nights’ in Latin) means that night and day are nearly equal worldwide, and that the Sun rises due east of an observer on the equinox and sets due west. The term Equilux is sometimes used to discern the difference between the true Equinox and the point when sunlight length equals the length of the night. Several factors play a role in this, including the time it takes the physical diameter of the Sun to clear the horizon, atmospheric refraction, and the observer’s true position in their respective time zone. The Equilux occurs within a few days of either Equinox.
On March 25th, 2024, a penumbral lunar eclipse will occur. This type of lunar eclipse occurs when the Moon passes through the Earth’s outer shadow, known as the “penumbra” (From the Latin paene ‘almost, nearly’). During this event, the Moon will appear slightly darker than usual, as it will only be partially covered by the penumbra.
This penumbral lunar eclipse unfortunately, will not be visible from Western Australia, but it will be visible for much of Europe, North/East Asia, Much of Australia, Much of Africa, North America, South America, Pacific, Atlantic, Arctic, Antarctica. A penumbral lunar eclipse is not as spectacular as a partial or a total lunar eclipse, but it still offers a unique opportunity to witness a rare astronomical event. Skywatchers will be able to see the subtle changes in the Moon’s brightness and colour as it passes through the penumbra. However, these changes will be quite subtle and may be difficult to discern without careful observation.
To observe the penumbral lunar eclipse, no special equipment is required. The eclipse will be visible to the naked eye from most locations, weather permitting. It is best to find a location with an unobstructed view of the Moon, away from any bright city lights that may interfere with visibility. With a little patience and a clear sky, skywatchers will be able to witness the beauty of the universe in action.
Event | UTC Time | Time in Sydney* |
---|---|---|
Penumbral Eclipse begins | 25th of March at 04:53:16 am | Below horizon |
Maximum Eclipse | 25th of March at 07:12:51 am | 25th of March at 07:03:51 am |
Penumbral Eclipse ends | 25th of March at 09:32:27 am | 6th of March at 08:32:27 am |
The Christmas Tree Cluster (NGC 2264) is a young open cluster located in the constellation Monoceros (The Unicorn). It’s part of the NGC 2264 region, along with the Cone Nebula and the Fox Fur Nebula. The cluster is located 2,700 light-years away from Earth and about 30 light-years across. The stars in the cluster were formed very recently from the surrounding molecular cloud. The cluster contains more than 600 stars that are 1 to 4 million years old.
The Christmas Tree Cluster is visible to the naked eye in good conditions and appears quite striking in binoculars. The Christmas tree shape can be seen in small telescopes at low power. The cluster can be found using the brightest stars of Orion and following a line drawn from Bellatrix to Betelgeuse to the east and a little bit north. The Christmas Tree Cluster is named for its triangular shape, formed by very young stars, that looks like a tree in visible light. It is in the northern part of NGC 2264, just above the Cone Nebula. The Christmas Tree Cluster was discovered by William Herschel on January 18, 1784.
The Beehive Cluster (M44) is an open cluster of faint stars in the constellation of Cancer, and it’s also known as Praesepe (Latin for manger). The cluster is not quite bright enough to clearly be seen as stars but more like a ‘cloud’. It’s easily visible to the naked eye and has been known since prehistoric times. Since the Greeks in ~3 centuries BC, it has been described as a small cloud or nebula and is the origin of the term as no other naked eye object had a similar appearance.
Its true nature was not shown until Galileo used the first astronomical telescope in 1609 to discover that it was in fact a collection of about 40 stars. We now know of 200 core stars, but there could be possibly up to 1000 stars in an extended area of nearly 3 Moon diameters. The cluster is 15 light-years in diameter, and it is 550 light-years away from Earth. The cluster contains a high proportion of variable stars of age 500-700 million years, this age of the cluster and its proper motion also coincide with those of the Hyades cluster in the constellation of Taurus, which suggests they may share similar origins.
The Ghost of Jupiter Nebula (NGC 3242) is a planetary nebula with a blueish-green tinge in the constellation of Hydra (The Water Snake) and it’s located 1,400 light-years away from Earth while being 0.3 light-years across. It’s one of the brightest planetary nebulae, however, it’s less than 1 arc minute in size and so it needs a high magnification and a large aperture telescope (16″ or more) to show its structure well. A planetary nebula is an emission nebula. However, rather than being a star formation area like the Orion Nebula (M42), it’s part of the late lifecycle of a star that has blown off a shell of material in a nova-style explosion. This shell of gas is irradiated by ultraviolet radiation from the remaining white dwarf and results in the emission nebulae from the shell of gases that is expanding from the star. This will also be the end result for our Sun at the end of its life.
The central star of the Ghost of Jupiter is in a triple-star system with a close brown dwarf and a more distant sun-like star in a 4000-year orbit around the other two. Planetary nebulae are generally spherical objects and relatively small in size, which is why they look like planetary discs in small telescopes. They are generally very short-lived phenomena of a few tens of thousands of years which then fade and become more tenuous as they recede from their source star. The Ghost of Jupiter Nebula happens to have a similar angular diameter to hence the ‘Jupiter’ part of its name first coined by Admiral William Smyth in 1837. Also known as the Eye Nebula, it was discovered by William Herschel in 1785.
Centaurus A (NGC 5128) is an elliptical galaxy that we see edge-on. The galaxy is the fifth brightest galaxy in the sky and one of the closest radio galaxies to Earth. It’s between 10 to 16 million light-years away from us and it can be found in the Centaurus constellation. The galaxy itself has a diameter of 60,000 light-years making it 40% smaller than our galaxy and at its centre, it has a supermassive black hole with a mass of 55 million suns. It was discovered in 1826 by Scottish astronomer James Dunlop from Parramatta, in New South Wales.
It’s a starburst galaxy meaning that it is undergoing a period of intense star formation compared to an average galaxy. Studies have confirmed that this high rate of star birth is caused by a collision between itself and a smaller spiral galaxy. The bright central bulge and the dark dust lane can be easily viewed using an amateur telescope however a larger telescope is required to view greater detail and contrast. Centaurus A is an extremely bright radio object, X-rays in particular. The central supermassive black hole is the source of this with two long radio jets extending well beyond the visual bounds of the galaxy.
In the celestial tapestry of February’s early morning sky. Mercury, Venus, and Mars gracefully traverse the vast constellation of Sagittarius (The Archer) before dawn. As the month progresses, their celestial journey leads them into the constellation Capricornus (The Sea-Goat). Venus and Mars, will grace the night sky throughout February and even be viewable in the same telescope eyepiece on the 23rd of February. However, Mercury, the elusive messenger, will retreat into the Sun’s radiant glow, bidding farewell to the stargazers two-thirds into the month.
In the evening night sky, Jupiter commands attention as it asserts its presence between the cosmic realms of Cetus (The Sea-Monster), and Aries (The Ram), throughout the entire month. Meanwhile, Saturn, the majestic ringed giant, graces the constellations of Aquarius (The Water Bearer), until it succumbs to the Sun’s brilliance halfway through February.
Uranus, the first of the ice giants, positions itself gracefully between the constellations of Aries, and Taurus (The Bull). Neptune, the azure wanderer, navigates the starry seas between the constellations of Pisces (The Fish), and Cetus. As the month draws to a close, Neptune, too, vanishes into the Sun’s radiant farewell.
Planet | When It Rises Or Sets |
---|---|
Mercury | From the middle of February, it’ll rise at 04:12 am (AWST), and by the end of the month, it’ll be lost to the Sun’s glare |
Venus | At the start of February, it’ll rise at 03:15 pm (AWST), and by the end of the month, it’ll set at 04:07 am (AWST) |
Mars | At the start of February, it’ll rise at 03:59 am (AWST), and by the end of the month, it’ll set at 3:52 pm (AWST) |
Jupiter | At the start of February, it’ll set at 11:21 pm (AWST), and by the end of the month, it’ll set at 098:42 pm (AWST) |
Saturn | At the start of February, it’ll set at 08:35 pm (AWST), and by the end of the month, it’ll be in the Sun’s glare |
Uranus | At the start of February, it’ll set at 11:53 pm (AWST), and by the end of the month, it’ll set at 10:06 pm (AWST) |
Neptune | At the start of February, it’ll set at 09:26 pm (AWST), and by the end of the month, it’ll be lost to the Sun’s glare |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Flame Nebula (NGC 2024) is an emission nebula in the constellation of Orion (The Hunter). It is about 900 to 1,500 light-years away and it’s 12 light-years across. The nebula can be located near the bright star Alnitak, the easternmost star in the Belt of Orion. Alnitak shines energetic ultraviolet light into the flame, and this knocks electrons away from the great clouds of hydrogen gas that reside there.
Much of the glow results when the electrons and ionized hydrogen recombine. Additional dark gas and dust lie in front of the bright part of the nebula, and this is what causes the dark system that appears in the centre of the glowing gas. The Flame Nebula is part of the Orion molecular cloud complex, a star-forming region that includes the famous Horsehead Nebula.
At the centre of the Flame Nebula, is an open cluster of newly formed stars, 86% of which have circumstellar disks. X-ray observations by the Chandra X-ray Observatory show several hundred young stars, out of an estimated population of 800 stars. X-ray and infrared images indicate that the youngest stars are concentrated near the centre of the cluster.
Messier 46 is an unusual open star cluster in that it appears to have a planetary nebula (NGC2438) embedded in it. The cluster is about 40 light-years across and located some 5,500 light-years away from Earth. There are an estimated 500 stars in the cluster, and most are around 300 million years old — very young for stars. While the planetary nebula appears to lie within M46, it is most likely unrelated to the cluster as it doesn’t share the cluster’s radial velocity. The star of this planetary nebula is a white dwarf with a surface temperature of about 74,700°C which makes it one of the hottest stars known to us.
Variable brightness and Colour, Eta Carinae is one of the most remarkable stars in the heavens. When we say “Eta Carinae” we refer to the star itself which for Perth is a circumpolar star (We see the star all year round) and not the nebula. Eta Carinae is 100 times the Sun’s mass and 4 million times brighter; this brightness has been unstable with the star being recorded over the past 300 years between magnitude -0.8 which is as bright as Canopus and +7.9. It’s a star that is sometimes in the news as it’s expected to become a supernova within the next 1 million years and will be a spectacular sight when it occurs, being visible by day and possibly bright enough to read by at night.
Eta Carinae is very likely a binary star with a smaller partner orbiting in a highly elliptical orbit of 5.5 years. The Carina Nebula (NGC 3372), which surrounds Eta Carinae, is a large, bright star-formation region that has produced several very massive stars including Eta Carinae. At around 260 light-years the Carina Nebula is around 7 times the size of the Great Orion Nebula, but due to its greater distance, it only spans twice the width. There are many O-type stars, young (~2 million years), hot and bright that energise the entire Carina nebulae.
The Pearl Cluster (NGC 3766) is a medium-sized open cluster in the constellation of Centaurus. Discovered by Nicholas Louis de Lacaille in 1752 where he spent two years at Table Bay, South Africa, the cluster is 5500 light-years away from Earth and 20 light-years across. The cluster is estimated to be around 15 million years old, forming from the large molecular cloud around the Carina region.
The area of the Pearl Cluster consists of around 140 stars and its super large and hot young stars have dispersed the nebulosity that surrounded the cluster. The cluster is not visible from 28° North (e.g., All of the UK and Europe north of the Mediterranean, most of the USA) and It’s circumpolar from Perth.
In January’s early morning sky, Mercury embarks on its celestial journey, transitioning from the constellation of Ophiuchus (The Serpent-Bearer) to Sagittarius (The Archer). On the 12th of the month, it reaches its greatest elongation in the West, marking the moment before retracing its path towards the Sun. Venus commences the month positioned between the constellations of Libra (The Scales) and Scorpius (The Scorpion). Throughout January, its radiant presence graces the night sky as it gracefully traverses Scorpius, and Ophiuchus, and ultimately culminates in the constellation of Sagittarius. Mars, commencing its celestial voyage between Ophiuchus and Sagittarius, steadily progresses through the month, concluding its cosmic dance in the expansive realm of Sagittarius.
In the evening night sky, Jupiter‘s celestial residence in January is nestled between the mythological figures of Cetus (The Sea-Monster), and Aries (The Ram). Meanwhile, Saturn makes its ethereal abode in the constellation of Aquarius (The Water Bearer).
Uranus, the distant ice giant, graces the celestial tapestry between Taurus (The Bull), and Aries, adding a touch of cosmic allure to the vast expanse. Neptune, the enigmatic ice giant, holds its celestial presence between the mythical constellations of Cetus and Pisces (The Fish), contributing to the captivating dance of the planets in the night sky throughout the month.
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of January, it’ll rise at 04:06 am (AWST), and by the end of the month, it’ll rise at 04:09 am (AWST) |
Venus | At the start of January, it’ll rise at 02:47 am (AWST), and by the end of the month, it’ll rise at 03:14 am (AWST) |
Mars | At the start of January, it’ll rise at 04:16 am (AWST), and by the end of the month, it’ll rise at 03:59 am (AWST) |
Jupiter | At the start of January, it’ll set at 01:22 am (AWST), and by the end of the month, it’ll set at 09:56 pm (AWST) |
Saturn | At the start of January, it’ll set at 10:28 pm (AWST), and by the end of the month, it’ll set at 08:39 pm (AWST) |
Uranus | At the start of January, it’ll set at 02:01 am (AWST), and by the end of the month, it’ll set at 11:48 pm (AWST) |
Neptune | At the start of January, it’ll set at 11:26 pm (AWST), and by the end of the month, it’ll set at 09:23 pm (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Earth will be at its closest point to the Sun (at Perihelion), about two weeks after the December Solstice at 08:38 am (AWST) on Wednesday the 3rd of January. The Earth will be 147,100,632 km away from the Sun that day and this occurs because the Earth’s orbit is elliptical. Approximately every 100,000 years, Earth’s orbital path changes from being nearly circular to elliptical. This is due to the gravitational influences of other planetary objects, particularly the Moon. The difference in the Earth’s orbital path from a perfect circle is known as its eccentricity. Also, the word Perihelion comes from ancient Greek, where Peri means close, and Helios means the Sun.
The Quadrantids are the first major shower of the year, and for those living in North America, much of Europe, and the majority of Asia you’ll be able to view them. Unfortunately, for us living in Australia and lower portions of South America and Africa, we won’t be able to view this shower as its radiant point (where the shower appears to be coming from) is in the Northern Hemisphere’s sky.
The Quadrantids are an annual shower that has one of the highest predicted hourly rates of all the major showers (40-120 meteors per hour to be more accurate) and it’s comparable to August’s Perseids for the Northern Hemisphere and December’s Geminids for the Southern Hemisphere. The object that causes the Quadrantids was tentatively identified back in 2003 by Peter Jenniskens as the minor planet 2003 EH1, which could be related to the comet C/1490 Y1 which was observed by Chinese, Japanese and Korean astronomers some 500 years ago.
The name comes from the former constellation Quadrans Muralis, which was created in 1795 by the French astronomer Jérôme Lalande and is now part of the Boötes Constellation. The meteor shower was first noticed in early January 1825, by Antonio Brucalassi in Italy who reported that “The atmosphere was traversed by a multitude of the luminous bodies known by the name of falling stars”, and that they appeared to radiate from the Quadrans Muralis Constellation. In 1839, Adolphe Quetelet of Brussels Observatory in Belgium and Edward C. Herrick who was in Connecticut independently suggested that the Quadrantids were an annual shower.
The meteor shower is active from the 28th of December through to the 12th of January with the peak being on the morning of Friday the 5th of January. If you live in the Northern Hemisphere and want to view the Quadrantids, you need to get up at around 2 am and look towards the Boötes Constellation which is the radiant point for the shower and not far from the Big Dipper. This year the Moon will be in its Full Moon phase, so people will have to deal with a lot of light pollution from it, which means you won’t see the fainter meteors.
The California Nebula (NGC 1499) is an emission nebula located in the constellation of Perseus. Its name is due to its resemblance to the outline of California in long-exposure photographs. Because of its very low surface brightness, it is extremely difficult to observe visually but it is a great Astrophotography target. It can be observed with a Hα filter or Hβ filter in a rich-field telescope under dark skies.
The nebule lies at about 1,000 light-years from Earth and is 60 light-years across. Its fluorescence is due to the excitation of the Hβ line in the nebula by the nearby star, Xi Persei (also known as Menkib). The California Nebula was discovered by Edward Emerson Barnard in 1884.
The Horsehead Nebula is a small dark nebula in the constellation Orion (The Hunter). The nebula is located just to the south of Alnitak, the easternmost star of Orion’s Belt, and is part of the much larger Orion molecular cloud complex. It appears within the southern region of the dense dust cloud known as Lynds 1630, along the edge of the much larger, active star-forming H II region called IC 434.
The Horsehead Nebula is approximately 1,375 light-years from Earth, and It is one of the most identifiable nebulae because it resembles a horse’s head. The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on a photographic plate taken at the Harvard College Observatory. Like the California nebula, it’s an astrophotography target as it appears very faint through a large telescope.
Winter Albireo (H3945 and SAO173349) is a visual double star in the constellation Canis Major and is named by Sir John Herschel (son of Sir William) and sometimes referred to as “Herschel’s Lovely Double” or the “Southern Albireo”.
This is not a binary system, but two stars in the same line of sight. The primary star HIP35210 is a Supergiant, ‘citrus orange’ in colour is much further away at 6523 light-years away compared to its companion star HIP35213 which is a ‘royal blue’ coloured star at 258 light-years away. Both stars are close double stars themselves with narrow separation, not visible in our modest telescopes.
The orange star is a Supergiant over twice the diameter of Betelgeuse with a diameter of 2.6 billion km. It would encompass the orbit of Jupiter if in place of our Sun. It is also ~365,000 times brighter than the sun because of its size, however, it has a much cooler surface temperature of ~3 300 K.
The secondary star is a much smaller main-sequence star at ~2.9 times the diameter of the sun and ~22 times the brightness with a much higher surface temperature of ~7 300K.
The Wishing Well Cluster (NGC 3532) is an open cluster in the constellation of Carina (The Keel). The cluster is located 1,600 light-years from Earth and is 24 light-years across. 677 stars are recognised as members of the cluster, and the cluster is rich in binary stars. It is estimated to be around 300 million years old and has ~ 2,000 solar masses.
To the naked eye, the cluster looks like an enhancement of the Milky Way, but by using a pair of binoculars or a telescope you’ll see five dozen or more stars. Its discovery is credited to 18th Century European explorer Louis de Lacaille who included it in his 1755 catalogue. The cluster is also known as the Firefly Party Cluster, and Black Arrow Cluster.
Jupiter, on the other hand, takes centre stage throughout the night, positioned between the constellations of Cetus (The Sea Monster), and Aries (The Ram). Saturn, another planetary gem, adorns the evening sky within the constellation of Aquarius (The Water Bearer), before setting later in the evening.
Uranus, the first of the Ice Giants, graces the night sky and can be spotted within the boundaries of Taurus (The Bull). Neptune, the most distant planet in our solar system, can be found nestled amid the constellations of Pisces (The Fish), and Cetus, offering a unique opportunity to spot this distant ice giant.
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of December, it’ll set at 08:48 pm (AWST), and by the end of the month, it’ll be in the Sun’s glare |
Venus | At the start of December, it’ll rises at 02:52 am (AWST), and by the end of the month, it’ll rises at 02:46 am (AWST) |
Mars | Lost in the Sun’s glare |
Jupiter | At the start of December, it’ll set at 03:29 am (AWST), and by the end of the month, it’ll set at 1:22 am (AWST) |
Saturn | At the start of December, it’ll set at 00:28 am (AWST), and by the end of the month, it’ll set at 10:32 pm (AWST) |
Uranus | At the start of December, it’ll set at 04:07 am (AWST), and by the end of the month, it’ll set at 02:05 am (AWST) |
Neptune | At the start of December, it’ll set at 1:32 am (AWST), and by the end of the month, it’ll set at 11:30 pm (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Geminids Meteor Shower is a celestial spectacle of paramount significance in the southern hemisphere. Mark your calendars for the night of December 14th to 15th, as this is when the Geminids will reach their zenith. The shower graces our skies for just over two weeks, spanning from December 4th to December 20th.
If you’re fortunate enough to find yourself in a dark location in Western Australia, you can expect to witness around 50 meteors per hour. The optimal viewing time is around 2:00 am (AWST). However, if your location lies closer to the equator, where the Gemini constellation (The Twins), reigns high in the sky, your meteor count may soar to an impressive 120 per hour. Moreover, you’ll be treated to an absence of lunar light pollution, thanks to a slender Waxing Crescent Moon that sets just prior to 10:00 pm (AWST).
The radiant point for this meteor shower appears to originate from the Gemini constellation, with the luminous streaks brought to life by minuscule dust particles and meteors hurtling into our atmosphere at breathtaking velocities, ultimately succumbing to the fiery embrace of friction. When you gaze at Gemini, don’t fixate solely on the constellation itself. Instead, explore about 30 to 45 degrees to the left or right of Gemini, as the meteors may not necessarily emerge directly from the constellation. However, if you trace these meteoric streaks back to their radiant point, it leads you right back to the heart of Gemini.
The Geminids were first discovered in 1862 and owe their existence to Earth’s journey through the remnants of the tail of asteroid 3200 Phaethon. This peculiar celestial body, classified as a rock comet, exhibits characteristics shared with comets, including a comet-like tail and surface jets. Gemini, the constellation from which the meteor shower takes its name, graces our night sky around 10:00 pm. For an optimal viewing experience, venture out after midnight when Gemini stands higher in the sky, as the shower intensifies with the passing hours of the night.
On the 22nd of December at 11:27 am (AWST), the December Solstice graces our calendar. This significant moment heralds the onset of astronomical summer for the southern hemisphere and the commencement of winter for the northern hemisphere. At this precise juncture, the Sun’s declination aligns perfectly at 23.5 degrees south, as perceived from our vantage point on Earth. The geographical parallel where the Sun directly hovers above during the December solstice is known as the Tropic of Capricorn. However, owing to the intricate celestial phenomenon of precession, the Sun now finds itself nestled within the astronomical constellation of Sagittarius in mid-December, marking a shift from historical references.
In the 21st century, the December solstice will grace our calendars on both the 21st and 22nd of December, until the year 2043, after which it will occasionally make its appearance on the 20th of December starting in 2080.
The December solstice signifies that the southern rotational pole of our Earth tilts towards the Sun, embarking on its lengthy, apparent journey northward, which will continue until June. This phenomenon, known as the Precession of the Equinoxes, unfolds over a vast expanse of time, taking approximately 26,000 years to complete a single cycle or “wobble.” To put it into perspective, within an average human lifespan of 72 years, the equinoctial points would have shifted by one degree, roughly equivalent to twice the diameter of a Full Moon. This enduring cosmic dance reminds us of the grandeur and scale of our ever-evolving celestial landscape.
The Pleiades, renowned as Messier 45, the Seven Sisters, and named Subaru in Japan, represent a youthful gem among open star clusters. Nestled within its celestial embrace are hundreds of stars, although only a select few grace the naked eye with their brilliance. This dazzling congregation of stars came into being as a collective entity around 100 million years ago within a cosmic nebula, and they now reside a considerable 425 light-years distant from our Solar System.
When we gaze upon the heavens, the Pleiades manifest themselves to the left of the Taurus Constellation, a mesmerising spectacle that truly comes to life when observed through the aid of binoculars or a wide-field telescope. Each radiant point in this celestial gathering whispers tales of cosmic birth and evolution, offering a glimpse into the mysteries of our vast and intricate universe.
The Orion Nebula, scientifically catalogued as M42, emerges as a captivating diffuse nebula in the celestial tapestry, positioned to the north of Orion’s Belt, particularly visible to observers in the southern hemisphere. Nestled within the boundaries of the illustrious Orion constellation (The Hunter), this luminous celestial masterpiece stands out as one of the most radiant nebulae in our night skies, making it an exquisite sight for the unaided eye.
This awe-inspiring cosmic creation, the Orion Nebula, resides at a distant 1,344 light-years away from our Solar System. Its vast expanse spans an estimated 24 light-years in diameter, a testament to the sheer scale of celestial wonders. Beyond its sheer beauty, the Orion Nebula has unveiled profound insights into the intricate process of stellar and planetary formation. It serves as a cosmic laboratory, where collapsing clouds of gas and dust give birth to new stars and planetary systems, shedding light on the very genesis of celestial bodies in the cosmos.
The Rosette Nebula, designated as NGC 2244, stands as a captivating HII region, situated near one extremity of an expansive giant molecular cloud, nestled within the cosmic confines of the Monoceros constellation (The Unicorn), within our Milky Way Galaxy. This celestial gem is adorned with an open cluster, where the remarkable birth of approximately 2,500 youthful stars takes place, originating from the very material that comprises the nebula itself. While the Rosette Nebula may prove elusive to the naked eye, even when observed through substantial telescopes, it truly shines as a splendid subject for astrophotography, with the accompanying star cluster offering a magnificent spectacle.
This captivating cluster and nebula duo are situated at an awe-inspiring distance of 5,000 light-years from our home planet, spanning an impressive diameter of around 130 light-years. The youthful vigour of the stars within the Rosette Nebula radiates energy that electrifies the nebula’s atoms, causing them to emit light akin to a radiant neon sign. This luminous phenomenon gives rise to the mesmerising emission nebula that graces our celestial canvas. The nebula’s substantial mass is estimated to be in the order of 10,000 solar masses, a testament to the cosmic forces at play within its boundaries. Notably, the focal point of ongoing star-forming activity resides within the dense molecular cloud situated to the southeast of the nebular bubble, where new stars continue to take shape.
Adding to its allure, the Rosette Nebula achieved a unique honour on April 16th, 2019, when the Oklahoma Legislature passed HB1292, designating it as the official state astronomical object of Oklahoma. Oklahoma Governor Kevin Stitt subsequently signed this designation into law on April 22nd, 2019, underscoring the nebula’s enduring fascination and cultural significance.
Tau Canis Majoris, officially designated as NGC 2362, stands as a mesmerising open cluster nestled within the constellation of Canis Major (The Dog). This captivating cosmic ensemble is located at an impressive distance of 5,000 light-years from our home planet and spans an expansive width of 10 light-years. Within its stellar embrace, one can find a gathering of approximately 100 to 150 stars, a youthful congregation with an age of merely 4 to 5 million years, making it remarkably young in cosmic terms.
The cluster’s historical journey began with its discovery by the keen eye of Giovanni Batista Hodierna before the year 1654. This celestial treasure was independently rediscovered by the eminent astronomer William Herschel in 1783, who aptly referred to it as a “beautiful cluster.” Further accolades for its celestial charm came from William Henry Smyth, who marvelled at its “beautiful appearance.” He noted the bright white star, Tau Canis Majoris, serving as its radiant centrepiece, adorned with a rich retinue of diminutive companions. These stars form a slightly elongated configuration, lending the cluster a distinctive and nearly vertical posture in our cosmic panorama.
Among this stellar cast, the luminary standout is Tau Canis Majoris itself, a beacon of luminosity that ranks among the most brilliant supergiants in our celestial repertoire. With an absolute magnitude of approximately -7, this star radiates with unparalleled brilliance. Amateur astronomers often affectionately refer to it as the ‘Mexican Jumping Star.’ This playful moniker arises from the intriguing optical illusion it presents when observed through telescopes. In this fascinating display, Tau Canis Majoris can seem to ‘jump around’ in relation to the other cluster stars when one gently taps the eyepiece. This captivating phenomenon is a testament to the stark contrast in brightness between this dazzling supergiant and its stellar companions, adding a touch of celestial magic to the observer’s experience.
In the celestial theatre of November, Mercury will once again grace the early evening sky, making its reappearance during the second week of the month amidst the constellation of Libra (The Scales). As November draws to a close, Mercury will journey onward, traversing the vast expanse of the Scorpius constellation (The Scorpion), before venturing into the constellation of Ophiuchus (The Serpent-Bearer).
At the onset of November, Venus will be a captivating sight in the pre-dawn hours, residing within the Leo constellation (The Lion). As the month progresses, Venus will gracefully transition into the neighbouring Virgo constellation (The Virgin). Regrettably, Mars will remain shrouded in the brilliant radiance of the Sun throughout November, rendering it invisible to those observing the night sky with the naked eye.
Jupiter, the regal giant of our solar system, will be a prominent fixture throughout the night, positioned between the constellations of Cetus (The Sea Monster), and Aries (The Ram). Meanwhile, Saturn will illuminate the evening sky within the realm of Aquarius (The Water Bearer), until it descends below the horizon halfway through the night. Jupiter will reach opposition on the nights of November 3rd and 4th, a celestial event when Earth positions itself directly between the Sun and Jupiter. This moment presents an excellent opportunity for observing Jupiter in all its glory.
For enthusiasts of the night sky, Uranus will make a continuous appearance throughout the night, taking residence in the constellation of Taurus (The Bull). Uranus will also reach opposition on the nights of November 13th and 14th, so it’s going to be the best time to see it. As a special treat for stargazers, Neptune will be nestled amid the constellations of Pisces (The Fish), and Cetus, offering a unique opportunity to spot this distant ice giant.
Planet | When It Rises Or Sets |
---|---|
Mercury | Second week of November, it’ll set at 07:41 pm (AWST), and by the end of the month, it’ll set at 08:46 pm (AWST) |
Venus | Halfway through November, it’ll rise at 03:13 am (AWST), and by the end of the month, it’ll rise at 02:53 am (AWST) |
Mars | Lost in the Sun’s glare |
Jupiter | At the start of November, it’s viewable throughout the night, and by the end of the month, it’ll set at 03:33 am (AWST) |
Saturn | At the start of November, it’ll set at 02:24 am (AWST), and by the end of the month, it’ll set at 00:32 am (AWST) |
Uranus | At the start of November, it’ll rise at 07:33 pm (AWST), and by the end of the month, it’ll set at 04:11 am (AWST) |
Neptune | At the start of November, it’ll set at 03:30 am (AWST), and by the end of the month, it’ll set at 01:35 am (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Northern Taurid Meteor Shower will grace the night skies from October 20th to December 10th, with its peak expected on the night of November 12th and 13th. The best viewing time is around 02:00 am (AWST), as the radiant point of the Northern Taurids will be at its zenith in the northern sky. In the year 2023, the Northern Taurids are projected to offer a display of approximately 5 meteors per hour, thanks to the Moon being in its New Moon phase, minimizing any potential light pollution.
The origin of the Northern Taurids is traced back to the asteroid 2004 TG10. This celestial traveller is an eccentric asteroid, classified as a near-Earth object and a potentially hazardous member of the Apollo group. It first caught the attention of astronomers when it was spotted by the Spacewatch survey on November 8, 2004. With a potential size exceeding one kilometre in diameter, asteroid 2004 TG10 is believed to be a fragment of Comet Encke, serving as the source not only for the Northern Taurids but also for the minor shower known as the June Beta Taurids.
The eagerly anticipated Leonids Meteor Shower will grace the night skies from November 6th to November 30th, with its peak spectacle expected on the night of November 18th and 19th. To catch the best view, set your alarm for approximately 03:00 am (AWST) just before the break of dawn. This timing is ideal because the radiant point of the Leonids resides within the Leo Constellation, and it ascends in the early morning hours. In 2023, the Leonids are forecasted to offer a display of approximately 10 meteors per hour, benefitting from the absence of moonlight, as the Moon will be in its Waxing Crescent phase and will have set before the meteor shower becomes visible.
The Leonid meteors make a dramatic entrance, hurtling towards Earth at a breathtaking speed of 71 km/s, often creating awe-inspiring fireballs. Their origin is traced back to Comet 55P/Tempel-Tuttle, and these meteors are known to deliver extraordinary outbursts approximately once every 33 years. Having surpassed the midpoint since the last notable outburst in 1998–1999, astronomers anticipate the next predicted ‘Leonid meteor storm’ to grace our skies in 2032–2033.
The historical significance of the Leonid Meteor Shower is deeply rooted in its past. The remarkable Leonid Storm of 1833 left an indelible mark on history, as it is believed to have played a role in the religious fundamentalist movements of the 1830s in the United States. On the morning of November 13th, 1833, residents along the eastern seaboard of the United States awoke to an astonishing sight, with meteors appearing to fill the sky like snowflakes in a winter storm. The sight was so extraordinary that it led many to flock to churches, believing that Judgment Day had arrived.
The Andromeda Galaxy (M31) stands as a magnificent spiral galaxy, located at a distance of roughly 2.5 million light-years from Earth. It holds the distinction of being the nearest major galaxy to our own Milky Way. Its name is derived from its location in the night sky within the constellation of Andromeda.
In 2006, groundbreaking observations conducted by the Spitzer Space Telescope unveiled a remarkable fact about the Andromeda Galaxy—it boasts an astounding population of approximately one trillion stars. This stellar abundance is more than double the estimated number of stars in our very own Milky Way Galaxy, which is believed to house between 200 to 400 billion stars. Spanning a colossal distance of around 220,000 light-years, the Andromeda Galaxy proudly claims the title of the largest galaxy within our Local Group.
However, what makes the Andromeda Galaxy even more intriguing is its cosmic fate. In a grand cosmic ballet that unfolds over the span of billions of years, the Milky Way and the Andromeda Galaxy are destined for a dramatic collision and merger. Approximately 4.5 billion years from now, these two colossal galaxies will engage in a celestial tango, ultimately converging to create either a massive elliptical galaxy or a sprawling, majestic disc galaxy. This extraordinary cosmic event is a testament to the ever-evolving nature of the universe.
Nestled within the southern constellation of Carina (The Keel), lies the captivating Southern Beehive Cluster, also known by its scientific designation, NGC 2516. This celestial gem goes by several monikers, including the Diamond Cluster and the Sprinter Cluster. Amateur astronomers affectionately dub it the Southern Beehive Cluster due to its striking resemblance to the Beehive Cluster (M44), a well-known cluster found in the constellation of Cancer, “The Crab.”
Situated approximately 1,300 light-years from our planet, the Southern Beehive Cluster stretches across a vast expanse of space, spanning a remarkable 66 light-years in diameter. Within its confines, more than 100 stars twinkle gracefully, with their ages estimated to fall between a range of 110 million to 135 million years.
This luminous cluster stands out as a prominent feature in the night sky, easily discernible to the unaided eye as a hazy, ethereal patch. The credit for its discovery goes to the pioneering French astronomer Nicolas Louis de Lacaille, who, armed with a modest ½-inch refractor in 1751, first observed this celestial wonder. While a ½-inch refractor may appear small, it possesses the ability to gather 3.3 times as much light as the fully dark-adapted human eye.
For those equipped with a 6-inch telescope, a closer inspection may reveal the presence of around 75 stars within the cluster, although this task can prove to be quite challenging. Notable denizens of the Southern Beehive Cluster include two luminous magnitude 5 red giants and a trio of binary star systems.
The Tarantula Nebula, also known as NGC 2070, is a mesmerizing Emission Nebula that lies not within our own Milky Way galaxy but rather within one of its satellite galaxies, the Large Magellanic Cloud. This celestial wonder is situated at an astonishing distance of approximately 160,000 light-years from our Solar System and spans an impressive 1,862 light-years in diameter.
The Tarantula Nebula captivates with its extraordinary luminosity, to the extent that if it were positioned as near to Earth as the Orion Nebula, it would cast shadows and dominate a staggering 60% of the horizon. Such is the brilliance of this cosmic jewel.
Notably, the Tarantula Nebula holds the distinction of being the most dynamic and active starburst region within the Local Group of galaxies. This distinction arises from its unique location on the forefront of the Large Magellanic Cloud, where it encounters the relentless force of ram pressure, resulting in the stripping of gas and dust from the nebula. The consequential compression of the interstellar medium within the Tarantula Nebula is at its zenith, driving the prolific birth of new stars and igniting a celestial fireworks display of unprecedented scale.
47 Tucanae, also known as NGC 104, stands as a remarkable testament to the grandeur of our Milky Way galaxy. This dazzling globular cluster ranks as the second-largest and second-brightest of its kind within our galaxy. Situated at a staggering distance of 16,000 light-years from Earth, it graces the constellation Tucana (The Tucan bird).
Even to the naked eye, 47 Tucanae presents itself as a conspicuous stellar gem, resembling a solitary star. When observed through binoculars, it transforms into a captivating, albeit fuzzy, celestial blob. Omega Centauri, another well-known globular cluster, is the only one that surpasses 47 Tucanae in size and brightness.
Within the confines of this celestial marvel, a staggering 1 to 2 million stars come together in cosmic harmony. The cluster boasts an expansive diameter of approximately 120 light-years and possesses stars that have gracefully aged over 10 billion years. A remarkable fact is that the average distance separating stars at the heart of this cluster amounts to roughly 10% of a light-year, more than 100 times the diameter of our own solar system.
In a remarkable discovery, announced in February 2017, indirect evidence emerged suggesting the possible presence of an intermediate-mass black hole within the heart of 47 Tucanae, adding yet another layer of intrigue to this already captivating cosmic ensemble.
In October, Mercury and Mars remain concealed by the brilliant glare of the Sun, making them invisible to the naked eye. Meanwhile, Venus will embark on an intriguing celestial journey through the Leo constellation (The Lion). On the morning of Tuesday, October 24th, Venus achieves its greatest elongation in the West. From this point onwards, Venus will gradually make its way closer to the Sun in our morning sky.
The night sky offers a captivating spectacle this month, with Jupiter and Saturn taking centre stage. Jupiter, the largest planet in our solar system, can be observed throughout the night as it gracefully moves between the constellations of Cetus (The Sea Monster), and Aries (The Ram). Saturn, with its stunning rings, graces the constellation of Aquarius (The Water Bearer), for most of the night and descends toward the horizon in the early morning hours.
For those keen on exploring the outer reaches of our solar system, Uranus makes an appearance in the Taurus constellation (The Bull), late in the evening throughout October. Neptune, on the other hand, can be found nestled between the constellations of Pisces (The Fish), and Cetus, providing a unique opportunity for stargazers to spot this distant ice giant.
Planet | When It Rises Or Sets |
---|---|
Mercury | Lost in the Sun’s glare |
Venus | At the start of October, it’ll rise at 03:42 am (AWST), and by the end of the month, it’ll rise at 03:14 am (AWST) |
Mars | Lost in the Sun’s glare |
Jupiter | At the start of October, it’ll rise at 09:00 pm (AWST), and by the end of the month, it’s viewable throughout the night |
Saturn | At the start of October, it’ll set at 04:29 am (AWST), and by the end of the month, it’ll set at 02:28 am (AWST) |
Uranus | At the start of October, it’ll rise at 09:40 pm (AWST), and by the end of the month, it’ll rise at 07:38 pm (AWST) |
Neptune | At the start of October, is viewable throughout the night, and by the end of the month, it’ll set at 03:34 am (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Southern Taurid Meteor Shower is set to grace our night skies from September 10th to November 2nd, with its peak performance anticipated on the night of October 13th/14th. For the best chance to see them, step outside at around 01:00 am (AWST), as that’s when the radiant point of the Southern Taurids will reach its zenith in the northern section of our night sky. In the forthcoming 2023 display, you can expect to witness approximately 5-10 meteors per hour, thanks to the fortunate proximity of the Moon to its New Moon phase, which ensures no light pollution from it.
This captivating celestial show originates from Comet 2P/Encke, a periodic comet known for completing an orbit around the Sun every 3.3 years. Notably, much like Halley’s Comet, it bears the name of the individual who calculated its orbital path, rather than the one who first spotted it. The history of Comet Encke dates back to January 17, 1786, when Pierre Méchain initially recorded its presence. However, it wasn’t until 1819 that Johann Franz Encke meticulously computed its orbit, unveiling its true periodic nature.
On Saturday, October 14th, an extraordinary celestial event is set to unfold as the Moon positions itself directly between the Earth and the Sun. This captivating occurrence will give rise to an Annular Solar Eclipse, a rare spectacle that will predominantly grace the skies of North and Central America. During an Annular Solar Eclipse, the Moon takes centre stage by aligning precisely with the Sun, albeit not entirely covering it. Instead, it allows the Sun’s radiant outer edges to create a mesmerizing “ring of fire,” known as an annulus (derived from the Latin word for ring), encircling the Moon.
The Moon’s apparent smaller size during this phenomenon is a result of its placement near its farthest point from Earth, referred to as apogee. This celestial synergy promises an awe-inspiring visual display, offering a remarkable glimpse into the intricate dance of our cosmic neighbours.
Event | UTC Time | Time in Perth (AWST) |
---|---|---|
First location to see the partial eclipse begin | 14th Oct at 15:03:50 | 14th Oct at 11:03:50 pm |
First location to see the full eclipse begin | 14th Oct at 16:10:11 | 15th Oct at 12:10:11 am |
Maximum Eclipse | 14th Oct at 17:59:32 | 15th Oct at 01:59:32 am |
Last location to see the full eclipse end | 14th Oct at 19:49:01 | 15th Oct at 03:49:01 am |
Last location to see the partial eclipse end | 14th Oct at 20:55:16 | 15th Oct at 04:55:16 am |
Our friends at TimeandDate.com will be live-streaming the eclipse so we won’t miss out. To watch the live stream, you can click here.
The Orionids Meteor Shower has captivated skywatchers for over two centuries, offering a timeless display of celestial wonder. This mesmerising event is a result of Earth’s journey through the remnants left behind by the iconic Comet Halley, a cosmic connection that has bestowed this shower with its name.
The encounter with the debris field commences around October 2nd, treating observers to sporadic meteors until November 7th. However, the grand spectacle reaches its zenith on the night of October 21st/22nd, promising a meteoric flurry that could grace the night sky with up to 10 meteors per hour, especially in areas devoid of light pollution. A celestial blessing for skywatchers this year is the Moon, which is poised to set shortly after the Orion constellation rises above the horizon, ensuring optimal viewing conditions.
To make the most of this celestial extravaganza, set your alarm for the early hours and venture out around 02:00 am (AWST). The key to witnessing the Orionids in all their glory is to gaze directly east around midnight and then shift your attention towards the North as the night progresses towards sunrise. This time-honoured celestial event promises a breathtaking experience for those willing to rise at these early hours and marvel at the wonders of the night sky.
Mark your calendars for Sunday, October 29th, when a celestial spectacle is set to unfold. On this remarkable day, the Moon will gracefully position itself between the Earth and the Sun, giving rise to a Partial Lunar Eclipse that will be visible across vast swathes of the globe, including Europe, Asia, Australia, Africa, Antarctica, a significant portion of South America, and even some regions in North America.
During a Partial Lunar Eclipse, the Earth takes its place between the Sun and the Full Moon, though their alignment is not absolute. This celestial ballet results in only a portion of the Moon’s visible surface slipping into the Earth’s inner shadow, known as the Umbra. As the last lunar eclipse of 2023, this event holds particular significance for stargazers worldwide.
For those in Perth, the eclipse will last an hour and 17 minutes. Consequently, observers will catch only a glimpse of a small section of the Moon briefly ensconced within the Earth’s umbra. Nevertheless, this celestial phenomenon serves as a testament to the cosmic wonders that grace our night skies and offers a moment of reflection on the grandeur of our universe.
Event | UTC Time | Time in Perth (AWST) | Visible in Perth |
---|---|---|---|
Penumbral Eclipse begins | 28 Oct at 18:01:48 | 29 Oct at 2:01:48 am | Yes |
Partial Eclipse begins | 28 Oct at 19:35:25 | 29 Oct at 3:35:25 am | Yes |
Maximum Eclipse | 28 Oct at 20:14:05 | 29 Oct at 4:14:05 am | Yes |
Partial Eclipse ends | 28 Oct at 20:52:40 | 29 Oct at 4:52:40 am | Yes |
Penumbral Eclipse ends | 28 Oct at 22:26:25 | 29 Oct at 6:26:25 am | No, below the horizon |
Our friends at TimeandDate.com and Perth Observatory will be live-streaming the eclipse so we won’t miss out. To watch the live stream, you can click here.
The Dumbbell Nebula, also known as M27 or NGC 6853, stands as a striking example of a planetary nebula nestled within the constellation of Vulpecula, often referred to as “The Little Fox.” This celestial marvel is located at a staggering distance of 1,360 light-years from our vantage point, stretching across a vast expanse of 3 light-years.
With an age ranging between 9,000 to 15,000 years, the Dumbbell Nebula boasts a rich history, notably being the first planetary nebula discovered by the renowned Charles Messier back in 1764.
In essence, a planetary nebula represents a distinct class of emission nebulae. However, it differs significantly from star formation regions like the Orion Nebula (M42). Instead of fostering the birth of new stars, planetary nebulae mark the twilight years of a stellar entity. These objects emerge from the aftermath of a nova-style explosion, wherein a dying star expels a shell of material. Illuminated by the penetrating ultraviolet radiation emanating from the residual star, this shell transforms into an emission nebula, expanding outward as a vibrant and ethereal testament to the star’s final stages.
At the heart of the Dumbbell Nebula lies a diminutive yet compelling white dwarf star. It possesses a mere 5% of the Sun’s diameter and approximately half of its mass, epitomizing the transformation that stars undergo as they near the end of their life cycle. These planetary nebulae typically assume spherical shapes and appear diminutive, often resembling planetary disks when viewed through modest telescopes. Regrettably, their existence is short-lived, spanning just a few tens of thousands of years before fading into the cosmic tapestry and dwindling in density as they drift away from their progenitor star.
When scrutinized at high resolution, as was accomplished by the Hubble Space Telescope in 2001, the inner regions of the Dumbbell Nebula reveal an intricate tapestry of irregularities and knots. These substructures exhibit dimensions spanning 20 to 60 million kilometres and carry a mass equivalent to approximately three Earths each. The Dumbbell Nebula, with its captivating intricacies, stands as a testament to the profound beauty and complexity inherent in the cosmos.
The Wild Duck Cluster, a celestial gem also known as M11 or NGC 6705, graces the constellation of Scutum, often referred to as “The Shield,” at a remarkable distance of 6,200 light-years from our home planet. This open cluster spans an expansive 25 light-years and plays host to a dazzling assembly of 2,900 stars, all with an estimated age of around 220 million years. The moniker “Wild Duck Cluster” finds its origins in the arrangement of its brighter stars, which collectively form a triangular pattern reminiscent of a squadron of ducks in flight, soaring through the cosmic expanse.
The cluster’s history is intertwined with the annals of astronomy. It was first documented by the diligent eye of German astronomer Gottfried Kirch from the Berlin Observatory in 1681. Later, in 1733, William Derham achieved the remarkable feat of resolving its constituent stars into individual points of light. The distinguished French astronomer Charles Messier added this stellar ensemble to his celebrated catalogue in 1764, marking it as a standout entry due to its distinction as the most remote open cluster visible to the naked eye within the Messier Catalogue.
Despite the apparent togetherness of its stars, the Wild Duck Cluster is, in reality, a congregation of stars only loosely bound to one another. As time unfurls, this cosmic gathering is destined to disperse, its members gradually ejected one by one. The inexorable force of gravity exerted by neighbouring celestial objects will contribute to this gradual dissolution. In a few million years, the Wild Duck Cluster will become a memory, a testament to the ever-evolving dynamics of our celestial neighbourhood.
The Great Sagittarius Cluster (Messier 22), also known as M22 or NGC 6656, stands as a captivating globular cluster nestled in the vicinity of the Milky Way’s central bulge, residing at a staggering distance of 10,600 light-years from our home planet. This densely populated congregation of stars finds its celestial abode in the constellation Sagittarius, often associated with “The Archer,” and it boasts the distinction of being one of the brightest globular clusters gracing our night sky. M22 holds a prominent place in the annals of astronomical study, as it ranks among the first globular clusters to undergo extensive scrutiny. In terms of proximity, it is one of the closest globular clusters to our own Solar System, second only to Messier 4 in nearness. Spanning a colossal 100 light-years in diameter, this cluster plays host to an impressive gathering of approximately 83,000 stars, all of which have been in existence for a staggering 12 billion years.
Locating M22 is a delight for skywatchers, as it can be easily discerned with the naked eye under favourable conditions. Positioned a mere 2.5 degrees northeast of Kaus Borealis, the star adorning the apex of Sagittarius’ Teapot, M22 appears as a faint, ethereal patch of light when observed through binoculars. For those armed with small telescopes, the cluster’s brightest stars reveal themselves, while larger instruments unveil a breathtaking tapestry of stars that populate this celestial congregation.
As an intriguing twist, M22 showcases a distinct astronomical motion, receding from us at a velocity of 149 km/s. Its remarkable character doesn’t end there, as two black holes were confirmed within its confines by the Chandra X-ray telescope in 2012. This revelation hints at the possibility of an array of black holes ranging from 5 to 100 within the cluster, shedding light on the intriguing interplay between these enigmatic entities and the stars within the cluster. This interaction could well account for the cluster’s unusually expansive central region.
In an even more extraordinary turn of events, Messier 22 distinguishes itself as one of only four globular clusters known to house a planetary nebula. This rarity is shared only with Messier 15, situated in the constellation Pegasus, within Messier’s celebrated catalogue. The presence of these planetary nebulae within globular clusters adds a layer of mystique to the already captivating world of celestial formations, beckoning astronomers and stargazers alike to delve deeper into the cosmic wonders of our universe.
The String of Pearls Galaxy, designated as NGC 55, emerges as a captivating example of a Magellanic-type barred spiral galaxy. Situated approximately 6.5 million light-years distant within the boundaries of the constellation Sculptor, also known as “The Sculptor’s Studio,” this celestial beauty spans an astounding expanse of 70,000 light-years.
What distinguishes NGC 55 from the multitude of galaxies adorning our night sky is its unique presentation; we observe it almost edge-on. This orientation lends an air of enigma to its appearance, with subtle asymmetries and discernible traces of dust near its central bulge. Adding to its allure, NGC 55 exhibits the dynamic process of star formation, further accentuating the vibrancy of its stellar population.
In some astronomical circles, this resplendent galaxy also goes by the moniker “The Whale Galaxy,” a whimsical name that conjures images of aquatic giants traversing the cosmic seas. NGC 55, along with its celestial neighbour NGC 300, holds the distinction of being among the closest galaxies to our own Local Group, a cosmic gathering that encompasses the Milky Way and neighbouring galaxies. The proximity between NGC 55 and NGC 300 suggests that they share a gravitational bond, forming an intriguing celestial duo that beckons exploration and inquiry.
The String of Pearls Galaxy, with its enigmatic presence and proximity to our galactic neighbourhood, continues to captivate the imagination of astronomers and stargazers alike, serving as a testament to the intricate and wondrous tapestry of the cosmos.
In the upcoming month, there are some celestial movements worth noting. Mercury will gradually disappear from our view, getting lost in the Sun’s brilliance during the first few days of September. However, it will make a reappearance in the eastern morning sky around mid-September, still situated within the constellation of Leo (The Lion). Keep an eye out for Mercury’s greatest elongation in the West on Monday, September 22nd, before it retreats towards the Sun.
As for Venus, it will commence September positioned between the constellations of Cancer (The Crab) and Hydra (The Serpent). By the month’s end, it will have journeyed to the front paws of the constellation Leo. Mars, on the other hand, will be making its way through the constellation of Virgo (The Virgin) throughout the entire month of September. To catch a glimpse of Mars, direct your gaze low in the western sky during the early evening hours.
Shifting our attention to the giant planets, Jupiter can be found nestled between the head of the constellation Cetus (The Sea Monster) and the feet of the constellation Aries (The Ram) in the night sky. Saturn, another magnificent sight, will grace the middle of the constellation of Aquarius (The Water-Bearer).
For those interested in spotting Uranus, it will rise late at night within the constellations of Taurus, precisely situated between Jupiter and the Pleiades Cluster. Lastly, Neptune can be observed during the early night hours positioned amidst the top fish in the constellation Pisces and the tail of Cetus (The Whale).
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of September, it sets at 06:45 pm (AWST), and by the end of the month, it’ll rise at 05:22 am (AWST) |
Venus | At the start of September, it rises at 04:49 am (AWST), and by the end of the month, it’ll rise at 03:43 am (AWST) |
Mars | At the start of September, it sets at 07:45 pm (AWST), and by the end of the month, it’ll set at 07:25 pm (AWST) |
Jupiter | At the start of September, it rises at 11:03 pm (AWST), and by the end of the month, it’ll rise at 09:04 pm (AWST) |
Saturn | At the start of September, it’ll be visible the whole night, and by the end of the month, it’ll set at 04:33 am (AWST) |
Uranus | At the start of September, it rises at 11:42 pm (AWST), and by the end of the month, it’ll rise at 9:44 pm (AWST) |
Neptune | At the start of September, it rises at 07:15 pm (AWST), and by the end of the month, it’ll be viewable the whole night |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
Get ready for the start of the Zodiacal light season, commencing on September 1st. This mesmerising phenomenon occurs as the Sun approaches the September Equinox, which falls on September 22nd. During this time, sunlight scatters off dust particles dispersed along the ecliptic plane—the apparent path of the Sun’s motion on the celestial sphere as observed from Earth. The best opportunities to witness this enchanting pearly glow are during the spring and autumn seasons, particularly at dawn or dusk. This is because the steep angle of the ecliptic in relation to our horizon allows for optimal visibility. In the Southern Hemisphere, dusk is favoured during the September Equinox season, while in the Northern Hemisphere, it’s dawn. The opposite holds true near the March equinox.
To catch a glimpse of the zodiacal light, venture out approximately an hour after sunset or an hour before dawn. Choose a location with minimal light pollution, aiming for a dark site. Any interference from nearby cities or faint glows on the horizon can diminish the ethereal radiance of the zodiacal light. As you observe, you’ll notice a slender pyramid-shaped glow tracing the length of the ecliptic plane, creating a truly captivating display.
On Saturday, September 23rd, at 02:49 pm (AWST), we will witness the Southward Equinox—an astronomical event that signifies the onset of fall in the Northern Hemisphere and the arrival of spring in the Southern Hemisphere. At this precise moment, the Sun’s declination, as observed from Earth, reaches 0. The equinoctial points, where the celestial equator intersects with the imaginary path of the Sun known as the ecliptic, define this significant occurrence. Throughout the 21st century, the September Equinox will fall on either September 22nd or 23rd, until the year 2092 when it will consistently take place on September 21st every fourth year.
The term “Equinox” originates from Latin and translates to “equal nights.” During this event, day and night are nearly equal in duration across the globe, and the Sun rises precisely due east and sets due west as seen by an observer. The Full Moon nearest to the September Equinox holds the title of the “Harvest Moon,” a period when farmers utilise the extended twilight to gather their crops. In 2023, the Harvest Moon will grace the sky on September 29th.
It’s worth noting the term “Equilux”, which distinguishes the true Equinox from the point when the duration of daylight matches the duration of night-time. Several factors contribute to this disparity, including the time it takes for the physical diameter of the Sun to clear the horizon, atmospheric refraction, and the observer’s precise location within their respective time zone. The Equilux occurs within a few days of either Equinox, accounting for these variations.
51 Pegasi (also known as 51 Peg and SAO 90896) is a Sun-like star situated 50 light-years away from Earth in the constellation of Pegasus. With an estimated age of 6.1 to 8.1 billion years, it is slightly older and 24% larger than our Sun. While this star might not typically be featured in a “must-see” article, it gained significant attention due to a remarkable object orbiting around it. On October 6th, 1995, Michel Mayor and Didier Queloz of the University of Geneva made an announcement in the journal Nature that forever changed our understanding of exoplanets. 51 Pegasi became the first Sun-like star known to harbour an exoplanet in its orbit. The exoplanet, initially designated as 51 Pegasi b and now officially named Dimidium, defied expectations with its peculiar characteristics. It boasted a size twice that of Jupiter while completing a full orbit around its star in a mere four days. This discovery served as the prototype for a new category of gas giants called Hot Jupiters. For astronomers who had presumed that our solar system represented the norm, this revelation was truly astounding and captured the imagination of budding stargazers, including my younger self.
The planet’s detection relied on the “Wobble Method,” a technique that utilized a sensitive spectroscope to measure the subtle yet regular velocity changes in the star’s spectral lines, equivalent to about 70 meters per second. These variations were attributed to the gravitational influence exerted by the planet located a mere 7 million kilometres from its host star. The significance of this achievement was recognized when Michel and Didier were awarded the 2019 Nobel Prize in Physics. Despite being twice the size of Jupiter, the planet exhibits a lower mass. This can be attributed to its superheated atmosphere, which expands into a dense but tenuous layer enveloping the planet. Beneath this layer, the gases constituting the planet’s composition reach such high temperatures that the planet emits a red glow. It is possible that silicate clouds exist within the planet’s atmosphere. Additionally, the planet is tidally locked, meaning it consistently presents the same face to its host star.
The Pegasus Cluster, also known as Messier 15 (M15) and NGC 7078, is a captivating globular cluster located approximately 35,700 light-years away from Earth in the constellation of Pegasus (The Winged Divine Stallion). Jean-Dominique Maraldi first discovered it in 1746, and it is estimated to be an astounding 12.5 billion years old, making it one of the oldest known globular clusters. Spanning 175 light-years in diameter, it stands as one of the most densely packed clusters within the Milky Way galaxy. Within its core lies a remarkable phenomenon known as “core-collapse,” indicating a contraction process, and it exhibits a central density cusp surrounding a potential central black hole.
The Pegasus Cluster is a bustling neighbourhood for over 100,000 stars, showcasing a remarkable array of variable stars and pulsars, including a captivating double neutron star system. Additionally, it is home to the first planetary nebula discovered within a globular cluster back in 1928. Since then, only three others have been identified in globular clusters. When observing the Pegasus Cluster, it appears as a hazy star when viewed through binoculars or a small telescope. However, with larger aperture telescopes (at least 6″), individual stars within the cluster become discernible, revealing the stunning beauty and intricate details of this celestial jewel.
The Helix Nebula, also known as NGC 7293, located in the constellation of Aquarius, is a mesmerising planetary nebula. Among the closest planetary nebulas to Earth at a distance of approximately 655 light-years, it shares a striking resemblance in appearance to nebulas such as the Cat’s Eye Nebula and the Ring Nebula. These nebulas possess similar size, age, and physical characteristics, akin to the Dumbbell Nebula, differing primarily in proximity and the equatorial viewing angle, which lends the Helix Nebula its unique appearance. In popular culture, it has been likened to the “Eye of Sauron” or the “Eye of God.”
Unlike the star-forming regions found in nebulae like The Orion Nebula (M42), a planetary nebula marks the late stage in the life cycle of a star. It occurs when a star expels a shell of material in a nova-style explosion. The intense ultraviolet radiation from the progenitor White Dwarf star causes the previously expelled shell of gas to fluoresce brilliantly, creating an emission nebula. From our perspective, the gases expelled from the star give the impression of a helix structure, as if we are peering down its winding path.
Spanning a modest 2.5 light-years, the expansion of the entire planetary nebula is estimated to have commenced around 6,560 years ago, with the inner disk beginning its expansion approximately 12,100 years ago. Spectroscopic observations indicate an expansion rate of 40 km/s for the outer ring and around 32 km/s for the inner disk. Thus, based on the ratio of size to expansion rate, the age of the nebula is estimated to be between 10 and 1200 years. Notably, the Helix Nebula was the first planetary nebula discovered to contain cometary knots. These impressive, tadpole-shaped structures are likely remnants of the star’s final stages, aptly named “cometary knots” due to their resemblance to comets, featuring luminous heads and ethereal tails. These knots are believed to result from the Rayleigh-Taylor instability. The ionised inner nebula, with its low density and high expansion velocity, propels the denser, slowly expanding, predominantly neutral material that was previously shed during the Asymptotic Giant Branch phase of the star’s evolution.
The Sculptor Galaxy, also known as the Silver Coin Galaxy and NGC 253, is a barred galaxy located in the Sculptor constellation (The Sculptor’s Studio). Stretching approximately 67,000 light-years in width, it was first discovered by Caroline Herschel in 1783 while she was conducting a search for comets. Belonging to the Sculptor group of galaxies, which is centred around the south galactic pole and often referred to as “The South Polar Group,” this galaxy may be the closest group of galaxies beyond our own Local Group, situated approximately 11.5 million light-years away from Earth.
Renowned as a Starburst galaxy, NGC 253 boasts a multitude of stellar nurseries where a significant number of hot, young blue stars are continuously forming. This vibrant star formation activity is attributed to a past collision with a dwarf galaxy that occurred roughly 200 million years ago. As a consequence, the rate of star birth in NGC 253 is exceptionally high, leading to subsequent supernova explosions.
The intense radiation emitted by these young stars causes the surrounding hydrogen gas to radiate a vivid pink glow. NGC 253 is abundant in Wolf-Rayet stars, which originate as massive, hot stars with masses approximately 20 times that of the Sun and rapidly shed their hydrogen envelopes through high-velocity stellar winds. Additionally, the Silver Coin Galaxy exhibits a significant amount of dust, although it lacks clearly defined lanes similar to those observed in the Milky Way Galaxy.
With an apparent magnitude of 7.2, the Sculptor Galaxy is the second easiest galaxy to observe, surpassed only by the Andromeda Galaxy and excluding the Milky Way’s satellite galaxies, the Large and Small Magellanic Clouds. Under favourable viewing conditions, it can be discerned with binoculars, appearing approximately two-thirds the size of a full moon along its longest axis.
At the beginning of the month, Mercury, Venus, and Mars can be spotted low in the western evening sky within the constellation of Leo (The Lion). Throughout August, Mercury will remain in Leo, closely interacting with Mars in the middle of the month. On Monday, August 10th, Mercury will reach its greatest elongation in the East before gradually returning towards the Sun. On the other hand, Venus will only be visible during the first week of August before becoming obscured by the Sun’s glare. It will remerge in the morning sky in the middle of August, positioning itself between the constellations of Cancer (The Crab) and Hydra (The Serpent). Mars, initially located in Leo, will transition into the constellation of Virgo (The Virgin) around the middle of August.
Jupiter can be found in the night sky positioned between the head of the constellation of Cetus (The Sea Monster) and the front feet of the constellation of Aries (The Ram). Meanwhile, Saturn can also be observed in the middle of the constellation of Aquarius (The Water-Bearer).
Uranus rises late at night within the constellations of Taurus, situated prominently between Jupiter and the Pleiades Cluster. Lastly, Neptune can be located during the early night-time hours, positioned between the top fish in the constellation of Pisces and the tail of the constellation of Cetus.
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of August, it sets at 07:41 pm (AWST), and by the end of the month, it’ll sets at 06:52 pm (AWST) |
Venus | At the start of August, it sets at 07:09 pm (AWST), and by the end of the month, it’ll rise at 04:53 am (AWST) |
Mars | At the start of August, it sets at 08:21 pm (AWST), and by the end of the month, it’ll sets at 07:51 pm (AWST) |
Jupiter | At the start of August, it rises at 01:00 am (AWST), and by the end of the month, it’ll rise at 11:07 pm (AWST) |
Saturn | At the start of August, it rises at 7:37 pm (AWST), and by the end of the month, it’ll be visible the whole night |
Uranus | At the start of August, it rises at 01:45 am (AWST), and by the end of the month, it’ll rise at 11:44 pm (AWST) |
Neptune | At the start of August, it rises at 09:21 pm (AWST), and by the end of the month, it’ll rise at 07:19 pm (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The eagerly anticipated Perseids meteor shower is nearly upon us, reaching its peak on the night of the 13th/14th of August. This captivating display is primarily visible in the Northern Hemisphere and takes its name from the constellation of Perseus (The slayer of Medusa and the rescuer of Andromeda), the apparent source of these meteors. The Perseids shower remains active from mid-July to the end of August. Observers in the Northern Hemisphere can typically witness a meteor rate exceeding 100 meteors per hour during this period. However, for those of us in Australia, the chances of observing the Perseids are limited to the northern part of the country. To catch a glimpse, one must venture out around 5 am when the meteors will appear very low on the horizon in the northern direction.
Fortunately, this year’s viewing experience will be favourable, as a Waxing Crescent Moon graces the eastern sky during the optimal viewing time. While there will be a slight amount of light pollution from the Moon, it will not significantly hinder the enjoyment of the meteor shower.
Albireo, a remarkable double star located in the constellation of Cygnus (The Swan), lies approximately 390 light-years away from our vantage point. Serving as the “beak star” in the constellation Cygnus the Swan, Albireo’s name has an intriguing origin, stemming from various mistranslations between Greek, Arabic, and Latin languages. It offers a captivating sight, particularly to modest telescopes, showcasing a wide double star with striking colour contrast.
Albireo can be found in the northern sky, but it remains visible for only a few months during the late winter and spring seasons. The primary star of Albireo exhibits a warm yellow/amber hue, while its companion star displays a distinct blue/green colouration. Although the primary star is also a binary system, it is too close and dim to be discerned without the aid of large telescopes and exceptional observing conditions. Remarkably, these stars orbit around each other over a span of approximately 100,000 years.
The primary star boasts impressive characteristics, with approximately five times the mass and 1,200 times the brightness of our Sun. However, it possesses a cooler surface temperature of approximately 4,100 Kelvin. On the other hand, the secondary star weighs about 3.2 times the mass of our Sun and shines with a brightness roughly 230 times greater. With a surface temperature of approximately 12,000 Kelvin, it exhibits a hotter nature compared to its primary counterpart.
The Dumbbell Nebula, also known as Messier 20 (M20) and NGC 6514, is a captivating planetary nebula situated in the constellation of Vulpecula (The Little Fox). It possesses an age ranging between 9,000 and 15,000 years. Unlike the Orion Nebula, which is a stellar nursery, the Dumbbell Nebula represents the later stages in the life cycle of a star that has shed a shell of material through a nova-like explosion. This expelled gas shell is illuminated by the intense ultraviolet radiation emitted by the remaining star, resulting in an emission nebula surrounding the expanding shell of gases. Planetary nebulae typically exhibit a spherical shape and are relatively small in size, which often gives them the appearance of planetary discs when observed through smaller telescopes. These phenomena have a relatively short lifespan of a few tens of thousands of years before gradually fading and becoming more diffuse as they move away from their progenitor star.
Spanning nearly 3 light-years in diameter, the Dumbbell Nebula is situated at a comparable distance to the Orion Nebula, approximately 1,360 light-years away. However, visually, it appears much smaller, measuring about one-fourth the diameter of a Full Moon. The Dumbbell Nebula presents an intriguing prolate spheroid shape when observed from our perspective along the plane of its equator. At its core lies a white dwarf star, which serves as the progenitor of the nebula. This white dwarf is approximately 5% larger in diameter and 50% more massive than our Sun, making it larger than most known white dwarfs. The inner region of the Dumbbell Nebula exhibits a rugged appearance, adorned with numerous knots and structures, as revealed in high-resolution images captured by the Hubble Space Telescope in 2001. These substructures, ranging in size from 20 to 60 million kilometres (equivalent to fractions of an astronomical unit), harbour a mass of approximately three times that of the Earth.
The Scorpius Globular Cluster, also known as Messier 4 (M4) and NGC 6121, is among the closest globular clusters to Earth, positioned approximately 7,200 light-years away. It resides in close proximity to the star Antares within the constellation of Scorpius (The Scorpion) and is characterized by its relatively loose structure, making it one of the smallest globular clusters with a diameter of 55 light-years. The cluster, estimated to be 12.2 to 13 billion years old, contains around 100,000 stars arranged in a roughly spherical configuration. Notably, it exhibits an intriguing central bar composed of stars, a feature first recognized by William Herschel in 1783.
Situated within the halo of our galaxy, the Scorpius Globular Cluster occupies the spherical region encircling the pancake-shaped galactic disk. While it orbits the centre of the galaxy, it resides outside the plane of the galactic disk. It was initially discovered by Philippe Loys de Chéseaux in 1746, and M4 holds the distinction of being the first globular cluster ever resolved into individual stars using a telescope. Through binoculars, it appears as a diffuse patch of light, but even a 4-inch telescope can resolve some of its brightest stars. Its apparent size is slightly smaller than that of the full moon.
For the Astrophotographers out there, let’s explore the fascinating Cat’s Paw Nebula (NGC 6334), an emission nebula and star-forming region nestled within the constellation of Scorpius (The Scorpion). Also known as the Bear Claw Nebula, it was initially discovered by astronomer John Herschel in 1837 during his observations from the Cape of Good Hope in South Africa. This nebula finds its place in the Carina–Sagittarius Arm of the Milky Way, located approximately 5,500 light-years away from Earth.
Spanning an impressive 320 light-years, the Cat’s Paw Nebula captivates observers with its vivid display. In the visible spectrum, it predominantly emits a striking red hue from ionized hydrogen atoms, while bursts of blue originate from oxygen atoms. Encompassing an area in the night sky slightly larger than the full Moon, this nebula boasts numerous star-forming regions that have been identified through infrared and radio emissions. It stands as one of the most active stellar nurseries, birthing massive stars within the Milky Way Galaxy. The nebula owes its radiant glow to the presence of hot, young stars deeply embedded within its core. Some of these celestial giants exceed ten times the mass of our Sun and have emerged within the past few million years, perpetuating the ongoing cycle of stellar birth and evolution within this cosmic marvel.
Mercury will make its reappearance in the second week of July, appearing very low on the western horizon. It will begin the week situated in the constellation of Cancer (The Crab), but as the month progresses, it will transition into the constellation of Leo (The Lion), drawing nearer to Venus and the star Regulus. Venus can be observed in close proximity to Mars, positioned low in the constellation of Leo until the middle of the month when they gradually separate in the night sky. Meanwhile, Mars will continue its journey through the constellation of Leo, reaching its hind feet by the end of July.
Jupiter can be located between the head of the constellation of Cetus (The Sea Monster) and the front feet of the constellation of Aries (The Ram) during night-time. Saturn is also visible in the middle of the constellation of Aquarius (The Water-Bearer) in the night sky. Uranus rises late at night within the constellations of Taurus (The Bull), precisely positioned between Jupiter and the Pleiades Cluster. Lastly, Neptune can be found during the early night-time hours, situated between the top fish in the constellation of Pisces (The Fish) and the tail of the constellation of Cetus.
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of July, it’s not visible as it’s in the Sun’s glare, and by the end of the month, it’ll set at 07:38 pm (AWST) |
Venus | At the start of July, it sets at 08:37 pm (AWST), and by the end of the month, it’ll set at 07:14 pm (AWST) |
Mars | At the start of July, it sets at 08:53 pm (AWST), and by the end of the month, it’ll set at 08:22 pm (AWST) |
Jupiter | At the start of July, it rises at 02:41 am (AWST), and by the end of the month, it’ll rise at 1:04 am (AWST) |
Saturn | At the start of July, it rises at 9:50 pm (AWST), and by the end of the month, it’ll rise at 07:42 pm (AWST) |
Uranus | At the start of July, it rises at 03:42 am (AWST), and by the end of the month, it’ll rise at 01:49 am (AWST) |
Neptune | At the start of July, it rises at 11:27 pm (AWST), and by the end of the month, it’ll rise at 9:24 pm (AWST) |
Conjunctions involve object(s) in the Solar System and/or more distant objects, such as a star. It’s an apparent phenomenon in which multiple objects which aren’t close together appear close in the sky and it’s caused by the observer’s perspective.
In an occultation, an object passes across the line of sight between an observer and another object. A solar eclipse is an occultation of the Sun by the Moon.
The Delta Aquarids meteor shower is set to reach its peak on the night of July 30th/31st, primarily favouring observers in the southern hemisphere, including those in Perth. This captivating shower remains active from July 12th to August 23rd, with the number of meteors seen per hour varying between 10 to 20. However, in 2023, the presence of a Full Moon in the night sky will result in reduced visibility of meteors from this shower.
The radiant point for the Delta Aquarids lies within the constellation of Aquarius, becoming visible from 08:00 pm (AWST) on the 30th. For optimal viewing, it is advisable to wait until around 03:00 am on August 1st. Although the Delta Aquarids lack a prominent peak, they consistently grace the night sky with their presence throughout their active period. It is believed that the comet 96P/Machholz 1, once part of the ancient stream of Kreutz Sungrazing comets, serves as the source for the Delta Aquariids.
The Hercules Cluster, also known as Messier 13 (M13) and NGC 6205, is an impressive Globular Cluster situated approximately 22-25,000 light-years away from Earth within the constellation of Hercules (The son of Zeus). Spanning about 168 light-years in diameter, this cluster boasts several hundred thousand stars with an astonishing age of 11.5 billion years. The stars within the M13 population are remarkably densely packed, over a hundred times more so than those in the Sun’s vicinity. This close proximity sometimes leads to stellar collisions, giving rise to the formation of new stars known as “Blue Stragglers”.
First discovered by Edmond Halley in 1714, Messier 13 was later catalogued by Charles Messier in his renowned collection of celestial objects that should not be mistaken for comets. When observed through binoculars, the Hercules Globular Cluster appears as a circular patch of radiant light, while a telescope with a diameter of at least 4″ allows for the resolution of individual stars within M13’s outer regions, appearing as minute pinpoints of light.
An intriguing event involving the Hercules Cluster took place in 1974 when the Arecibo message was transmitted from the Arecibo Observatory. This message contained encoded information encompassing details about the human race, DNA, atomic numbers, Earth’s position, and more, serving as an experiment to establish contact with potential extraterrestrial civilizations residing in the cluster. However, due to the cluster’s motion through space, there is uncertainty regarding whether the message will eventually reach its intended destination and be received by the inhabitants of Messier 13.
The Wild Duck Cluster, also known as Messier 11 (M11) and NGC 6705, is an open cluster situated 6,120 light-years away in the constellation of Scutum (the Shield). Renowned for its richness and compactness, M11 is among the most massive open clusters, spanning a diameter of 190 light-years and containing over 2,900 stars estimated to be around 316 million years old. The cluster was initially discovered by Gottfried Kirch in 1681, and its name originates from the arrangement of brighter stars resembling a flying flock of ducks. Notably, M11 holds the distinction of being the most distant open cluster visible to the naked eye among the 26 included in the Messier catalogue.
The Butterfly Cluster, also referred to as Messier 6 (M6) and NGC 6405, is an open cluster comprised of approximately 120 stars located within the constellation of Scorpius (The Scorpion). Positioned around 1,600 light-years away from Earth, the stars within this cluster are estimated to be between 55 and 100 million years old. Visually, the Butterfly Cluster appears slightly smaller than a Full Moon, with dimensions measuring 12 light-years in width and 25 light-years in length. It is crucial to avoid confusing M6 with its brighter neighbour, M7, situated southeast of it.
While the discovery of the Butterfly Cluster by Giovanni Hodierna predates 1654, his data was not unearthed until the 1980s. It was independently discovered by Philippe de Chesaeux in 1745/6, and Messier officially catalogued it as M6 in 1764. Remarkably, as of January 2022, the Butterfly Cluster remains one of the few objects within the Messier Catalogue yet to be photographed by the Hubble Space Telescope.
DY Crucis is a Carbon Star located in close proximity to Mimosa (Beta Crucis) and the Jewel Box Cluster (NGC 4755) in the constellation of the Crux (The Southern Cross), positioned 4,077 light-years away from Earth. A Carbon Star represents a giant star in the later stages of its evolution. While sharing similarities with red giants, Carbon Stars possess atmospheres with higher carbon-to-oxygen ratios. They often exhibit variability, altering their size and brightness over time.
DY Crucis captivates observers with its distinctive cherry red hue, a result of its atmosphere containing carbon “soot” in the form of carbon and carbon compounds. This soot scatters and reflects blue light while allowing red light to pass through, similar to the phenomenon observed during sunsets. Furthermore, the star’s surface temperature contributes to its appearance, as DY Crucis registers below 3,500 Kelvin, classifying it as a cool star and lending it a reddish tone. To provide context, the temperature of our Sun is approximately 5,778 Kelvin.
As we move into the month, Venus and Mars continue to be the only evening planets to grace the night sky. Venus can be seen in the north-west, moving from the constellation of Gemini (The Twins) to join Mars in the constellation of Cancer (The Crab) after the first few days of the month, and then will continue chasing Mars into the constellation of Leo (The Lion) near the end of the month. On Sunday the 4th of June, Venus will reach its greatest elongation in the East before gradually making its way back towards the Sun.
Mercury, on the other hand, can be spotted low in the north-east, moving from the constellation of Aries (The Ram) to Taurus (The Bull) at the end of the first week of the month, before gradually fading into the morning twilight towards the end of the third week of the month. Jupiter can be seen in the northeast in Aries, above Mercury, while Saturn can be seen in the northwest in Aquarius (The Water-Bearer). Uranus, on the other hand, will be visible in the constellations of Taurus by the end of the month. Lastly, Neptune can be found in between the constellations of Pisces and Cetus (The Sea Monster), providing an enchanting view for stargazers who are keen on exploring the night sky.
Planet | When It Rises Or Sets |
---|---|
Mercury | At the start of May, it rises at 05:07 am (AWST), and by the end of the month, it’ll disappear into the Sun’s glare |
Venus | At the start of May, it sets at 08:30 pm (AWST), and by the end of the month, it’ll set at 08:38 pm (AWST) |
Mars | At the start of May, it sets at 09:25 pm (AWST), and by the end of the month, it’ll set at 08:54 pm (AWST) |
Jupiter | At the start of May, it rises at 04:12 am (AWST), and by the end of the month, it’ll rise at 02:45 am (AWST) |
Saturn | At the start of May, it rises at 11:44 pm (AWST), and by the end of the month, it’ll rise at 09:50 pm (AWST) |
Uranus | At the start of May, it rises at 05:32 am (AWST), and by the end of the month, it’ll rise at 03:45 am (AWST) |
Neptune | At the start of May, it rises at 01:24 am (AWST), and by the end of the month, it’ll rise at 11:31 pm (AWST) |
Conjunctions are a phenomenon that involves objects within our Solar System, as well as more distant objects such as stars. From the observer’s perspective, it appears as though multiple objects that aren’t close together, in reality, appear close in the sky.
On the other hand, an occultation is an event that occurs when one celestial body passes across the line of sight between an observer and another celestial body. One example of an occultation is a solar eclipse, which occurs when the Moon passes in front of the Sun from the perspective of the observer.
The June Solstice marks an astronomical event that occurs twice a year, with the next one taking place on Wednesday the 21st of June at 10:57 pm (AWST). It signifies the beginning of winter in the southern hemisphere and the start of summer in the northern hemisphere. This event happens when the Sun’s declination equals 23.5 degrees south as observed from Earth. The Tropic of Cancer is the line of latitude where the Sun passes directly overhead during the June solstice, although in modern times, the Sun is in the astronomical constellation of Gemini in mid-June due to precession.
During the June solstice, the southern rotational pole of the Earth is tilted away from the Sun, initiating its long apparent journey northward until December. The wobbling of Earth’s axis, known as the Precession of the Equinoxes, takes about 26,000 years to complete one full cycle. This means that over the average lifespan of 72 years, the equinoctial points would have moved one degree, which is approximately twice the diameter of a full Moon.
The June Solstice is an essential event for astronomers as it helps in understanding the mechanics of the Earth’s axial tilt and its impact on the Earth’s climate and seasons. Many cultures celebrate the June solstice with festivals and traditions, including the ancient Druids who celebrated it as the “Alban Heruin” or “light of the shore.”
The Omega Nebula, also known as Messier 17, is a beautiful emission nebula located in the constellation Sagittarius. It’s located approximately 5,500 light years away from Earth and spans a distance of about 15 light years. It is an active region of star formation and contains a large number of young, hot stars. These stars ionize the surrounding gas, causing it to glow with a beautiful pinkish-red colour.
The nebula is divided into several different sections, each with its own unique shape and appearance. The central region of the Omega Nebula contains a cluster of stars that are responsible for illuminating the gas and dust in the nebula. The surrounding gas and dust have been shaped by the intense radiation and stellar winds from these stars, creating a beautiful and intricate pattern of filaments and pillars. Observing the Omega Nebula requires a telescope or a pair of binoculars, as it is a relatively faint object. A narrowband filter can be used to enhance the contrast between the nebula and the surrounding sky, bringing out its beautiful colours and intricate details.
The nebula was first discovered in 1745 and recorded by Charles Messier in 1764, and it’s so named because it appears like the Greek letter Omega. Alternatively, it may be seen as a horseshoe with a “tail” to one side giving it, perhaps, a swan’s neck appearance. It is also referred to as the Swan, Checkmark, Lobster and Horseshoe Nebula.
The Trifid Nebula and Lagoon Nebula are two of the most famous and beautiful celestial objects in the southern sky. Both nebulae are located in the constellation of Sagittarius and are relatively close to each other in the sky. They are popular targets for amateur astronomers and can be observed with binoculars or a small telescope.
The Trifid Nebula, also known as Messier 20 and NGC 6514, is an emission and reflection nebula that is located approximately 5,200 light-years away from Earth and is 15 light-years across. The name “trifid” refers to the three dark lanes that divide the nebula into different sections. The nebula contains a cluster of young stars, which are responsible for illuminating the gas and dust in the nebula. The Trifid Nebula is particularly striking because of its vivid pink, red, and blue colours.
The Lagoon Nebula, also known as Messier 8 and NGC 6523, is an emission nebula that is located approximately 4,100 light years away from Earth, and it’s been estimated to be 100 light-years wide and 50 light-years high. A very young nebula, perhaps less than 10,000 years, it’s named after the lagoon-shaped dust lane that runs through its centre. The Lagoon Nebula is also home to a cluster of young stars, which are responsible for illuminating the gas and dust in the nebula. The colours of the Lagoon Nebula range from deep red to blue-green.
Both the Trifid and Lagoon Nebulas are active regions of star formation, and are rich in molecular gas and dust, with the Lagoon Nebula containing many “Bok globules” forming stars. In addition, the Trifid and Lagoon Nebulas are both part of the larger Sagittarius Molecular Cloud complex, which is one of the largest and most massive molecular clouds in the Milky Way.
The Ptolemy Cluster, also known as Messier 7 or NGC 6475, is a stunning open star cluster located in the constellation of Scorpius. It is named after the ancient astronomer Ptolemy, who first recorded its existence in 130 AD. The cluster is one of the brightest and most spectacular in the sky and is a popular target for amateur astronomers. The Ptolemy Cluster contains approximately 100 stars, but it is surrounded by a larger cloud of gas and dust, which makes it difficult to determine its exact size. The stars in the cluster range in age from a few million to a few billion years, and they are all located relatively close to each other.
Observing the Ptolemy Cluster does not require a telescope, as it is visible to the naked eye under dark skies. However, a good pair of binoculars or a small telescope will allow you to see the individual stars within the cluster. The best time to observe the cluster is during the Southern Hemisphere winter months when it is highest in the sky.
The Pavo Globular Cluster, also known as NGC 6752, is one of the closest and brightest globular clusters and is located in the southern constellation of Pavo, approximately 13,000 light-years away from Earth. The Pavo Globular Cluster is estimated to be about 10 billion years old, and it contains hundreds of thousands of stars. The cluster has a relatively compact size, with a diameter of approximately 100 light-years, making it one of the densest globular clusters known. The stars in the cluster are tightly packed together, and their gravitational interactions keep them bound to each other, creating a beautiful and unique cosmic structure.
One of the most striking features of the Pavo Globular Cluster is its colour. The stars in the cluster range from blue to red, with a large number of yellow stars in between. This diversity of colours creates a breathtaking view that is worth observing. Observing the Pavo Globular Cluster requires a good telescope, and preferably a dark sky with little light pollution. The Pavo Globular Cluster is not only a stunning astronomical object to observe, but it is also an important object for astronomical research. Its proximity and brightness make it an ideal laboratory for studying the dynamics and evolution of globular clusters.