Astronomy

Astronomy
Astronomy Guide to the Night Sky – June 2018

With the Newbury Astronomical Society

(This will be the last issue until September)
Click on the image to enlarge, ‘right click’ to copy the image or ‘close window’ to return

The chart above shows the night sky looking south at about 22:00 BST on 15th June.  West is to the right and east to the left.  The point in the sky directly overhead is known as the Zenith and is shown at the upper centre of the chart.  The curved brown line across the sky at the bottom is the Ecliptic or Zodiac.  This is the imaginary line along which the Sun, Moon and planets appear to move across the sky.  The constellations through which the ecliptic passes are known as the constellations of the ‘Zodiac’.

Constellations through which the ecliptic passes this month are: Gemini (the Twins), Cancer (the Crab), Leo (the Lion), Virgo (the Virgin), Libra (the Scales) and Sagittarius (the Goat) on the South Eastern horizon.

The planet Venus is in the constellation of Cancer and is very easy to find in the west as soon as the sky darkens.

Ursa Major is almost directly overhead as can be seen by the location of the ‘Zenith’ (the point directly overhead) on the chart above.  It is one of the best known and easily recognised constellations.  It is also known as ‘the Plough’ or the ‘Big Dipper’ to the Americans.  It does actually resemble a saucepan more than anything else and is very easily recognised as a saucepan in the sky.

Ursa Major is very easy to find and because it is ‘circumpolar’ (never sets below the horizon) it is always somewhere in our night sky.  As it is so easy to find it is a good place to start exploring the night sky.  The two stars of the ‘pan’ opposite the ‘saucepan handle’ (known as the Pointers) can be used to find Polaris the Pole Star (or North Star) in Ursa Minor.  Follow the ‘Pointers’ up out of the pan to find Polaris.  By following an imaginary line off the end of the saucepan handle will show the way to Arctaurus the bright red star (it looks more orange) in Boӧtes.

The constellation of Boӧtes does not have anything interesting to search out but the bright star Arctaurus is very beautiful.  It is a Red Giant and appears distinctly orange to the naked eye and even more so when using binoculars or a telescope.  Boӧtes is also a good point to use to find other constellations like Hercules.  Hercules is to the east (left) of Boӧtes and is host to the beautiful Globular Cluster Messier 13 (M13).

By following the ‘Pointers’ in Ursa Major down they point the way to the constellation of Leo (the Lion).  The stick figure of Leo does actually look a little like a lion.  The bright star Regulus in Leo sits right on the Ecliptic and is often seen close to the Moon and sometimes the planets as they appear to move along the ecliptic.

To the east of Leo is the quite indistinct constellation of Virgo.  It does have one fairly bright star called Spica.  It is classified as a Class B1 Giant but is in fact a very close binary star.  The two stars are very close and orbit the common centre of gravity every four Earth days.  Their gravity pulling on each other has made them ‘egg’ shaped.

To the east of Virgo is the small and rather indistinct constellation of Libra.  This constellation is easy to find this year because it is host to the very bright planet Jupiter.  Libra is followed along the ecliptic by the constellation of Sagittarius which is host to the beautiful ringed planet Saturn.  There are also a lot of star clusters and other interesting objects in the direction of Sagittarius as this is where the centre of our Galaxy the Milky Way is to be found.

Just coming into view in the east is the Summer Triangle defined by the stars: Deneb (in Cygnus), Vega (in Lyra) and Altair (in Aquila).

Follow this link to see the full ‘Monthly What’s Up’ guide to the night sky:

http://naasbeginners.co.uk/Whats_up/2017_2018/June2018.htm

To see a full version of this article and a guide to the night sky with charts, read the Newbury Astronomical Society (NAS) – Monthly Magazine for Beginners on the NAS website or come along to the next Beginners meeting on Wednesday 19th September 2018, for details click on the link below.

For details visit the NAS website at: www.naasbeginners.co.uk

Leave a comment