- Messier 10 or M10 (also designated NGC 6254) is a globular cluster of stars in the equatorial constellation of Ophiuchus. The object was discovered by the French astronomer Charles Messier on May 29, 1764, who cataloged it as number 10 in his catalogue and described it as a “nebula without stars”. In 1774, German astronomer Johann Elert Bode likewise called it a “nebulous patch without stars; very pale”. Using larger instrumentation, German-born astronomer William Herschel was able to resolve the cluster into its individual members. He described it as a “beautiful cluster of extremely compressed stars”. William Parsons, 3rd Earl of Rosse thought he could distinguish a dark lane through part of the cluster. The first to estimate the distance to the cluster was Harlow Shapley, although his derivation of 33,000 light years was much further than the modern value.
- Ophiuchus (Wikipedia)
Ophiuchus (/ˌɒfiˈjuːkəs/) is a large constellation straddling the celestial equator. Its name comes from the Ancient Greek ὀφιοῦχος (ophioûkhos), meaning “serpent-bearer”, and it is commonly represented as a man grasping a snake. The serpent is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. An old alternative name for the constellation was Serpentarius (/ˌsɜːrpənˈtɛəriəs/).