NGC 4755, the Jewel Box open cluster
Date created: 1983-11-16
This famous group of young bright stars is an open cluster some 7800 light years from the Sun. It was named the Jewel Box from its description by Sir John Herschel as 'a casket of variously coloured precious stones', which refers to its appearance in the telescope. The bright orange star is kappa Crucis, and it contrasts strongly against its predominantly blue, hot companions. Kappa Cru is a very large, (hence very luminous) quite young star in its red supergiant stage, which paradoxically indicates that its life is drawing to a close. The cluster looks like a star to the unaided eye and appears close to Mimosa, the eastern-most star of the Southern Cross
, so is only visible from southern latitudes. Photograph made from plates taken in February 1991.
Top left is NE. Image width is about 11.5 arc min.
Credit: David Malin
© Australian Astronomical Observatory