AF Columbae

AF Columbae

A light curve for AF Columbae, plotted from Hipparcos data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Columba
Right ascension 06h 10m 10.40393s[2]
Declination −40° 21′ 13.6464″[2]
Apparent magnitude (V) 5.60 - 5.71[3]
Characteristics
Evolutionary stage AGB[4]
Spectral type M2 II/III[5]
B−V color index +1.68[6]
Variable type Lb[7]
Astrometry
Radial velocity (Rv)−19±7.4[8] km/s
Proper motion (μ) RA: −20.650 mas/yr[2]
Dec.: +74.080 mas/yr[2]
Parallax (π)3.9737 ± 0.0841 mas[2]
Distance820 ± 20 ly
(252 ± 5 pc)
Absolute magnitude (MV)−1.53[9]
Details
Mass1.54[10] M☉
Radius148[11] R☉
Luminosity (bolometric)1,853[12] L☉
Surface gravity (log g)0.26[13] cgs
Temperature3,611±122[14] K
Other designations
82 G. Columbae[15], AF Col, NSV 2864, CD−40°2291, CPD−40°930, GC 7873, HD 42682, HIP 29263, HR 2203, SAO 217753[16]
Database references
SIMBADdata

AF Columbae, also known as HD 42682, is a solitary,[17] red hued variable star located in the southern constellation Columba, the dove. It has an apparent magnitude that fluctuates between 5.6 and 5.71.[3] Nevertheless, it is faintly visible to the naked eye. Parallax measurements from the Gaia spacecraft place the star relatively far at a distance of 820 light years.[2] However, it is approaching the Solar System with a poorly constrained radial velocity of −19 km/s.[8]

AF Columbae is a red giant that is currently on the asymptotic giant branch,[4] generating energy via hydrogen and helium shell burning. It has a stellar classification of M2 II/III,[5] indicating an evolved M-type star with the blended luminosity class of a regular giant star and a bright giant. At present it has 1.54 times the mass of the Sun[10] but has expanded to 148 times its girth.[11] It shines with a bolometric luminosity 1,853 times that of the Sun[12] from its enlarged photosphere at an effective temperature of 3,611 K.[14]

The object is classified as a slow irregular variable of subtype Lb.[7] Tabur et al. (2009) found 5 periods for AF Columbae. Most of them last for 40-50 days, while one of them last for 112 days.[18] It appears to be a runaway star, having an unusually high peculiar velocity of 93.2+4.6
−5.2 km/s.[19]

  1. ^ Cite error: The named reference HIPCurve was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Kukarkin1981 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Eggen1992 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Corben1971 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kharchenko2007 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Kervlla2019 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Kervella2021 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference McDonald2017 was invoked but never defined (see the help page).
  14. ^ a b Cite error: The named reference Stassun2019 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference SIMBAD 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 Tabur2009 was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).