A close-up view from the NASA/ESA Hubble Space Telescope of NGC 4755, the Jewel Box cluster. Several very bright, pale blue supergiant stars, a solitary ruby-red supergiant and a variety of other brilliantly colored stars are visible in the image, as well as many much fainter ones. This is the first image of an open galactic cluster with imaging extending from the far ultraviolet to the near-infrared. Credit: NASA/ESA and Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain)
