Phi Octantis

φ Octantis
Location of Phi Oct on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 18h 23m 36.44874s[1]
Declination −75° 02′ 39.3975″[1]
Apparent magnitude (V) 5.46±0.01[2]
Characteristics
Spectral type A0 V[3]
U−B color index +0.04[4]
B−V color index +0.02[4]
Astrometry
Radial velocity (Rv)5.0±4.2[5] km/s
Proper motion (μ) RA: +4.621 mas/yr[1]
Dec.: +19.730 mas/yr[1]
Parallax (π)16.8258 ± 0.0636 mas[1]
Distance193.8 ± 0.7 ly
(59.4 ± 0.2 pc)
Absolute magnitude (MV)+1.60[6]
Details
Mass2.86[7] M☉
Radius1.74±0.08[8] R☉
Luminosity21.1±0.1[1] L☉
Surface gravity (log g)4.48±0.14[7] cgs
Temperature9,352±122[9] K
Metallicity [Fe/H]−0.22[10] dex
Rotational velocity (v sin i)295[11] km/s
Age7[7] Myr
Other designations
φ Oct, 33 G. Octantis[12], CPD−75°1417, GC 24999, HD 167468, HIP 90133, HR 6829, SAO 257584[13]
Database references
SIMBADdata

Phi Octantis, Latinized from φ Octantis, is a solitary star[14] located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.46,[2] making it faintly visible to the naked eye if viewed under ideal conditions. The object is located relatively close at a distance of 194 light years based on Gaia DR3 parallax measurements,[1] but it is receding with a heliocentric radial velocity of approximately 5 km/s.[5] At its current distance, Phi Octantis' brightness is diminished by 0.26 magnitudes due to interstellar extinction and it has an absolute magnitude of +1.60.[6]

Phi Octantis has a stellar classification of A0 V,[3] indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at is core. At present it has 2.7 times the mass of the Sun[7] and 1.74 times the radius of the Sun.[8] It radiates at 21.1 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 9,352 K,[9] giving it a white hue when viewed in the night sky. Phi Octantis is a relatively young star with an age of only 7 million years[7] and it spins rapidly with a projected rotational velocity of 295 km/s.[11] It has a metallicity only 60% of the Sun's at [Fe/H] = −0.22.

  1. ^ a b c d e f g Cite error: The named reference GaiaDR3 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 Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference A.P1999 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference starhorse was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Levato1972 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).