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- BY_Draconis abstract "BY Draconis is a multi-star system in the constellation Draco. It consists of at least three components. Components A and B form a close binary star system with a short orbital period of only 5.98 days. These may be pre-main sequence objects that are still in the process of collapsing. Their individual spectroscopic classifications are dK5e and dK7e. They form the prototype of a class of variable stars known as BY Draconis variables.The third component (C) is, by comparison, widely separated from the A-B pair by an angular distance of 17 arcseconds, which corresponds to 260 AU at the estimated distance of this star system—where an AU is the average distance from the Earth to the Sun. Component C is an M5 class red dwarf star. There may be a fourth component to the system, orbiting with a 114 day period, but this has not been visually confirmed.The variability of BY Draconis is caused by activity in the stellar photosphere called starspots, which are comparable to sunspots on the Sun, in combination with rapid rotation that changes the viewing angle of the activity relative to the observer. This variation has an average periodicity of 3.8285 days, but the brightness also changes over the course of several years—depending on the level of surface activity. Most observers believe that the primary star (A) is responsible for the variability as the secondary produces only a third of the total luminosity from the system. However, the spots may occur on both stars. Unlike the Sun, these spots may occur in the polar regions of the stars.".
- BY_Draconis wikiPageExternalLink BY_Draconis_star.html.
- BY_Draconis wikiPageID "16996815".
- BY_Draconis wikiPageRevisionID "603321332".
- BY_Draconis appmagV "8.07".
- BY_Draconis axis "4.4".
- BY_Draconis bV "+1.19".
- BY_Draconis class "K6Ve".
- BY_Draconis constell Draco_(constellation).
- BY_Draconis eccentricity "0.298".
- BY_Draconis epoch "J2000".
- BY_Draconis hasPhotoCollection BY_Draconis.
- BY_Draconis inclination "151.8".
- BY_Draconis name "BY Dra B".
- BY_Draconis pError "0.73".
- BY_Draconis parallax "60.9".
- BY_Draconis period "0.01637".
- BY_Draconis propMoDec "−324.90".
- BY_Draconis propMoRa "186.62".
- BY_Draconis radialV "−27±5".
- BY_Draconis uB "+0.99".
- BY_Draconis variable BY_Draconis_variable.
- BY_Draconis subject Category:BY_Draconis_variables.
- BY_Draconis subject Category:Draco_(constellation).
- BY_Draconis subject Category:Henry_Draper_Catalogue_objects.
- BY_Draconis subject Category:K-type_main-sequence_stars.
- BY_Draconis subject Category:Objects_named_with_variable_star_designations.
- BY_Draconis type BYDraconisVariables.
- BY_Draconis type PhysicalEntity100001930.
- BY_Draconis type Thing100002452.
- BY_Draconis type Variable109468959.
- BY_Draconis type CelestialBody.
- BY_Draconis type Star.
- BY_Draconis type PhysicalBody.
- BY_Draconis comment "BY Draconis is a multi-star system in the constellation Draco. It consists of at least three components. Components A and B form a close binary star system with a short orbital period of only 5.98 days. These may be pre-main sequence objects that are still in the process of collapsing. Their individual spectroscopic classifications are dK5e and dK7e.".
- BY_Draconis label "BY Draconis".
- BY_Draconis label "BY Draconis".
- BY_Draconis label "BY Дракона".
- BY_Draconis label "りゅう座BY星".
- BY_Draconis label "天龍座BY".
- BY_Draconis sameAs BY_Draconis.
- BY_Draconis sameAs りゅう座BY星.
- BY_Draconis sameAs m.0414zwc.
- BY_Draconis sameAs Q2660608.
- BY_Draconis sameAs Q2660608.
- BY_Draconis sameAs BY_Draconis.
- BY_Draconis wasDerivedFrom BY_Draconis?oldid=603321332.
- BY_Draconis isPrimaryTopicOf BY_Draconis.
- BY_Draconis name "BY Draconis AB".