ASTRONOMY GUIDE TO THE NIGHT SKY – JANUARY 2023
With the Newbury Astronomical Society
The chart above shows the night sky at 19:00 on 15th January 2023
Click on the chart to enlarge and click to the side of the chart to close
The chart above shows the night sky looking south at about 19:00 GMT (early evening) on 15th January. 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 (in red) 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 brightest stars often appear to form a group or recognisable pattern; we call these ‘Constellations’.
Constellations through which the ecliptic passes this month are: Aquarius (the Water Carrier), Pisces (the Fishes), Aries (the Ram), Taurus (the Bull), Gemini (the Twins), Cancer (the Crab) and Leo (the Lion).
Moving over the western horizon is the constellation of Pegasus (the Winged Horse). The main feature of Pegasus is the square formed by the four brightest stars. This asterism (shape) is known as the Great Square of Pegasus. The square is larger than might be expected but once found is easier to find again. There is a very nice Globular cluster in Pegasus, it is known as Messier 15 (M15). It is a lovely sight to see using a telescope.
Once the square is found the pointer to Andromeda is the top left star of the square named Alpheratz. Strangely Alpheratz is officially not part of Pegasus but is designated as Alpha (α) Andromedae. The constellation of Andromeda is host to the only ‘naked eye’ Galaxy that is known as Messier 31 (M31). It is the most distant object that can be seen with our naked eyes (2.4 million light years away). It is quite easy to find using binoculars and is well place at this time of the year.
The easiest way to find M31 is to follow the line of stars from Alpheratz and locate the second star in the line which is shown as Mirach on the chart above. From Mirach follow a slightly fainter short line of stars to the north (above) Mirach to the second star. Just to the right of this star is the faint fuzzy patch of light that is M31 the Great Andromeda Galaxy. See the following pages.
Taurus is easy to find this month because it is almost overhead and Mars is shining brightly in the constellation. The most obvious star in Taurus is the lovely Red Giant Star called Aldebaran. It appears slightly orange to the ‘naked eye’ but it is very obviously orange when seen using binoculars or a telescope. Aldebaran is located at the centre of the ‘flattened’ X shape formed by the brightest stars in Taurus. At the end of the top right (upper west) arm of the ‘X’ is the beautiful ‘naked eye’ Open Star Cluster Messier 45 (M45) known as the Pleiades (or the Seven Sisters). It really does look magnificent using binoculars.
Following Taurus is the constellation of Gemini (the Twins). The two brightest stars in Gemini are Castor and Pollux and they are named after mythological twins. To the north of Taurus is the odd pentagon shape of Auriga (the Charioteer). Dominating Auriga is the brilliant white star Capella which is almost directly overhead. For those with a telescope there is a line of lovely open clusters to search out in Taurus and Auriga. These are M35 in Taurus and M36, M37 and M38 in Auriga.
To the south of Taurus is the winter constellation of Orion (the Hunter). Orion is easily found by looking for his very obvious three stars of his belt. Orion is the constellation of this month and is featured in the January What’s Up see the link below.
To the east (left) of Taurus is the rather indistinct constellation of Cancer (the Crab). The stars of Cancer are quite faint and can be difficult to discern especially in a light polluted sky. It is really worth searching out Cancer using binoculars or a telescope to see the Open Cluster M44 (the Beehive Cluster). M44 is older and further away than M45 (the Seven Sisters) so is fainter than M45 but still looks lovely. It has a group of stars that resemble an old straw Beehive with bees around it.
WHERE TO FIND THE PLANETS THIS MONTH
All the planets, except Mercury and Venus are in the evening sky.
Mercury is not observable this month as it is too close to the Sun in the early morning.
Venus is emerging from its Superior Conjunction (behind the Sun) on 22nd October and is now very low and close to the south western horizon soon after sunset and difficult to see.
Mars was at its closest to Earth on 1st December but was at opposition when it actually overtook Mars on 8th December. It is now almost overhead in the constellation of Taurus.
Jupiter is bright and observable over the south western horizon. The cloud markings can be seen and the four brightest moons will be visible in binoculars or a small telescope.
Saturn has now moved over the southern western horizon and is not observable.
Uranus is in a good position for observing on the constellation of Aires (the Ram).
Neptune is still quite well placed in the southern night sky and located close to Jupiter.
Follow this link to see the full ‘Monthly What’s Up’ guide to the night sky: http://naasbeginners.co.uk/Whats_up/2022_2023/January2023.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 Magazines for Beginners on the website at: www.newburyastro .