![]() The Cave Nebula (C9, Sh2-155) is a diffuse nebula approximately 2,400 light years away in Cepheus. The cluster has an apparent magnitude of 9.5 and an apparent size of 7 arcminutes. It lies in the region between Segin (Epsilon Cassiopeiae) and Gamma Cassiopeiae, the leftmost and central stars of Cassiopeia’s W. NGC 559 (C8) is an open star cluster about 7,200 light years away in Cassiopeia. NGC 2403, image: Adam Block/Mount Lemmon Sk圜enter/University of Arizona (CC BY-SA 4.0) NGC 559 (Caldwell 8) It is an outlying member of the M81 Group. NGC 2403 occupies an area of 21.9 by 12.3 arcminutes. It has an apparent magnitude of 8.9 and appears similar to the Triangulum Galaxy (Messier 33). NGC 2403 (C7) is an intermediate spiral galaxy located approximately 9.65 million light years away in the constellation Camelopardalis. Image: Hubble Space Telescope NGC 2403 (Caldwell 7) Of course, gazing into the Cat’s Eye, astronomers may well be seeing the fate of our sun, destined to enter its own planetary nebula phase of evolution… in about 5 billion years. Compared to well-known Hubble pictures, the alternative processing strives to sharpen and improve the visibility of details in light and dark areas of the nebula and also applies a more complex color palette. Here, Hubble Space Telescope archival image data have been reprocessed to create another look at the cosmic cat’s eye. But the formation of the beautiful, more complex inner structures is not well understood. ![]() This nebula’s central star may have produced the simple, outer pattern of dusty concentric shells by shrugging off outer layers in a series of regular convulsions. The Cat’s Eye (NGC 6543) represents a brief, yet glorious, phase in the life of a sun-like star. Staring across interstellar space, the alluring Cat’s Eye Nebula lies 3,000 light-years from Earth. It lies near Kappa Draconis, roughly halfway between Kochab in Ursa Minor and Dubhe in Ursa Major. However, it does not appear close to these galaxies in the sky. The galaxy is a member of the M81 Group, which also contains Bode’s Galaxy (Messier 81) and the Cigar Galaxy (Messier 82). It has an apparent magnitude of 10.5 and an apparent size of 21.9 by 7.2 arcminutes. NGC 4236 (C3) is a barred spiral galaxy about 11.7 million light years away in Draco. The central star has the spectrum of a carbon-rich Wolf-Rayet star. It has an apparent magnitude of 10.7 and an apparent size of 38 by 35 arcseconds. The Bow-Tie Nebula (C2) is a planetary nebula approximately 3,500 light years away in Cepheus. It is one of the oldest open clusters known, with an estimated age of about 6.8 billion years. The cluster has an apparent magnitude of 10.0 and an apparent size of 15 arcminutes. It appears less than 5 degrees from the north celestial pole. NGC 188 (C1) is an open cluster in Cepheus. However, half-marathons are popular with astronomy clubs, since at least half of the objects are visible from most locations. Unlike the Messier objects, these objects cannot be seen in the same night from a single location. The Caldwell catalogue contains 35 galaxies, 28 open clusters, 18 globular clusters, 12 bright nebulae, one dark nebula, and two supernova remnants. They are listed by declination, starting with the northernmost open cluster NGC 188 in Cepheus and ending with the planetary nebula NGC 3195 in Chamaeleon in the far southern sky. He used his other surname – Caldwell – to name the catalogue because “Moore” has the same initial as “Messier.”Ĭaldwell objects are designated with a “C” and the catalogue number. His list was published in Sky & Telescope in December 1995. Moore listed 109 objects to roughly match the number of objects listed in the Messier catalogue (110). Some of these objects are visible to the unaided eye and some can be seen in binoculars. Sir Patrick Moore compiled the catalogue to provide amateur astronomers with a list of deep sky objects that can be easily observed in small and medium telescopes. ![]() Unlike the Messier catalogue, the Caldwell list includes objects all across the sky and not only those visible from mid-northern latitudes. ![]() Compiled by the English amateur astronomer Sir Patrick Moore in the 1980s, the catalogue is a popular guide for visual astronomy and serves as a supplement to Charles Messier’s list. The Caldwell catalogue is a list of 109 bright deep sky objects that can be observed in amateur telescopes, but are not included in the Messier catalogue. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |