![]() Caption:NGC 104, 47 Tucanae, in the constellation Tucana. One of the nearest globular clusters known, at a distance of 16,000 light years. This group of older stars has a diameter of 210 light years. Copyright: Credit: National Optical Astronomy Observatories |
![]() Caption:NGC 6522 and NGC 6528, two globular star clusters seen through the dense starfield towards the center of our galaxy in the constellation Sagittarius. Kitt Peak National Observatory 4-meter Mayall telescope photo. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: M3, NGC 5272, a globular star cluster in the constellation Canes Venatici. This cluster contains more known variable stars than any other in this orbit around our Milky Way galaxy. Over 50,000 stars are contained in this 10 billion year-old globular cluster, which has a diameter of 280 light years and is 31,000 light years away from Earth. Kitt Peak National Observatory 4-meter Mayall telescope photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: M92, NGC 6341, globular star cluster in the constellation Hercules. This globular cluster has a diameter of 200 light years and is 28,000 light years distant. Kitt Peak National Observatory 4-meter Mayall telescope photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: M15, NGC 7078, a globular cluster in the constellation Pegasus. This cluster is unusual in that it contains a small planetary nebula (K 648) in the north-east side. M15 is also a strong x-ray source. It is located 34,000 light years (10.5 kilo parsecs) away and has a diameter of 130 light years. Kitt Peak National Observatory 4-meter Mayall telescope photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: M5, NGC 5904, a globular star cluster in the constellation Serpens. This large cluster is among the most massive in orbit about our galaxy, containing mass equivalent to 2 million Suns. The globular cluster is also ancient, believed to be 13 billion years old. It is located at a distance of 26,000 light years. Kitt Peak National Observatory photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: 47 Tucanae, NGC 104, in the constellation Tucana - one of the nearest globular clusters known, at a distance of 16,000 light years. The group of older stars has a diameter of 210 light years and a mass approximately one million times that of our Sun. Cerro Tololo Inter-American Observatory 4-meter photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: NGC 5139, Omega Centauri, globular star cluster in the constellation Centaurus. Visible with the naked eye to observers in the southern hemisphere and in the south half of the northern hemisphere, 5139 is located at a distance of 17,000 light years and contains over one million stars within its 150 light year diameter. Near the center of the globular cluster, stars may be about one-tenth of a light year apart (as compared to 4.3 light years distance between our Sun and the nearest star, Proxima Centauri). Cerro Tololo Inter-American Observatory 4-meter photograph. Copyright: Credit:National Optical Astronomy Observatories |
![]() Caption: 47 Tucanae is magnificent naked-eye globular cluster. These ancient cities of stars contain several million stars, as many as some minor galaxies, and the central region is very crowded. This crowding leads to occasional stellar encounters and it is in 47 Tuc that rapidly-spinning pulsars have recently been discovered by radio astronomers. Though the light of globular clusters is dominated by so-called "red" giant stars, their color is no redder than a domestic tungsten lamp, so the true color of 47 Tuc is closer to the pale yellow reproduced here. Copyright:(c) 1992 Anglo-Australian Telescope Board, photograph by David Malin Credit: |
![]() Caption: Very few color pictures of globular clusters exist because they are not generally regarded as especially colorful. However, many astronomers have invested much time and effort in measuring the colors of stars in these ancient stellar gatherings and their color- magnitude diagrams, which compare brightness and color, show a considerable range of hues in the stars. In this picture, made from a series of two minute AAT exposures, the colors of the brighter stars are clearly seen, especially the large number of blue, "horizontal branch" stars. These stars affect the overall color of the cluster significantly, making its integrated light slightly bluer than that of the Sun. Copyright:(c) 1992 Anglo-Australian Telescope Board, photograph by David Malin Credit: |
![]() Caption: Right: A region 1.4 light years across in the globular star cluster NGC 6347, imaged by the Hubble Space Telescope, shows that faint red dwarf stars are not abundant. It appears that there are no stars with masses less than one-fifth of the Sun's. Left: A ground-based view of the whole cluster, which is 7,200 light years away and in the constellation Ara. Copyright: Credit:F. Paresce and NASA |
![]() Caption:An ultraviolet image of the central part of the globular cluster Omega Centauri made with the Ultraviolet Imaging Telescope on board the orbiting observatory Astro 1. Copyright: Credit:NASA |