47 Tucanae

47 Tucanae (also known as NGC 104 ) is apparent as a small patch of fog after Omega Centauri the second brightest globular cluster of heaven and even with the naked eye.

Discovery and designation

The designation 47 Tucanae is because the cluster was initially viewed as a star because of its compact appearance and large apparent brightness and named accordingly. Further investigated initially has him in 1751 by the French astronomer Nicolas Louis de Lacaille.

Location and characteristics

47 Tucanae is right next to the Small Magellanic Cloud, to which he does not belong, however. Visible it is only from the southern hemisphere. With an apparent diameter of 30 ' it reaches a brightness of 4.9 mag. Within about 120 light years in diameter of the star cluster hosts several million stars, including several red giants. In the center of the pile, the stars are very tightly packed and have sometimes less than 0.1 light-years apart.

Long-term observations with the Fermi Gamma - ray Space Telescope have 47 Tucanae as a weak source of gamma radiation seen, which is probably generated by Millisekundenpulsare.