By P. Naik
The chart above shows the night sky over Shillong during the month of March 2012 at 7.00 p.m. Shillong being at 25.5o N,latitude we see mostly northern constellations.
The E-W line shows the celestial equator and the line cutting it shows the zodiac line or the sun’s apparent path. The capital letters indicate the name of constellations and the other letters indicate the prominent stars. Planet Jupiter and Venus are visible in the western horizon. Planet Mars is visible over sky all the night.
The prominent constellations visible are Eridanus,Cepheus , Leo, Canis minor, Cetus, Orion, Canis Major, Pisces, Puppis, Gemini, Taurus, Aries, Perseus, Andromeda, Cassiopeia, Ursa major, Ursa minor, Auriga,,Hydra and Cetus.
The constellation of the month is Canis Major. In Europe, Canis Major has been associated with dogs from early times.It contains the brightest star after the sun Sirius means scorching,since the summer heat occurred after Sirius heliaacial rising.
The ancient Greeks referred to such times in the summer as dog days, as only dogs would be mad to out in the heat,leading to the star being known as Dog star. Consequently , the constellation was named after it as a Big Dog.
The other history is that the most Important star in this constellation is a Canis Majoris, Sirius the Dog star, so named because it is the brightest component of Canis Major which, to the Egyptians, represented Anubis, the jakal-headed god.
Sirius rose just before the Sun when the Nile was about to begin its yearly flood, and therefore was of great importance in the Egyptian Calendar.
Sirius is a mag – 1:43 A1 type star less than 9 light years away and is the brightest star in the sky.
It is accompanied by a faint companion orbiting 2.9 × 199 km away in 49.9 years (mag 9.1). Sirius B was the first white dwarf to be discovered. Canis Major contains four other stars brighter than mag 2.5 and also M41, an open cluster lying 1300 light years away.
Many of the stars are in fact intrinsically brighter than the Sirius but at very great distances, rendering them visually fainter than this nearby star.
The special event during the month is planet Mars is in opposition on 3rd March and peaks in brightness for the year during the month.
