Unlike most of the population, amateur astronomers can welcome the change from BST to GMT because the skies darken that bit earlier in the evenings. Let’s hope they stay clear so that we can enjoy the stars and planets.
The following chart represents the night sky at 10.00pm GMT on the 8th of November and at 9.00pm GMT on the 23rd November. To use the chart, face your southern horizon at the appropriate time and you will see the stars in the chart.
With Cassiopeia on the top right of the chart and Andromeda to the right hand side there should be no difficulty in finding your location in the night sky. The constellations Aries and Triangulum have been mentioned in recent months so the new ones this month are Perseus- the Greek mythological hero, Auriga- the Charioteer and Taurus- the Bull.
The constellation, Perseus, lies in the Milky Way below and to the left of Cassiopeia and to the left of Andromeda. A lot of imagination is required to make out the mythological hero but the line of stars containing Algol is meant to represent his left arm with his left hand holding the head of Medusa (represented by Algol) whom he has slain. The string of stars above that represents his right arm holding his sword while the downward string of stars to the left is his left leg. The brightest star is Mirphak, a 1.8 magnitude yellow supergiant but the better known Algol is an eclipsing binary with the eclipse lasting 10 hours with a period of less than three days. A nice challenge might be to watch Algol regularly to establish when the next minimum will occur then observe it for two hours either side of the minimum when most of the change in brightness happens. The magnitude dips from 2.1 to 3.4 during the eclipse and can be observed with the naked eye. The magnitude of Almach in Andromeda is about the same as Algol at its brightest and can be used as a useful comparison. (You can’t resolve the two stars with the naked eye that can only be done spectroscopically.)
The constellation, Auriga, is also in the milky way and contains, Capella, the fourth brightest star visible in the northern hemisphere at magnitude 0.1 and is only 42 light years from Earth. It is a star that one soon becomes familiar with during wintertime in the northern hemisphere. Auriga forms a roughly pentagonal shape but the bottom star, Alnath, is actually in the constellation Taurus.
Our final constellation this month is a zodiacal one- Taurus- the Bull. It lies just below Auriga and the star Alnath represents the tip of one of its horns with an adjacent star below and to the left representing the tip of its second horn and leading down to the brightest star in the constellation, Aldebaran. It is easily picked out because it is a red giant with a magnitude around 1.0 said to represent the eye of the bull. Taurus contains two open clusters- the ‘V’ shape to the right of Aldebaran and representing the face of the bull is an open cluster called the Hyades while to the north-west roughly in the direction of Algol is the more famous open cluster, the Pleiades or Seven Sisters. The latter is one of my favourites for unaided observation but if you can use binoculars much more is revealed in both of these.
Something to look out for
Jupiter will be at opposition on Friday 3rd November, visible most of the night from 6.00pm GMT onwards and at maximum altitude about midnight over the southern horizon. It will also be at its closest approach to the earth (perigee) at the same time.
On Thursday 9th November there will be a daytime occultation of Venus by the Moon between 9.45am and 10.45 am. It may not be possible to witness the whole event as the day brightens and always be careful with the Sun above the horizon and if possible use a building to block a direct line of sight to the Sun.
The Pleiades are well placed for viewing and will be at their highest point above the southern horizon about midnight on Saturday 18th.
There are two lunar close approaches to look out for. The Moon and Saturn above the southern horizon after 6.00pm on Monday 20th and the Moon and Jupiter best seen about 10.00pm on Saturday 25th.