Omicron Ursae Majoris
star in the constellation Ursa Major
Omicron Ursae Majoris (ο Ursae Majoris, abbreviated Omicron UMa, ο UMa), formally named Muscida , is a star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.35 and is located at a distance of around 179 light-years (55 parsecs) from the Sun. In 2012, an exoplanet designated Omicron Ursae Majoris Ab was found to be orbiting the primary.
Nomenclature
ο Ursae Majoris (Latinised to Omicron Ursae Majoris) is the star's Bayer designation.
The traditional name Muscida derives from the post classical Latin musus, meaning "snout, or muzzle [of the bear]". This name was shared with the optical double star Pi Ursae Majoris. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Muscida for this star.
In Chinese, 內階 (Nèi Jiē), meaning Inner Steps, refers to an asterism consisting of ο Ursae Majoris, 16 Ursae Majoris, 6 Ursae Majoris, 23 Ursae Majoris, 5 Ursae Majoris and 17 Ursae Majoris. Consequently, the Chinese name for ο Ursae Majoris itself is 內階一 (Nèi Jiē yī, English: the First Star of Inner Steps.).
Begin with the source’s own compact description: “Omicron Ursae Majoris” is star in the constellation Ursa Major. The dossier treats that line as a proposition to test through Omicron, Ursae and Majoris, not as a finished interpretation.
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The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Sep 13, 2026. The linked authority identifier is Q956651. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2012 and 2016.
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This entry incorporates text from “Omicron Ursae Majoris” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.