C91

NGC 3532 is one of the brightest and richest open clusters in the sky, located in Carina about 1,321 light-years away. Spanning 55 arcminutes, it contains about 150 stars brighter than magnitude 12 and over 400 confirmed members. At magnitude 3.0, it is easily visible to the naked eye.

A stunning cluster in binoculars and wide-field telescopes. The large angular size means low power is essential. Many colorful stars including orange giants contrast with blue-white members. John Herschel called it the most beautiful object in the sky. Best from southern latitudes in late winter and spring.

Discovered by Nicolas Louis de Lacaille in 1751 from South Africa. John Herschel described it glowingly during his southern sky survey from the Cape of Good Hope in the 1830s. It was the first target observed by the Hubble Space Telescope in 1990 for calibration.