Upsilon Octantis

υ Octantis
Location of υ Octantis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 22h 31m 37.5152s[1]
Declination −85° 58′ 02.1104″[1]
Apparent magnitude (V) 5.75±0.01[2]
Characteristics
Spectral type K0 III[3]
U−B color index +0.88[4]
B−V color index +1.02[4]
Astrometry
Radial velocity (Rv)19±7.8[5] km/s
Proper motion (μ) RA: −37.556 mas/yr[1]
Dec.: +61.431 mas/yr[1]
Parallax (π)9.5042 ± 0.0351 mas[1]
Distance343 ± 1 ly
(105.2 ± 0.4 pc)
Absolute magnitude (MV)+0.77[6]
Details[7]
Mass2.12±0.07 M☉
Radius10.3±0.2 R☉
Luminosity56±1.1 L☉
Surface gravity (log g)2.7±0.1 cgs
Temperature4,910±42 K
Metallicity [Fe/H]0.00±0.03 dex
Rotational velocity (v sin i)1.5±1.3[8] km/s
Other designations
υ Oct, 71 G. Octantis[9], CPD−86°406, FK5 1670, GC 31327, HD 211539, HIP 111196, HR 8505, SAO 258932[10]
Database references
SIMBADdata

Upsilon Octantis (Upsilon Oct), Latinized from υ Octantis, is a solitary star[11] in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude of 5.75[2] and is located 343 light years away from the Solar System.[1] However, it is receding with a heliocentric radial velocity of 19 km/s.[5]

Upsilon Oct has a stellar classification of K0 III,[3] indicating that it is a red giant. At present it has 2.12 times the mass of the Sun but has expanded to 10.3 times its girth.[7] It shines with a luminosity of 56 L☉ from its enlarged photosphere at an effective temperature of 4,910 K,[7] giving a yellowish orange hue when viewed at night. Upsilon Oct has a solar metallicity, with an iron abundance equivalent to the Sun's.[7] It spins leisurely with a poorly-constrained projected rotational velocity of 1.5 km/s.[8]

  1. ^ a b c d e Cite error: The named reference EDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Karchenko2007 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Ottoni2022 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference DeMed2014 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Gould1879 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 Eggleton2008 was invoked but never defined (see the help page).