guide to night sky for mid northern latitudes

(Note: The names of the constellations are given in bold and the names in italics are the names of heavenly bodies in Indian astronomy. For better understanding take a print out of the map.)

We again start our observations from the western direction. Face west and hold the map so that 'West' marked on it is in the direction of your feet and 'East' is up (it will be read upside down) and now turn a bit to your right. You should be able to see three bright stars making a big triangle. The base of this triangle is almost parallel to the horizon. We talked about this constellation last month. Therefore, to revise it quickly the star at the apex of the triangle is Deneb in Cygnus, the Swan [Hans]. The one to the left is Altair [Shravan] in Aquila, the Eagle [Garuda] and the one to the left is Vega [Abhijit], in Lyra, the Lyre [Swaramandal].  

Right overhead is the Great Square of Pegasus, the Winged Horse [Maha-ashwa]. Its two leading stars (to the west) make the 25th Nakshartra; Purva Bhadrapada and the other two make the 26th Nakshatra Uttara Bhadrapada. Purva and Uttara are in the sense of earlier and later.
Facing north look slightly to the east. There is a celestial 'M' whose left leg is pulled a little too much to the east. This constellation is Cassiopeia [Sharmishatha]. From west to east you can count five bright stars. Take 1st and 3rd star and join the two by an imaginary line. If you take perpendicular bisector of this line and extend it to the northern direction then the line goes through the pole stars, the Polaris. The other constellation that helps us to find the pole star, as you might know is Ursa Major, the Great Bear [Sapta rishi].

If you now turn to east you will be treated with three bright constellations. Auriga, the Charioteer [Sarathi] is well above the northwestern horizon. Orion, the Hunter [Mruga] is just rising and between the two, but well have the horizon we have Taurus, the Bull [Vrishabha].

Capella [Brahamha Rhudaya] is the brightest star in Auriga. Under a clear dark night you will be able to make out its yellowish colour. It is about 45 light years from us. To the right and a bit above you should be able to see the head of the Taurus. The brightest star is his constellation is Aldebaran [Rohini]. Aldebaran is about 65 light years from us. In the same direction is a scattered group of stars, a cluster named Hyades. This group of stars is twice as far as Aldebaran. Of course, before we know the distances Aldebaran was (and for the viewing pleasure still is) the member of Hyades cluster. Rohini is 4th Nakshatra.
Further up above you can see another cluster of stars, Pleiades (Kruttika, 3rd Nakshatra). Use a pair of binoculars to look at this magnificent cluster. This is, however, not a great sight at higher magnification. This group is surrounded by thin dust, which shows up in long exposure photographs.


  One of the brightest stars in the southern direction is Acherner [agra-nad] in Eridanus, the River [Yamuna]. The name Acherner comes from 'Al Ahir al Nahr' or 'Akhir an-Nahr' means the End of the River. We call it Agra-nad or debaucher of river, Yamuna. Eridanus is now completely above the horizon. It stars (or ends) near Orion, which is now, well above the horizon.
It is said that to know Orion is to know astronomy. This constellation has almost every type of heavenly objects. It has stars of all the classification, it has dark and bright clouds of gas and dust. All the planets pass through northern end of this constellation. It is also the beginners and seasoned astronomers. It is available all through the night when the skies are clear for the longest time that is during the winters. Next month Orion will be well above the horizon and we will discuss this constellation in detail. But for this month make your self-familiar with is constellation.
The basic figure of Orion comes from the three bright lines on one line that is boxed inside four stars. It is a bit difficult to imagine Orion as giant human figure from latitudes below 30 degrees. In order to imagine this figure you will have to tilt your head to left. The three stars on a line make the belt of the Hunter. The star at the left bottom corner of the box is called Betelgeuse [Kakshi] is the right knee of the giant. This star is what astronomers call red super giant. The star is so big that if it were placed where the Sun is then it would engulf all the solar system up the orbit of Mars. This star is rather a cooler one. Temperature at its surface is about 3500 degrees. The surface temperature of the sun is about 6500. If that is not enough then look at the star at the other end of the box. The bright sparkling star is Rigel [Rajanya], which has surface temperature twice that of the sun and that is 11000 degrees. It is the 7th brightest stars in the night sky.
To the right of Betelgeuse and a bit above you should be able to see a group of three stars. It is head of Orion or Mruga Shirsha the 5th Nakshatra. If you look at the right side of the three-stars-on-a-line you will notice a big chain of stars. Here lies the famous Great Orion Nebula. Scan this area of the sky with a pair of binoculars.
Almost overhead is Cetus, the Whale [Timingal]. If you look at the map carefully you will find that a star is joining two polygons. This star is Mira, the Wonderful. These days you can see this star but soon it will start fading away and you will not be able to see it at all. This star is a long period eruptive variable. This stars is normally too faint to be seen even in a small telescope. But every after 330 days or so this star brightens up.

The material here can be used freely.
It is, however, expected that the source may be acknowledged.

Credit :
Inter-University Centre for Astronomy and Astrophysics, Pune.)

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Site created on June 10, 2007
Updated on June 10, 2007