Chi Scorpii

χ Scorpii
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 16h 13m 50.906s[1]
Declination −11° 50′ 15.89″[1]
Apparent magnitude (V) 5.24[2]
Characteristics
Evolutionary stage horizontal branch(57%chance) or red giant branch(43%chance)[3]
Spectral type K3 III[4]
U−B color index +1.54[5]
B−V color index +1.39[2]
Astrometry
Radial velocity (Rv)−23.61±0.1[6] km/s
Proper motion (μ) RA: −4.991 mas/yr[1]
Dec.: −9.931 mas/yr[1]
Parallax (π)7.2874 ± 0.0993 mas[1]
Distance448 ± 6 ly
(137 ± 2 pc)
Absolute magnitude (MV)−0.08[2]
Details[3]
Mass1.22+0.13
−0.14 M☉
Radius25.92+0.78
−0.74 R☉
Luminosity179.62+11.10
−9.55 L☉
Surface gravity (log g)1.66±0.05 cgs
Temperature4,157+11
−10 K
Metallicity [Fe/H]−0.01±0.10 dex
Rotational velocity (v sin i)8[7] km/s
Age8.39±2.64 Gyr
Other designations
χ Sco, 17 Scorpii, BD−11°4096, GC 21828, HD 145897, HIP 79540, HR 6048, SAO 159793, 2MASS J16135090-1150160[8]
Database references
SIMBADdata

Chi Scorpii, Latinized from χ Scorpii, is a single[9] star in the zodiac constellation of Scorpius. It has an orange hue and can be faintly seen with the naked eye with an apparent visual magnitude of 5.24.[2][5] Based upon parallax measurements, this star is around 448 light years from the Sun.[1] The star is drifting closer with a radial velocity of −23.6 km/s.[6]

This is an aging K-type giant star with a stellar classification of K3 III,[4] which means it has exhausted the supply of hydrogen at its core. There is a 57% chance that this evolved star is on the horizontal branch and a 43% chance it is still on the red-giant branch. If it is on the former, the star is estimated to have 1.09 times the mass of the Sun, nearly 27 times the solar radius and shines with 191 times the Sun's luminosity. It is around 8 billion years old.[3]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Reffert2015 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1999 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Mermilliod1986 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference APJSS141 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Bernacca1970 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).