- One of the dozen new constellations introduced at the end of the 16th century from observations of the southern sky by the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman. Apus represents a fabulous bird of paradise, as found in New Guinea, but it is a disappointing tribute to such an exotic creature, its brightest stars being of only 4th magnitude.
- Messier 10 (Wikipedia)
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.