Eta Ursae Majoris was listed as a standard star for the spectral type B3 V. It has broadenedabsorption lines due to its rapid rotation, which is common in stars of this type. However, the lines are very slightly distorted and variable, which may be caused by some emission from a weak disk of material produced by the rapid rotation.[17]
Alkaid is a relatively nearby and bright star and has been examined closely, but no exoplanets or companion stars have been discovered.[18][19]
It bore the traditional namesAlkaid (orElkeid from the Arabic القايد القائد) andBenetnasch/ˈbɛnɛtnæʃ/.[11]Alkaid derives from the Arabic phrase meaning "The leader of the daughters of thebier" (قائد بنات نعشqā'id bināt naʿsh). The daughters of the bier, i.e. the mourning maidens, are the three stars of the handle of the Big Dipper, Alkaid,Mizar, andAlioth; while the four stars of the bowl,Megrez,Phecda,Merak, andDubhe, are the bier.
It is known asBěidǒuqī (北斗七 - the Seventh Star of the Northern Dipper) orYáoguāng (瑤光 - the Star of Twinkling Brilliance) in Chinese.[21]
InJapan andKorea, Alkaid is known asHagunsei andMukokseong respectively ("the military breaking star" or "most corner star"). Both meanings come from ancient China's influence in both countries.[citation needed]
^abcDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues.2237: 0.Bibcode:2002yCat.2237....0D.
^Wielen, R.; et al. (1999). "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions".Veröff. Astron. Rechen-Inst. Heidelb.35 (35): 1.Bibcode:1999VeARI..35....1W.
^abKunitzsch, Paul; Smart, Tim (2006).A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub.ISBN978-1-931559-44-7.
^Cassinelli, J. P.; et al. (February 1994). "X-ray emission from near-main-sequence B stars".Astrophysical Journal, Part 1.421 (2):705–717.Bibcode:1994ApJ...421..705C.doi:10.1086/173683.
^Bopp, B. W; Caplinger, J. R; Crosby, N. A; Mahoney, D. F; O'Brien, S. P; Dempsey, R. C (1989). "Is the MK Standard eta UMa an Incipient be Star?".Information Bulletin on Variable Stars.3347: 1.Bibcode:1989IBVS.3347....1B.
