15 Ursae Majoris

15 Ursae Majoris
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ursa Major
Right ascension 09h 08m 52.25763s[1]
Declination +51° 36′ 16.7330″[1]
Apparent magnitude (V) 4.46[2]
Characteristics
Spectral type kA3VmF5IIISr[3]
B−V color index 0.288±0.013[2]
Astrometry
Radial velocity (Rv)−0.1±0.7[4] km/s
Proper motion (μ) RA: −136.33[1] mas/yr
Dec.: −32.60[1] mas/yr
Parallax (π)34.70 ± 0.24 mas[1]
Distance94.0 ± 0.7 ly
(28.8 ± 0.2 pc)
Absolute magnitude (MV)2.16[2]
Details
Mass1.86[5] M☉
Radius1.3[6] R☉
Luminosity11.31[2] L☉
Surface gravity (log g)3.77±0.08[7] cgs
Temperature7,519±98[7] K
Metallicity [Fe/H]0.55±0.05[7] dex
Rotational velocity (v sin i)42[8] km/s
Age220[5] Myr
Other designations
f UMa, 15 UMa, BD+52°1365, FK5 2721, GJ 3534, HD 78209, HIP 44901, HR 3619, SAO 27136[9]
Database references
SIMBADdata

15 Ursae Majoris is a star in the northern circumpolar constellation Ursa Major, located 94 light-years away from the Sun.[1] It has the Bayer designation f Ursae Majoris; 15 Ursae Majoris is the Flamsteed designation. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.46.[2] 15 Ursae Majoris is a suspected member of the Castor stellar kinematic group, a 200-million-year-old association of co-moving stars.[10]

According to Eggleton and Tokovinin (2008), this is a suspected binary star system with an orbital period of 4.9 days and an eccentricity of 0.2.[11] However, De Rosa et al. (2014) did not find a companion.[5] The primary is metallic-lined (Am) star, meaning it has unusually strong absorption lines of metals in its spectrum. Classification of the spectrum is difficult due to the peculiarities. An MK classification of 15 UMa using the calcium K line is A3 V, but using metallic spectral lines it can appear as a cooler and more luminous star. Spectral lines in the blue region give a classification of F5 Ib, while in the violet region the lines suggest F5 III/IV.[3]

  1. ^ a b c d e f Cite error: The named reference hipparcos2007 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference sreedhar1991 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 c Cite error: The named reference DeRosa2014 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference prugniel2011 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Royer2002 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference nakajima2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).