- Messier 53 (Wikipedia)
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.
- Octagon (Wikipedia)
In geometry, an octagon (from the Greek á˝ÎşĎÎŹÎłĎνον oktĂĄgĹnon, “eight angles”) is an eight-sided polygon or 8-gon.
