- Messier 53 (also known as M53 or NGC 5024) is a globular cluster in the Coma Berenices constellation. It was discovered by Johann Elert Bode in 1775. M53 is one of the more outlying globular clusters, being about 60,000 light-years (18.4 kpc) light-years away from the Galactic Center, and almost the same distance (about 58,000 light-years (17.9 kpc)) from the Solar System. The cluster has a core radius (rc) of 2.18 pc, a half-light radius (rh) of 5.84 pc, and a tidal radius (rtr) of 239.9 pc.
- Cebalrai (stars.astro.illinois.edu)
CEBALRAI (Beta Ophiuchi). At the northern tip of Ophiuchus, the Serpent Bearer, lies Rasalhague, the bright Alpha star. Helping to form the huge rough pentagon that makes the classic figure is Cebalrai, at the pentagon’s northeastern corner, its position and bright third magnitude status (2.77) causing Bayer to call it “Beta.”