Back HD94334 CE Omega Ursae Majoris Spanish امگا خرس بزرگ Persian Omega Ursae Majoris French おおぐま座オメガ星 Japanese Omega Ursae Majoris Portuguese Омега Большой Медведицы Russian Omega Ursae Majoris Swedish Omega Ursae Majoris Turkish HD94334 Tatar

Omega Ursae Majoris

ω Ursae Majoris
Location of ω Ursae Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Ursa Major
Right ascension 10h 53m 58.74035s[1]
Declination +43° 11′ 23.8483″[1]
Apparent magnitude (V) 4.61[2]
Characteristics
Spectral type A1VsSi:[3] or A0 IV−V[4]
U−B color index −0.11[2]
B−V color index −0.04[2]
Astrometry
Radial velocity (Rv)−18.70±0.80[5] km/s
Proper motion (μ) RA: +42.97[1] mas/yr
Dec.: −23.62[1] mas/yr
Parallax (π)13.24±0.50 mas[1]
Distance246 ± 9 ly
(76 ± 3 pc)
Absolute magnitude (MV)+0.86[6]
Orbit[7]
Period (P)15.8307 d
Eccentricity (e)0.31
Periastron epoch (T)2435185.246 JD
Argument of periastron (ω)
(secondary)		27.3°
Semi-amplitude (K1)
(primary)		22.2 km/s
Details
Radius2.5[8] R☉
Luminosity76[9] L☉
Surface gravity (log g)3.88[4] cgs
Temperature9,647[9] K
Rotational velocity (v sin i)47[10] km/s
Age325[6] Myr
Other designations
ω UMa, 45 Ursae Majoris, BD+43°2058, FK5 2870, HD 94334, HIP 53295, HR 4248, SAO 43512[11]
Database references
SIMBADdata

Omega Ursae Majoris (Omega UMa, ω Ursae Majoris, ω UMa) is a binary star system in the northern circumpolar constellation of Ursa Major. It is visible to the naked eye with an apparent visual magnitude of 4.61.[2] Based upon an annual parallax shift of 13.24 mas,[1] it is roughly 246 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.11 due to interstellar dust.[6]

This is a single-lined spectroscopic binary star system with an orbital period of 15.8 days and an eccentricity of 0.31.[7] The primary member, component A, is an A-type main sequence star with a stellar classification of A1VsSi:.[3] The stellar spectrum has the appearance of a hot Am star, showing overabundances of many iron-peak and heavier elements, but an underabundance of helium.[12] In particular, it has an abnormal abundance of silicon.[13]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference adelman2004 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Pourbaix2004 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference cadars2 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Caliskan1997 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).
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