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SEXTANS
The Sextant
Sextans - Alexander Jamieson - 1822
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Sextans was named by astronomer Johannes Hevelius in the 17th century after the sextans uraniae, otherwise known as the sextant. At that time the sextant was an absolutely essential tool for astronomers. It was also an essential tool for sailors. It measured the angle of celestial objects above the horizon, which helped determine the exact location of a ship at sea. Below are examples of sextants, showing their familiar triangular shape and curved base.
There is not much to observe in the constellation Sextans. The brightest star, Alpha Sextanius, has a magnitude of only 4.49. But on a nice dark night, if you look just underneath Leo, you will sea a group of dim stars that really do form the shape of an a sextans.
There is one notable object in the constellation, NGC 3115, one of two galaxies known as the Spindle Galaxy. It is a bright lenticular galaxy seen almost edge on, located about 32 million light years away. At the centre of the galaxy is a supermassive black hole, approximately one billion times as massive as our Sun. Photo below by NASA's Chandra Space Telescope.
So far five extrasolar planets have been discovered in Sextans orbiting four stars. Unfortunately these stars are all beyond naked eye visibility, and the planets are all the size of Jupiter or larger. For more information see NASA's planet quest.
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