Mercury will viewable in the morning sky in the Aquarius (The Water Bearer) Constellation with Neptune at the beginning of the month. The planet will rise at 04:22 am (AWST) at the start of the month and through the month will move through the Pisces (The Fish) Constellation before at the very end of the month it’ll be lost to the Sun’s glare. Venus can be found in Taurus (The Bull) Constellation this month and at the start of April and will set at 08:16 pm (AWST). By the end of month, Venus will set at 07:38 pm (AWST).
Mars throughout April will be in the Capricornus (The Sea Goat) Constellation as an orange dot. The planet rises very close to Saturn at the beginning of the month at 00:51 am (AWST) and by the end of the month, it’ll rise at 00:33 am (AWST) and it’ll will be over 17 degrees away from Saturn. Jupiter, the king of the planets can be still be found in the Sagittarius (The Centaur with a Bow) Constellation this month. At the beginning of the month, it’ll rise at 00:22 am (AWST) and by the end of April, it’ll rise at 10:40 pm (AWST). Saturn will be in the Capricornus (The Sea Goat) Constellation during the month of April rising at the beginning of the month at 00:54 am (AWST) and by the end of the month it’ll rise at 11:00 pm (AWST).
Neptune, the last planet in our Solar System can be found in the early morning sky between the Aquarius (The Water Bearer) and Pisces (The Fish) Constellations for the whole of April. The planet will rise at 04:43 am (AWST) at the beginning of the month and by the end of the month at 02:53 am (AWST)
Conjunctions and Occultation
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. An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer.
- 02/04/20 – Alignment of the Moon, Pollux and Castor (Where to look)
- 04/04/20 – Conjunction of the Moon and Regulus (Where to look)
- 08/04/20 – Conjunction of the Moon and Spica (Where to look)
- 11/04/20 – Conjunction of the Moon and Antares (Where to look)
- 14/04/20 – Alignment of the Moon, Mars, Jupiter and Saturn (Where to look)
- 15/04/20 – Conjunction of the Moon, Mars, Jupiter and Saturn (Where to look)
- 16/04/20 – Alignment of the Moon, Mars, Jupiter and Saturn (Where to look)
- 17/04/20 – Alignment of the Moon, Mars, Jupiter and Saturn (Where to look)
- 22/04/20 – Conjunction of the Moon and Mercury (Where to look)
- 26/04/20 – Alignment of the Moon, Venus and Aldebaran (Where to look)
- 29/04/20 – Conjunction of the Moon, Pollux and Castor (Where to look)
Astronomical Events This Month:
In the early morning of the night of the 22nd/23rd of April while most of us were asleep the Lyrids meteor shower will hit the Earth’s atmosphere at their peak. The Lyrids have been observed for at least 2,600 years which makes them the longest observed meteor shower. The oldest description of the shower comes from the Chinese who described on the night of the March 16, 687 BC that “stars fell like rain”. The records show that this shower has been more active in the past but has since turned into a minor shower with the occasional surprise which keeps the Lyrids always a bit interesting.
The cause of the Lyrids is the long-period comet with a very boring name of Comet C/1861 G1 (Thatcher). The comet has a rough orbit of about 415 years and was discovered by A. E. Thatcher on the 5th of April 1861 as it was making its last pass around The Sun. This year the Lyrids will peak on the night of the 22nd and 23rd of April and will appear to come from the constellation of Lyra. Lyra will appear in the sky over the Perth hills around 1:00 am so you should go out around 3:00 am when the Lyra constellation is at its zenith (highest point in the sky) and look slightly above the bright star (Vega) low in the North. Give your eyes 15 minutes to fully adjust to the lighting conditions and look very low between North and North East. While it’s always best to find a nice park or a large open space for best viewing of a meteor shower, you can go out to our front or back yard and still get a good view. Fortunately for this year, the Moon is a new moon phase so there’ll be no light pollution, so if you get out of Perth’s light pollution you’ll easily see the fainter meteors.
Things to Look at This Month
The Eight-Burst Planetary Nebula (NGC 3132) also known as the Southern Ring Nebula is a bright planetary nebula in the constellation Vela. It’s 2,000 light-years away from us and is 0.4 light-years across. The name “planetary nebula” refers to the round shape and in reality, nothing to do with planets but due to it appearing like a planet. The round shape is actually huge shells of gas ejected a star as it nears the end of its life and are expanding away from the central star at a speed of 9 miles per second.
Images of the nebula shows two stars close together within the nebulosity with the white dwarf that created the nebula being the fainter of these two stars. The white dwarf is at a temperature of 100,000 K and has now blown off its layers. The intense ultraviolet radiation comes of the white dwarf is making the nebula fluoresce brightly.
The Leo Triplet (M66 Group), Located in the constellation Leo is a small group of galaxies about 35 million light-years away. This galaxy group consists of three spiral galaxies M65, M66, and NGC 3628. To see the best out of this galaxy cluster, its best to get out to the country with telescope. To plan at astronomy trip to the country it’s best to check out Astrotourism WA Map.
Messier 65 (NGC 3623) is an intermediate spiral galaxy that is slightly smaller than our galaxy at 90,000 light years in diameter and is 35 million light-years away from us. It’s low in dust and gas, and there is little star formation in it, although there has been some relatively recently in the arms. The ratio of old stars to new stars is correspondingly quite high.
Messier 66 (NGC 3627), is another intermediate spiral galaxy in the group. M65 and M66 make a popular pair for observers as they’re separated by only 20 degrees. M66 spiral shape has a weak bar feature in the centre and loosely wound arms. It lies closer to us than M65 at 31 million light-years away and it appear to be slightly larger than M65 at 95,000 light-years in diameter. We are seeing it at an angle, and it has striking dust lanes and bright star clusters along sweeping spiral arms. Between 1973 and 2016, five supernova have been detected in this galaxy (SN 2016cok, 2009hd, 1997bs, 1989B, and 1973R) with SN 2016cok, a Type IIa supernova being detected in 2016 by the All-Sky Survey Automated Survey for Supernovae.
The Hamburger Galaxy (NGC 3628) also known as Sarah’s Galaxy is an unbarred spiral galaxy about 35 million light-years away and it has an approximately 300,000 light-years long tidal tail. Its most striking feature is the broad and obscuring band of dust located along the outer edge of its spiral arms, effectively transecting the galaxy to the view from Earth. Due to the presence of an x-shaped bulge which is visible in multiple wavelengths, there is an argument that the galaxy is a barred spiral galaxy with the bar seen end on. Simulations have shown that bars often form in disk galaxies during interactions and mergers which could be the case for the Hamburger Galaxy as it’s known to be interacting with its two large neighbours Messier 65 and Messier 66.
The Jewel Box:
An open cluster the Jewel Box can be found very close in the Crux (Southern Cross) Constellation, the Jewel Box is located some 6,440 light years away from Earth and is 14 light-years across. The cluster contains just over 100 stars, and with an estimated age of its stars being just 14 million years, this star cluster is one of the youngest clusters that we’ve found. The Jewel Box cluster also has some of the brightest stars in the Milky Way galaxy. These stars are supergiants and the red, white and blue stars in the centre of the cluster look very much like the lights of a traffic light.
Eta Carinae and the Carina Nebula:
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, those 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’s 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 the smaller partner orbiting in a highly elliptical orbit of 5.5 years. The Carinae Nebula (NGC 3372), which surrounds Eta Carinae, is a large, bright star-formation region which has produced a number of very massive stars including Eta Carinae. At around 260 light years the Carina Nebula is around 7 times the size of 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 Eta Carinae nebula.
Omega Centauri or NGC 5139 is the largest and brightest globular cluster of 180 in Milky Way and is the second largest known, with only Mayall II in the Andromeda Galaxy being larger coming ins about twice its mass. The Globular cluster is located in Centaurus Constellation and it’s a naked eye ‘star’ and clearly visible in binoculars as a ‘fuzzy blob’. Omega Centauri contains at least 3 million stars and the cluster has a diameter of roughly 150 light-years and the stars are roughly 12 billion years old. The average distance between the stars at the centre is around 10% of a light year or more than 100 times the diameter of our solar system. It may be a dwarf galaxy that has been captured and disrupted by the Milky Way galaxy and measurements of its star movement by Hubble has indicated that a black hole may be located at the core of the cluster.