Rho Ursae Majoris

Rho Ursae Majoris
Diagram showing star positions and boundaries of the Ursa Major constellation and its surroundings
Location of ρ Ursae Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Ursa Major
Right ascension 09h 02m 32.69092s[1]
Declination +67° 37′ 46.6280″[1]
Apparent magnitude (V) 4.74[2]
Characteristics
Spectral type M3 III[3]
U−B color index +1.84[2]
B−V color index +1.56[2]
Astrometry
Radial velocity (Rv)4.75±0.19[4] km/s
Proper motion (μ) RA: −22.83[1] mas/yr
Dec.: +18.13[1] mas/yr
Parallax (π)10.37 ± 0.25 mas[1]
Distance315 ± 8 ly
(96 ± 2 pc)
Absolute magnitude (MV)+0.06[5]
Details
Radius58[6] R☉
Luminosity464[7] L☉
Temperature3,725[7] K
Other designations
ρ UMa, 8 Ursae Majoris, BD+68°551, FK5 338, HD 76827, HIP 44390, HR 3576, SAO 14742[8]
Database references
SIMBADdata

Rho Ursae Majoris (ρ UMa) is the Bayer designation for a solitary[9] star in the northern circumpolar constellation of Ursa Major. It is faintly visible to the naked eye with an apparent visual magnitude of 4.74.[2] The distance to this star, based upon an annual parallax shift of 10.37 mas,[1] is around 315 light years.

With a stellar classification of M3 III,[3] this is a red giant star on the asymptotic giant branch.[10] It is a suspected small amplitude variable.[11] The measured angular diameter of the star after correcting for limb darkening is 5.64±0.15 mas,[12] which, at the estimated distance of this star, yields a physical size of about 58 times the radius of the Sun.[6] It is radiating 464 times the solar luminosity from its outer atmosphere at an effective temperature of about 3,725 K.[7] Based upon its motion through space, there is a 60.6% chance that this star is a member of the Sirius stream.[5]

  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 Marrese2003 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Famaey2005 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggen1992 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Percy1994 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Richichi2005 was invoked but never defined (see the help page).