Matches in DBpedia 2016-04 for { <http://dbpedia.org/resource/W_Ursae_Majoris> ?p ?o }
- W_Ursae_Majoris abstract "W Ursae Majoris (W UMa) is the variable star designation for a binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of about 7.9, which is too faint to be seen with the naked eye. However, it can be viewed with a small telescope. Parallax measurements place it at a distance of roughly 170 light years (53 parsecs) from Earth.In 1903, the luminosity of this system was found to vary by the German astronomers Gustav Müller and Paul Kempf. It has since become the prototype and eponym for a class of variable stars called W Ursae Majoris variables. This system consists of a pair of stars in a tight, circular orbit with a period of 0.3336 days, or eight hours and 23 seconds. During every orbital cycle, each star eclipses the other, resulting in a decrease in magnitude. The maximum magnitude of the pair is 7.75. During the eclipse of the primary, the net magnitude drops by 0.73, while the eclipse of the secondary causes a magnitude decrease of 0.68. Unlike normal eclipsing binaries, the contact nature makes it impossible to precisely tell when an eclipse of one component by the other starts or ends.The two stars in W Ursae Majoris are so close together that their outer envelopes are in direct contact. Hence they have the same stellar classification of F8Vp, which matches the spectrum of a main-sequence star that is generating energy through the nuclear fusion of hydrogen. However, the primary component has a larger mass and radius than the secondary, with 1.19 times the Sun's mass and 1.08 times the Sun's radius. The secondary has 0.57 solar masses and 0.78 solar radii.The orbital period of the system has changed since 1903, which may be the result of mass transfer or the braking effects of magnetic fields. Star spots have been observed on the surface of the stars and strong X-ray emissions have been detected, indicating a high level of magnetic activity that is common to W Uma variables. This magnetic activity may play a role in regulating the timing and magnitude of mass transfer occurs.W Ursae Majoris has a 12th magnitude companion star with the designation ADS 7494B. They may be moving together through space.".
- W_Ursae_Majoris thumbnail Ursa_Major_constellation_map.svg?width=300.
- W_Ursae_Majoris wikiPageExternalLink wuma.shtml.
- W_Ursae_Majoris wikiPageID "279836".
- W_Ursae_Majoris wikiPageLength "8757".
- W_Ursae_Majoris wikiPageOutDegree "35".
- W_Ursae_Majoris wikiPageRevisionID "682265271".
- W_Ursae_Majoris wikiPageWikiLink Apparent_magnitude.
- W_Ursae_Majoris wikiPageWikiLink Binary_star.
- W_Ursae_Majoris wikiPageWikiLink Category:F-type_main-sequence_stars.
- W_Ursae_Majoris wikiPageWikiLink Category:Henry_Draper_Catalogue_objects.
- W_Ursae_Majoris wikiPageWikiLink Category:Objects_named_with_variable_star_designations.
- W_Ursae_Majoris wikiPageWikiLink Category:Ursa_Major_(constellation).
- W_Ursae_Majoris wikiPageWikiLink Category:W_Ursae_Majoris_variables.
- W_Ursae_Majoris wikiPageWikiLink Durchmusterung.
- W_Ursae_Majoris wikiPageWikiLink Earth.
- W_Ursae_Majoris wikiPageWikiLink Eclipse.
- W_Ursae_Majoris wikiPageWikiLink Gustav_Müller.
- W_Ursae_Majoris wikiPageWikiLink Henry_Draper_Catalogue.
- W_Ursae_Majoris wikiPageWikiLink Hipparcos.
- W_Ursae_Majoris wikiPageWikiLink Light-year.
- W_Ursae_Majoris wikiPageWikiLink Main_sequence.
- W_Ursae_Majoris wikiPageWikiLink Nuclear_fusion.
- W_Ursae_Majoris wikiPageWikiLink Orbital_period.
- W_Ursae_Majoris wikiPageWikiLink Parallax.
- W_Ursae_Majoris wikiPageWikiLink Parsec.
- W_Ursae_Majoris wikiPageWikiLink Paul_Kempf.
- W_Ursae_Majoris wikiPageWikiLink Smithsonian_Astrophysical_Observatory_Star_Catalog.
- W_Ursae_Majoris wikiPageWikiLink Solar_mass.
- W_Ursae_Majoris wikiPageWikiLink Solar_radius.
- W_Ursae_Majoris wikiPageWikiLink Spectrum.
- W_Ursae_Majoris wikiPageWikiLink Stellar_classification.
- W_Ursae_Majoris wikiPageWikiLink Stellar_magnetic_field.
- W_Ursae_Majoris wikiPageWikiLink Ursa_Major.
- W_Ursae_Majoris wikiPageWikiLink Variable_star.
- W_Ursae_Majoris wikiPageWikiLink Variable_star_designation.
- W_Ursae_Majoris wikiPageWikiLink W_Ursae_Majoris_variable.
- W_Ursae_Majoris wikiPageWikiLink Wikt:eponym.
- W_Ursae_Majoris wikiPageWikiLinkText "W UMa".
- W_Ursae_Majoris wikiPageWikiLinkText "W Uma variable".
- W_Ursae_Majoris wikiPageWikiLinkText "W Ursae Majoris".
- W_Ursae_Majoris appmagV "7.9".
- W_Ursae_Majoris bV "+0.66".
- W_Ursae_Majoris class "F8Vp + F8Vp".
- W_Ursae_Majoris constell Ursa_Major.
- W_Ursae_Majoris epoch "J2000".
- W_Ursae_Majoris inclination "86".
- W_Ursae_Majoris mass "1.19".
- W_Ursae_Majoris pError "1.47".
- W_Ursae_Majoris parallax "18.72".
- W_Ursae_Majoris periodUnitless "28823.04".
- W_Ursae_Majoris propMoDec "–27.30".
- W_Ursae_Majoris propMoRa "+15.47".
- W_Ursae_Majoris radialV "-46".
- W_Ursae_Majoris radius "1.084".
- W_Ursae_Majoris rotationalVelocity "144.4".
- W_Ursae_Majoris simbad "**+ES+1825AB".
- W_Ursae_Majoris simbad "BD%2b56+1400B".
- W_Ursae_Majoris simbad "W+UMa".
- W_Ursae_Majoris sn "A".
- W_Ursae_Majoris sn "B".
- W_Ursae_Majoris sn "The system".
- W_Ursae_Majoris uB "+0.08".
- W_Ursae_Majoris variable W_Ursae_Majoris_variable.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Citation_needed.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Location_map.
- W_Ursae_Majoris wikiPageUsesTemplate Template:RA.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Reflist.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Solar_radius.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_astrometry.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_begin.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_catalog.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_character.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_detail.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_end.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_image.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_observe.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_orbit.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Starbox_reference.
- W_Ursae_Majoris wikiPageUsesTemplate Template:Stars_of_Ursa_Major.
- W_Ursae_Majoris subject Category:F-type_main-sequence_stars.
- W_Ursae_Majoris subject Category:Henry_Draper_Catalogue_objects.
- W_Ursae_Majoris subject Category:Objects_named_with_variable_star_designations.
- W_Ursae_Majoris subject Category:Ursa_Major_(constellation).
- W_Ursae_Majoris subject Category:W_Ursae_Majoris_variables.
- W_Ursae_Majoris hypernym Designation.
- W_Ursae_Majoris type CelestialBody.
- W_Ursae_Majoris type Place.
- W_Ursae_Majoris type Star.
- W_Ursae_Majoris type Catalogue.
- W_Ursae_Majoris type Variable.
- W_Ursae_Majoris type Location.
- W_Ursae_Majoris type Place.
- W_Ursae_Majoris type Thing.
- W_Ursae_Majoris comment "W Ursae Majoris (W UMa) is the variable star designation for a binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of about 7.9, which is too faint to be seen with the naked eye. However, it can be viewed with a small telescope. Parallax measurements place it at a distance of roughly 170 light years (53 parsecs) from Earth.In 1903, the luminosity of this system was found to vary by the German astronomers Gustav Müller and Paul Kempf.".
- W_Ursae_Majoris label "W Ursae Majoris".
- W_Ursae_Majoris sameAs Q1659882.
- W_Ursae_Majoris sameAs W_Ursae_Majoris.
- W_Ursae_Majoris sameAs W_Ursae_Majoris.
- W_Ursae_Majoris sameAs W_Ursae_Majoris.