By Prashant Naik
The chart above shows the night sky over Shillong during the month of April 2013 at 8.00 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 Saturn and Jupiter are clearly visible in the eastern and the western side.
The prominent constellations visible are, Leo, Orion,Canis major,Canis minor, Virgo, , Bootes, Perseus Taurus, Puppis, Gemini, Auriga,Hercules, Ursa major, Ursa minor, Hydra, Corvus , Cepheus,Centaurus and Vela.
The constellation of the month is Leo. Leo is one of the oldest constellations and was recognized by many ancient civilizations, including those in Babylonia, Egypt and Greece. It was then closer to the position of the sun at summer solstice. It is one of the members of the zodiac.
Leo has been represented as a lion by numerous civilizations for thousands of years. One explanation is that the Sun was among its stars in Midsummer, and during this time the lions of the Egyptian desert left their accustomed haunts for the banks of the Nile, where they could find relief from the heat in the waters of the inundation.
Pliny wrote that the Egyptians worshipped the stars of Leo because the rise of their great river was coincident with the Sun’s entrance among them. Distinct reference is made to Leo in an inscription of the walls of the Ramesseum at Thebes, which, like the Nile temples generally, was adorned with the animal’s bristles, while on the planisphere ofDendera its figure is shown standing on an outstretched serpent. The Egyptian stellar Lion, however, comprised only a part of the modern constellation, and in the earliest records some of its stars were shown as a knife, whereas they now are as a sickle. The Persians called Leo Ser or Shir; the Turks, Artan; the Syrians, Aryo; the Jewish, Arye; the Indians, Simha ; and the Babylonians, Aru — all meaning a lion. In Euphratean astronomy it was additionally known as Gisbar-namru-sa-pan, variously translated, but by Bertin, as the Shining Disc which precedes Bel, “Bel” being our Ursa Major, or in some way intimately connected therewith.
In Greek mythology, it was identified as the Nemean Lion which was killed by Hercules during one of his twelve labours, and subsequently put into the sky.
The Roman poet Ovid called it Her-culeus Leo and Violentus Leo. Bacchi Sidus (Star of Bacchus) was another of its titles, the god Bacchus always being identified with this animal. However, Manilius called it Jovis et Junonis Sidus (Star of Jupiter and Juno).
Early Hindu astronomers knew it as Asleha and as Sinha, the Tamil Sim-ham but later, influenced by Greece and Rome, as Leya or Loin, from the word Leo, as the Romans commonly called it.
The most interesting objects in the constellation are Alpha, Regulus, which is double (mags 1ÿ36 and 7ÿ7) of type B7, and lying at distance of 84, light years.
Upsilon, Algieba, is a spectacular double, appearing yellow and green.
The combined magnitude is 1ÿ99 and the pair lies at a distance of nearly 200 light years.
Beta Denebola, is a mag 2ÿ14 A3 type, just 43 light years away.
One of the brightest intrinsically, in the constellation is Epsilon, Asad Australis, a mag 2ÿ99, G0 type star which is 340 light years away. As would be expected from its close proximity to Coma Berenices and Virgo, Leo contains many external galaxies visible above the galactic plane.