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What’s In July’s Night Skies


Both Mercury will Mars in the early July evening sky. Both will be found in the Constellation of Cancer (The Crab) before both will move into the Sun’s glare in the first weeks of July.

Jupiter, the king of the planets can be still be found in the Ophiuchus (The Serpent-bearer) Constellation this month. It’ll be viewable at the start of the night throughout the month, at the beginning of July, Jupiter will set at 05:47 am (AWST) and by the end of the month it’ll at 03:38 am (AWST). Saturn is still below Jupiter in the Constellation of Sagittarius (The Centaur with a Bow) and it’ll be viewable at the start of the night throughout the month. By the end of the month, Saturn will start setting before sunrise at 05:52 am (AWST).

Mercury and Mars on the 01/07/19 at 06:30 pm. Image Credit: Stellarium Jupiter and Saturn on the 15/07/19 at 08:00 pm. Image Credit: Stellarium

Uranus can be found in the Constellation of Cetus (The Sea Monster) in the early evening this month. It’ll rise at 02:26 am (AWST) at the start of July and by the end of the month it’ll rise at 00:32 am (AWST). Neptune, the last planet in our Solar System can be found in the early morning sky in between the Constellations of Aquarius (The Water Bearer), Cetus (The Sea Monster) and Pisces (The Fish) the whole of July. The planet will rise at 10:41 pm (AWST) at the beginning of July and by the end of the month at 08:42 pm (AWST)

Uranus on the 15/07/19 at 05:00 am. Image Credit: Stellarium Neptune on the 15/07/19 at 02:00 am. Image Credit: Stellarium

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.

  • 04/07/19 – Conjunction of the Moon, Mercury and Mars (Where to look)
  • 06/07/19 – Conjunction of the Moon, Algieba and Regulus (Where to look)
  • 10/07/19 – Conjunction of the Moon and Spica (Where to look)
  • 13/07/19 – Conjunction of the Moon, Antares and Jupiter (Where to look)
  • 14/07/19 – Conjunction of the Moon, Antares, Jupiter and Saturn (Where to look)
  • 15/07/19 – Conjunction of the Moon, Antares, Jupiter and Saturn (Where to look)
  • 16/07/19 – Conjunction of the Moon and Saturn (Where to look)
  • 28/07/19 – Conjunction of the Moon and Aldebaran (Where to look)
  • 29/07/19 – Conjunction of the Moon, Aldebaran and Betelgeuse (Where to look)

Astronomical Events This Month:

Total Solar Eclipse:

On Wednesday the 2nd of July the Moon passes between the Earth and Sun and will totally eclipse the Sun for a small region on the Earth between 0:55 am (AWST) and 05:50 am (AWST). Unfortunately, Perth will miss out on this total solar eclipse the path of totality will start in the South Pacific Ocean and move through Chile and Argentina. The rest of South America will see either a Partial or Annular Solar Eclipse.

July's Total Lunar Eclipse viewing map. Image Credit: A Total Lunar Eclipse. Image Credit: John Finney Photography

Partial Lunar Eclipse:

On the early morning of Wednesday, the 17th of July the Moon will move behind the Earth and partially into the Earth’s umbra (Inner shadow). The duration of this partial eclipse will be 2 hours, 58 minutes. We’ll see the Moon partially in shadow. The rest of the Moon is covered by the outer part of the Earth’s penumbra (Outer shadow). This month’s eclipse Partial Eclipse will begin at 04:02 am, with the Moon covered the most at 05:30 am. The Partial Eclipse will finish by 07:00 am.

July's Partial Lunar Eclipse viewing map. Image Credit: A Partial Lunar Eclipse. Image Credit: Carol Redford

The Delta Aquarids

The Delta Aquariid meteors are due to peak on the night of the 28th/29th of July and they’ll favour southern hemisphere observers, which includes observers in Perth. The shower is active from the 12th of July to 23rd of August and they can vary in their hourly rate each year between 10 to 20 meteors per hour. In 2019, the Delta Aquariids are expected to have a good hourly rate of (meteors per hour) due to there being a lovely waning crescent moon in the Just before sunrise.

The Delta Aquarids is located in the constellation of Aquarius and it can be viewable from 08:00 pm on the 28th, but it’ll be best to wait until around 03:00 am on the 30th. The source of the Delta Aquariids is believed to be 96P/Machholz 1 comet which was part of the unnamed ancient stream of Kreutz sungrazing comets.

The Delta Aquarids on the 29/07/19 at 01:00 am. Image Credit: Stellarium A meteor from the Delta Aquarids. Image Credit: David S. Brown

Things to Look at This Month:

Trifid and Lagoon Nebulas:

The Trifid Nebula (M20 & NGC 6514) and Lagoon Nebula (M8 & NGC 6523) can be found close to in the constellation of Sagittarius.

The Trifid Nebula is an emission (pink) and reflection (blue) nebula, with open star cluster, found in Sagittarius. The Trifid (Meaning “divided into three lobes”) comes from the three-pronged dark lanes (dark nebulae) through the nebula that blocks off the light behind. The nebula is 2,660 light-years away and is 15 light-years across.

The central star formation “nursery” where hot young stars power the emission nebulae. Infrared telescopes have shown there 30 embryonic and 120 newborn stars not yet bright enough to emit light in the visible light part of the light spectrum. The new stars are very young at 400,000 years old with the central star in the nebula actually a cluster of four star systems, two of which are close binaries, making six stars in all.

The Lagoon Nebula is, sometimes called the “Hourglass Nebula” (not to be confused with the true “Hourglass Nebula” in the constellation of Musca), is a very young nebula, perhaps less than 10,000 years. The nebula is further away than the Trifid Nebula at 4,100 light-years away and it’s a lot bigger with the nebula being 100 light-years across and 50 light-years high. It is one of the finest and brightest star-forming regions in the sky and contains many “Bok globules”, which contain dense cosmic dust and gas from which star formation may take place. The central emission area is energised by a bright ultraviolet “O4” class star and it’s a relatively easy object for amateur astrophotographers.

Trifid and Lagoon Nebulas on the 15/07/19 at 21:00 pm. Image Credit: Stellarium Trifid Nebula and Lagoon Nebula. Image Credit: Paulo Cacella

Ptolemy Cluster:

The Ptolemy’s Cluster (M7 & NGC 6475) is a large open cluster near the sting of the tail of the constellation of Scorpius. While it’s 980 light years away from us, it’s large enough to be seen with the unaided eye in a dark sky and is a nice sight in binoculars. The cluster is 25 light-years across and it contains around 100 stars in total. It was first described by the Greek-Roman astronomer Ptolemy in 130 AD from which it gets its common name of Ptolemy’s cluster. The colour of the stars in this cluster is predominately yellow, indicating this is an older cluster, with an estimated age of 260 million years. Clusters which contain many hot blue stars, like the Pleiades, are considerably younger.

Ptolemy Cluster on the 15/07/19 at 21:00pm. Image Credit: Stellarium Ptolemy Cluster. Image Credit & Copyright: Lorand Fenyes

The Jewel Box:

An open cluster which can be found very close in the Crux (Southern Cross) Constellation, the Jewel Box (NGC 4755) 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.

Jewel Box on the 15/07/19 at 9:00 pm. Image Credit: Stellarium The Jewel Box in perspective - Image credit: ESO, NASA/ESA, Digitized Sky Survey 2 and Jesús Maíz Apellániz

Omega Nebula:

The Omega Nebula is located in the Sagittarius constellation. This emission nebula is regarded as one of the brightest and most massive star-forming regions of the Milky Way. Within the nebula, the radiation from an open cluster of ~35 hot, young stars heats the surrounding gas to incandescence. There could be as many as 800 stars in the associated cluster.

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.

Omega Nebula on the 15/07/19 at 09:00 pm. Image Credit: Stellarium M17 - Omega Nebula. Image Credit: Putman Mountain Observatory

Omega Centauri:

Omega Centauri (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.

Omega Centauri on the 15/07/19 at 9:00 pm. Image Credit: Stellarium Omega Centauri. Image Credit: Perth Observtory Volunteer Andrew Lockwood

Phases of The Moon:

July 2019 Moon phases

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