Xi Octantis

ξ Octantis
Location of ξ Octantis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 22h 50m 22.8139s[1]
Declination −80° 07′ 25.8418″[1]
Apparent magnitude (V) 5.32 - 5.36[2]
Characteristics
Evolutionary stage main sequence[3]
Spectral type B6 V[4] (B5/7 V)[5]
U−B color index −0.48[6][7]
B−V color index −0.13[6]
Variable type SPB[8]
Astrometry
Radial velocity (Rv)22.1±0.5[9] km/s
Proper motion (μ) RA: +20.003 mas/yr[1]
Dec.: −12.607 mas/yr[1]
Parallax (π)6.35 ± 0.0644 mas[1]
Distance514 ± 5 ly
(157 ± 2 pc)
Absolute magnitude (MV)−0.57[10]
Details
Mass4.02±0.05[3] M☉
Radius3.0±0.5[11] R☉
Luminosity360+24
−22[3] L☉
Surface gravity (log g)4.09[11] cgs
Temperature14,050[12] K
Metallicity [Fe/H]−0.1[12] dex
Rotational velocity (v sin i)30[13] km/s
Age46+25
−16[14] Myr
Other designations
ξ Oct, 77 G. Octantis, CD−80°828, CPD−80°1055, GC 31821, HD 215573, HIP 112781, HR 8663, SAO 258946[15][16]
Database references
SIMBADdata

Xi Octantis, Latinized from ξ Octantis, is a solitary[17] variable star in the southern circumpolar constellation Octans. It has an apparent magnitude of about 5.3, allowing it to be faintly seen with the naked eye; however, this varies slightly. Located 514 light years away, the object is receding with a heliocentric radial velocity of 22 km/s.

A light curve for Xi Octantis, plotted from TESS data[18]

Xi Octantis has a stellar classification of B6 V,[4] indicating that it is an ordinary B-type main-sequence star. Hintler et al. gives it a luminosity class IV (subgiant)[19] while Houk and Cowley gives a classification intermediate between a B5 and B7 dwarf.[5] Nevertheless, it has 4 times the mass of the Sun[3] and is 3 times larger.[11] It shines with a luminosity of 360 L☉[3] from its photosphere at an effective temperature of 14,050 K,[12] giving it a whitish blue glow. Xi Octantis is 46 million years old[14] – 64.8% through its short main sequence lifetime[12] – and spins modestly with a projected rotational velocity of 30 km/s.[13]

When the Hipparcos catalogue was released in 1997, Xi Octantis was found to vary in magnitude[20] — ranging from 5.32 to 5.36 based on data from the International Variable Star Index.[2] It has since been classified as a Slowly pulsating B-dwarf with a period of 1.78 days.[2]

  1. ^ a b c d Cite error: The named reference EDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Watson2006 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Cucchiaro1977 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Houk1975 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Reed2003 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference DeCat2002 was invoked but never defined (see the help page).
  12. ^ a b c d Cite error: The named reference Smith1993 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Levato2004 was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference Grosbol1978 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Hiltner1969 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Perryman1997 was invoked but never defined (see the help page).