Omega2 Scorpii

For other stars with this Bayer designation, see ω Scorpii
ω2 Scorpii
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Scorpius
Right ascension 16h 07m 24.32818s[1]
Declination −20° 52′ 07.5518″[1]
Apparent magnitude (V) +4.320[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type G6/8III[4]
U−B color index +0.494[2]
B−V color index +0.850[2]
Astrometry
Radial velocity (Rv)−5.4[5] km/s
Proper motion (μ) RA: +44.81[1] mas/yr
Dec.: −45.42[1] mas/yr
Parallax (π)11.22 ± 0.32 mas[1]
Distance291 ± 8 ly
(89 ± 3 pc)
Absolute magnitude (MV)−0.62[6]
Details
Mass3.27[6] M☉
Radius15.0[7] R☉
Luminosity163[7] L☉
Surface gravity (log g)2.62±0.11[8] cgs
Temperature5,363±42[8] K
Metallicity [Fe/H]+0.03±0.05[8] dex
Age282[6] Myr
Other designations
Jabhat al Akrab,[9] ω2 Sco, 10 Scorpii, BD−20°4408, HD 144608, HIP 78990, HR 5997, SAO 184135[10]
Database references
SIMBADdata

ω2 Scorpii, Latinised as Omega2 Scorpii, is a suspected[11] variable star in the zodiac constellation of Scorpius. A component of the visual double star ω Scorpii, it is bright enough to be seen with the naked eye having an apparent visual magnitude of +4.320.[2] The distance to this star, as determined using parallax measurements,[1] is around 291 light years. The visual magnitude of this star is reduced by 0.38 because of extinction from interstellar dust.[6]

It is 0.05 degree north of the ecliptic, so can be occulted by the moon and planets.

This is a G-type giant star with a stellar classification of G6/8III.[4] With an estimated age of 282 million years,[6] it is an evolved, thin disk star that is currently on the red horizontal branch.[3] The interferometry-measured angular diameter of this star is 1.63 ± 0.10 mas,[12] which, at its estimated distance, equates to a physical radius of nearly 16 times the radius of the Sun.[13] It has 3.27 times the mass of the Sun,[6] and radiates 141 times the Sun's luminosity[14] The effective temperature of the star's outer atmosphere is 5,363 K.[8]

  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 Kozok1985 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Afsar2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1988 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcsrv was invoked but never defined (see the help page).
  6. ^ a b c d e f Cite error: The named reference Takeda2008 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference dr2 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference prugniel2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference allen1899 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Sterken1977 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Richichi2002 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).