Interesting reflection

Ken Kennedy of Dundee Astronomical Society tells us what we can expect to see in the September sky. “With the summer triangle of stars being displaced from its southerly position as the earth travels in orbit round the sun,” he says, “the tip of the nose of Pegasus, the flying horse, reaches the meridian at about 10pm.

“Think of the horse as being inverted then it is easy to follow the fainter line of stars back to the more obvious square of stars which form the body of the horse. The topmost easterly star of the square leads back to the constellation Andromeda where the Andromeda Galaxy can be seen with binoculars.

“The galaxy can easily be found by scanning the sky along the ‘hind leg’ of the horse to the next bright star then up a bit. Look at the beginning or near the end of the month when the moonlight will not interfere and it should appear as a fuzzy patch in binoculars.

“On a dark, clear night you should just be able to see this with the unaided eye. This collection of more than 100 billion stars, at a distance of two and a half million light years, is the furthest object most people can see without optical aid. It is an interesting reflection to think that the light reaching your eye started out when our ancestors began using the first primitive tools.

“Another relatively close ‘local’ galaxy can just be made out with binoculars close by in the constellation Triangulum. Having found the Andromeda Galaxy, move downwards slowly towards a thin triangle of stars and before you reach them you may just see a faint hazy disc which is the Triangulum Galaxy, or M33 in Charles Messier’s catalogue.

“On the first day of September there is an annular eclipse of the sun but it will only be visible along a narrow strip running from central Africa to Madagascar. An annular eclipse occurs when the diameter of the moon does not quite cover the sun and a thin rim of the sun remains round the moon.

“At the full moon following that eclipse, on September 16, there is a penumbral eclipse of the moon between 6 and 10pm. The moon rises in mid-Scotland at 7.30pm so, given a low easterly horizon, the later part of the eclipse could be seen.

“Mercury may be seen low in the east before sunrise for a few days round the 28th. Venus sets only half an hour after the sun during the month and will not be visible.

“Mars is very low towards the southsouth-west at 8pm and sets at around 9pm. Jupiter is not visible during September. Saturn is quite close to Mars and sets at about the same time. Mars and Saturn will not be easily seen this month.

“The moon is new on the 1st, at first quarter on the 9th, full on the 16th and at last quarter on September 23”.