This Month's Night Sky
Below you will find Stan Barber's guide to what you can expect to see in the night sky this month. If you would like further information regarding what you can see in the night sky this month, either email Pete Sherman or Stan Barber. Alternatively, you can come along to Sigma's next meeting (further information on Events page). Here is a useful lunar calendar for your reference.
Visit the Handy Angles page to ease your navigation around the night sky!!
August 2010
August marks the return of truly dark skies to our latitude, albeit for a few short hours. The sky view is for midnight on the 15th August. Sunrise is at 5.38am and sunset at 8.55pm. The Moon is at Last Quarter on 3rd, New on the 10th, First Quarter on the 16th and Full on the 24th.
The Planets
Just after sunset, four planets are visible to the west and southwest, Mercury being the hardest to see, if at all, very low on the western horizon in the twilight. Saturn, Mars and Venus are close to each other but all have set by 9.50pm. In contrast, Jupiter rises in the East about the same time and its elevation should provide better viewing opportunities than it has for some time. Good binoculars or a telescope will show the 4 largest Galilean moons Io, Europa, Ganymede and Callisto in order of distance from Jupiter. A nice low power view of Jupiter involves a line-up of its principle moons on one side of the planet, which happens every few days. Line-ups will occur on 5/ 6th, 12/ 13th, before dawn on the 14th, 26/ 27th and before midnight on the 29th.
The Constellations and Main Stars
Ursa Major (the Plough is in the northwest and following the pointers through Draco’s tail we find Polaris,the Pole Star, marking north. Again from the Plough, following the line formed by the handle round in a curve we find Arcturus, a red giant, and one of the brightest stars in the sky at the bottom of the fairly faint kite-shaped constellation of Bootes, the Herdsman.
Looking south the sky is dominated by the constellations of Cygnus (the Swan), Lyra (the Lyre) and Aquila (the Eagle) whose brightest stars of Deneb, Vega and Altair respectively make up the Summer Triangle. Cygnus is also known as the Northern Cross and if not immediately obvious, can be located by finding Vega a bright star almost overhead when facing South, with Cygnus lying to its left. The Swan's tail is marked by Deneb, a blue-white super giant some 3000ly away, and its head is marked by Albireo, much fainter but a celebrated double star with contrasting orange and blue-green components easily separated with a telescope or powerful binoculars. Though Aquila is less easy to distinguish, its brightest star Altair has two fainter stars flanking it forming a straight line that points to Vega.
Halfway between Albireo and Altair is Sagitta (the Arrow)a small but lovely constellation representing an arrow sailing harmlessly between the two birds. To the right of Sagitta, and on a line between Altair and Vega you will find the Coat hanger Cluster aptly named, as binoculars will reveal. To the left of Altair is another small constellation Delphinus(the Dolphin) its four principle stars forming a box shape known as Job’s Coffin. Finally, from these constellations, follow a line from Deneb through Vega and you will find an undistinguished constellation Hercules, with its wedge of stars forming ‘the keystone’. This is home to M13, a globular cluster of some one million stars and one of the showpieces of the northern sky, best seen with a telescope.
Looking to the northeast you will see a bright star above the horizon, which is Capella the brightest in Auriga (the Charioteer). Facing East follow a line from Capella to the south and you will find the constellations of Perseus, Andromeda, and the Square of Pegasus. Above Perseus and Andromeda is the unmistakeable W of Cassiopeia, and above this Cephus, but more of these constellations and their sights in next month's Bull’s Sky Views.
Meteor Shower – The Perseids
August is also the month for the Perseids meteor shower active between the 17th July and 24th August. The peak with an expected zenithal hourly rate of 75 is predicted between 7.30pm BST on 12th to 8am BST on 13th, with observations best started after 11pm when the sky is truly dark. Look northeast towards Cassiopeia and Andromeda and don’t forget to wear something warm and have a hot drink (non-alcoholic) handy. This year the waxing crescent Moon will have set around the peak period so this promises to be a good year to observe the Perseids.
Noctilucent Clouds (NLCs)
If you’ve visited our website you’ll have seen Alan Tough’s splendid picture of NLCs taken in the early hours of 5th July. August is the last month to really see NLCs if you look just after sunset but before full darkness. They are steel-grey coloured structures that exist some 50 miles up on the edge of space.
The ISS
The ISS is a morning object from the 10th to the 21st but then becomes an evening object from the 26th through into September.
For ISS times and information, as well as iridium flares, visit www.heavens-above.com
Return to Main Astronomy Information page
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