On the full moon of this month, which falls on 5th we will celebrate Kojagiri. The ``poornima'' of Ashwin month is traditionally celebrated by singing and drinking flavoured milk under the moon light. Well, most of you know about it (and much more), nothing new there. Some say that the milk kept under the moon light for sufficiently long will acquire medicinal properties. Apparently there are other benefits too. This never sounded logical to me. But I have also learned not to discredit the religious festivals and have been trying to understand the astronomical significance.Rains are almost over but the houses are still a bit damp and require fresh air to move freely inside. Winter is fast approaching but we can still move in the night without having to wear warm clothes. There is a freshness in the air. The sun is travelling southwards and nights are becoming longer. And since on the full moon day the moon is exactly opposite the sun, the moonlit hours close to the full moon will now be longer. So - so let's party.This month Algol the demon star in Perseus, the Champion (Yayati) rises above the northeastern horizon. This is a remarkable star which changes its brightness at a very regular interval. Every 2 days and 20 hours or so it brightness start falling, rather rapidly. In about 5 hours time it is about half as bright as it was before. But then it soon gains its shine and after five more hours it is back to is own self. Suitable times for us to watch this behaviour are first on 25th. On this day it will reach its minimum brightness at about two hours past midnight. That is on 26th at 02.00 IST. Then on 28th it is at its faintest at 22.49 IST.Between Cassiopeia and Perseus is a nice pair of open cluster of stars. This pair is not difficult to see with the naked eyes. But use a pair of binoculars and it is a magnificent sight. It is called ach and chi (pronounced khay rhyming with chay) Persai.Flying constellations :Well, above the eastern horizon is Pegasus, the Flying Horse (Maha Ashwa). One cannot miss the remarkable Great Square of Pegasus. The two stars at the top of the square are the Uttara-Bhadrapads and other two are Purwa-Bhadrapads. According to international convention the northeastern star of the Great Square belongs to Andromeda (Devayani). Andromeda is daughter of Cassiopeia. The location marked M31 is for the Andromeda Galaxy. Then slightly to west are Aquila, the Eagle and Cygnus, the Swan. Further west we have the musical instrument Lyra. Two human figure Hercules and Ophiuchus are now about to set.Sagittarius, the Archer is now taking a plunge into the south-western horizon. But well above the horizon are four water-related constellations. Capricornus, the Sea-Goat. This is an ancient zodiac constellation. The merry goat-legged god of the forests and groves Pan was dancing on the river bank, playing his flute. Suddenly he was attacked by a Typhoon - a fire-spitting monster. Pan plunged into the water and a miracle happened to him: his body turned into the tail of a fish, while this fore-part changed into a goat. Zeus immortalized this transformation by placing the Goat in the heaven.To the northeast of Capricornus lies Aquarius the Water-Bearer and to the southeast is Pisces Austrians, the Southern-Fish. And rising above the eastern horizon is Cetus, the Whale.The Solar System There is still time to find Uranus and Neptune in the sky. Uranus is in fact within the naked eyes limit but you will do much better if you use a pair of binoculars. You will of course require the biox for Neptune. If you have not already got the finding charts of these planets you can get those by sending me a self-addressed stamped envelope. The address is IUCAA, Post Bag No. 4, Ganeshkhind, Pune-411007. Uranus will set by about 1 hour past midnight and Neptune half an hour before Uranus.Jupiter is now well above the eastern horizon at the sunset. The day is shortest on this planet. This planet makes one rotation on its axis in just 9 hours and 50 minutes. On 4th almost near full moon can be seen to its south and repeats this performance on 31st. Actually, on both the occultation the moon will occult the planet.Saturn is in Pisces and rises as the Sun sets.This is one of the most beautiful objects in the sky. The moon passes south of Saturn on 7th early in the morning. Its rings are widening slowly and will continue to do so till 2002. If you are interested in astronomy then you should do your best to see its rings through a good telescope. There is an association of amateur astronomers in Pune called Jyotirvidya Parisanstha. They meet on every Sunday at Tilak Smarak Mandir on Tilak Road between 5.30 pm and 8.30 pm.By about two hours after the midnight, Mars will rise above the eastern horizon. On 6th, it can be seen close to Regulus (Magha) in Leo, the Lion. Notice the striking colour contrast between the planet and the star. If you are not an early riser but interested in astronomy switch on every possible alarm clock in your house for 15th, 16th and 17th. You can see the moon sliding past Regulus and Mars.Venus is almost gone this month. It will now be seen above the western horizon by early January 1999. Mercury can be spotted this month above the western horizon. It will be about 7 degrees south of thin crescent of Moon on 21st.The map given here is drawn to show the positions of stars which can be seen from Pune at about 8.30 p.m. on 15th of October. This map can be used in the first week of the month around 9.30 p.m. and at about 7.30 p.m. by the last week of the month. The size of the dots on the map represents the relative brightness of the stars. The bigger the dot, brighter the star.The names in capitals are the constellations and others are the names of the stars. In the text below, the names given in the brackets are Indian names of the stars and the Nakshatras.Cut and paste the map on a stiff sheet of cardboard and to read the map in the night, use a small torch covered with red gelatin or cellophone tape. Use the map within an hour or so of the time indicted above. Turn the map around so the edge marked with the direction you're facing is down. The stars above this horizon on the map match the stars you are facing. The map's centre is straight overhead. So a star halfway from the edge to the centre can be found about halfway from the horizontal to straight up.To learn to identify the constellations and stars identify one of the prominent constellations shown on the map. There after try to identify other stars making other constellations.
