HD 99706

HD 99706
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 11h 28m 30.2137s[1]
Declination +43° 57′ 59.6854″[1]
Apparent magnitude (V) 7.65[2]
Characteristics
Evolutionary stage Subgiant[2]
Spectral type K0[3]
B−V color index 1.0[4]
Astrometry
Radial velocity (Rv)−30.07[1] km/s
Proper motion (μ) RA: 45.406[1] mas/yr
Dec.: −87.500[1] mas/yr
Parallax (π)6.7929 ± 0.0518 mas[1]
Distance480 ± 4 ly
(147 ± 1 pc)
Absolute magnitude (MV)2.12[5]
Details[2]
Mass1.46 M☉
Radius5.52 R☉
Luminosity13.1±0.1[6] L☉
Surface gravity (log g)3.09 cgs
Temperature4,862 K
Metallicity [Fe/H]0.05[7] dex
Rotational velocity (v sin i)1.8±0.6[7] km/s
Age2.8±0.2[6] Gyr
Other designations
BD+44°2096, HD 99706, HIP 55994, TYC 3015-1137-1, 2MASS J11283020+4357597[8]
Database references
SIMBADdata

HD 99706 is an orange-hued star in the northern circumpolar constellation of Ursa Major. With an apparent visual magnitude of 7.65,[2] it is too dim to be visible to the naked eye but can be viewed with a pair of binoculars.[9] Parallax measurements provide a distance estimate of approximately 480 light years from the Sun, and the Doppler shift shows it is drifting closer with a radial velocity of −30 km/s.[1] It has an absolute magnitude of 2.12,[5] indicating it would be visible to the naked eye as a 2nd magnitude star if it were located 10 parsecs away.

This is an aging subgiant[2] star belonging to spectral class K0,[3] having exhausted the supply of hydrogen at its core and begun to evolve into a giant. Its age is younger than the Sun's at 2.8±0.2 billion years and it is spinning slowly with a projected rotational velocity of 2 km/s.[7] The star has 1.5 times the mass of the Sun and has expanded to 5.5 times the Sun's radius. It is slightly enriched in heavy elements, having 110% of solar abundance.[7] HD 99706 is radiating 13[6] times the luminosity of the Sun from its photosphere at an effective temperature of 4,862 K.[2]

An imaging survey at Calar Alto Observatory in 2016 failed to detect any stellar companions to HD 99706.[10]

  1. ^ a b c d e f g Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Luhn2018 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cannon_Pickering_1993 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Johnson2011 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Bonfanti2014 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Ghezzi2018 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 ICQ was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Mugrauer_et_al_2016 was invoked but never defined (see the help page).