Diferència entre revisions de la pàgina «Estrella múltiple»

(HD 188753)
 
*[[HD 188753]] és una sistema estel·lar triple físic localitzat aproximadament a 149 [[any-llum|anys-llum]] de la [[Terra]] a la [[constel·lació]] de [[Cygnus]]. El sistema està componst de HD 188753A, una [[nana groga]]; HD 188753B, una [[nana taronja]]; i HD 188753C, una [[nana vermella]]. B i C orbiten una voltant l'altre cada 156 dies, i , com a grup, orbiten A cada 25,7 dies.
 
==Examples==
 
* [[HR 3617]] is a multiple star with three component stars, HR 3617A, HR 3617B, and HR 3617C. A and B form a physical [[binary star]], while C is optical.
* [[Alpha Centauri]] is a triple star composed of a main binary [[yellow dwarf]] pair ([[Alpha Centauri A]] and [[Alpha Centauri B]]), and an outlying [[red dwarf]], [[Proxima Centauri]]. A and B are a physical [[binary star]], with an eccentric [[orbit]] in which A and B can be as close as 11 [[astronomical unit|AU]] or as far away as 36 AU. Proxima is much further away (~15,000 AU) from A and B than they are to each other. Although this distance is still small compared to other interstellar distances, it is debatable whether Proxima is gravitationally bound to A and B.<ref>[http://adsabs.harvard.edu/abs/2006AJ....132.1995W Are Proxima and α Centauri Gravitationally Bound?], Jeremy G. Wertheimer, Gregory Laughlin, ''Astronomical Journal'' '''132''', #5 (November 2006), pp. 1995&ndash;1997.</ref>
* [[HD 188753]] is a physical triple star system located approximately 149 [[light year]]s away from [[Earth]] in the [[constellation]] [[Cygnus]]. The system is composed of HD 188753A, a [[yellow dwarf]]; HD 188753B, an [[orange dwarf]]; and HD 188753C, a [[red dwarf]]. B and C orbit each other every 156 days, and, as a group, orbit A every 25.7 years.
* [[Polaris]], the north star, is a triple star system in which the closer companion star is extremely close to the main star&mdash;so close that it was only known from its gravitational tug on Polaris A until it was photographed by the [[Hubble Space Telescope]] in 2006.
*[[Polaris]], l'estrella del nord. És un sistema estel·lar triple en el que la companya més pròxima a l'estrella principal està molt aprop de la principal&mdash;tan pròxima que només és coneguda per la seva estirada gravitacional sobre Polaris A des de que fou fotografiada per el [[Telescopi Espacial Hubble]] en el 2006.
 
 
[[Categoria:Estrelles]]
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