“U Geminorum star”的意思、由来-百科全书

U Geminorum star

astronomy

any of a class of irregular variable stars that display sudden increases in brightness so great that they are sometimes called dwarf novae. Some have been observed to brighten by as much as 5 magnitudes (100 times) in a period of hours. The prototype star, U Geminorum, brightens by as much as 4 magnitudes (about 40 times) in a few days, declining again to normal brightness in two or three weeks. U Geminorum was the first of the class to be discovered, in 1855, by the English astronomer John Russell Hind. Fewer than 200 U Geminorum stars are known; sometimes they are called SS Cygni stars, after the brightest known member of the class. All are binaries with periods of less than a day.

词条	U Geminorum star
释义	U Geminorum star astronomy any of a class of irregular variable stars that display sudden increases in brightness so great that they are sometimes called dwarf novae. Some have been observed to brighten by as much as 5 magnitudes (100 times) in a period of hours. The prototype star, U Geminorum, brightens by as much as 4 magnitudes (about 40 times) in a few days, declining again to normal brightness in two or three weeks. U Geminorum was the first of the class to be discovered, in 1855, by the English astronomer John Russell Hind. Fewer than 200 U Geminorum stars are known; sometimes they are called SS Cygni stars, after the brightest known member of the class. All are binaries with periods of less than a day.
随便看	Manifesto of Futurism manifold Manihiki Atoll Manila Manila Bay Manila Bay, Battle of Manila galleon Manilius, Marcus Manin, Daniele Maning, Frederick maniple Manipur manipuri Manisa Manises ware Man, Isle of Manistee Manitoba Manitoba, flag of Manitoba, Lake manitou Manitoulin Islands Manitowoc Maniu, Iuliu Manius Curius Dentatus