Space Catalogue Facts

Astronomers list the stars in each constellation according to their brightness, using the Greek alphabet. So the brightest star in the constellation of Pegasus is Alpha Pegasi.
The first catalogue of non-stellar objects (things other than stars, such as nebulae) was made by astronomer Charles Messier (1730-1817). Objects were named M (for Messier) plus a number. M1 is the Crab nebula.
Messier published a list of 103 objects in 1781, and by 1908 his catalogue had grown to 15,000 entries.
Many of the objects originally listed by Messier as nebulae are now known to be galaxies.
Today the standard list of non-stellar objects is the New General Catalogue of nebulae and star clusters (NGC). First published in 1888, this soon ran to over 13,000 entries.
Many objects are in both the Messier and the NGC and therefore have two numbers.
The Andromeda galaxy is M31 and NGC224.
Radio sources are listed in similar catalogues, such as Cambridge University’s 3C catalogue.
The first quasar to be discovered was 3c 48.
Many pulsars are now listed according to their position by right ascension and declination.

This entry is filed under Interesting Facts.