CH Crucis

CH Crucis

A blue band light curve for CH Crucis, plotted from data published by Balona et al. (1992)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Crux
Right ascension 12h 41m 56.56824s[2]
Declination −59° 41′ 08.9564″[2]
Apparent magnitude (V) 4.91[3]
Characteristics
Spectral type B5III[4] or B6IV[5]
U−B color index −0.37[6]
B−V color index −0.044±0.03[3]
Variable type γ Cas?[7]
Astrometry
Radial velocity (Rv)+12.5±2.8[3] km/s
Proper motion (μ) RA: -23.987[2] mas/yr
Dec.: -4.110[2] mas/yr
Parallax (π)4.2068 ± 0.1651 mas[2]
Distance780 ± 30 ly
(238 ± 9 pc)
Absolute magnitude (MV)−2.41[3]
Details
Mass5.30±0.27[8] M☉
Radius11.20±0.22[9] R☉
Luminosity1,073[3] L☉
Surface gravity (log g)2.90±0.03[9] cgs
Temperature10,600±106[9] K
Rotational velocity (v sin i)240[10] km/s
Age120[11][better source needed] Myr
Other designations
CH Cru, CPD−59° 4393, HD 110335, HIP 61966, HR 4823, SAO 240161, G 39 Crucis[12][13]
Database references
SIMBADdata

CH Crucis is a solitary[14] variable star in the southern constellation of Crux. It has the Gould designation 39 G. Crucis.[12] The object is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude that fluctuates around 4.91.[3] The star is located approximately 780 light years distant from the Sun based on parallax,[2] and is drifting further away with a radial velocity of about +12.5 km/s.[3] It is a member of the nearby Sco OB2 association.[15]

This is a conventional shell star, which is understood to be a Be star that is being viewed edge-on.[16] Houk (1975) found a stellar classification of B5III,[4] while Hiltner et al. assigned it to B6IV;[5] suggesting it is a B-type star that is evolving off the main sequence.[8] Samus et al. (2017) have tentatively classified it as a Gamma Cassiopeiae variable that ranges in brightness from magnitude 4.88 down to 5.7.[7]

CH Crucis has 5.3[8] times the mass of the Sun and 11.2[9] times the Sun's radius. It is radiating 1,073[3] times the luminosity of the Sun from its photosphere at an effective temperature of 10,600 K.[9] It is spinning rapidly with estimates of the projected rotational velocity ranging up to 240 or 250 km/s.[16][10] This is giving the star an oblate shape with an equatorial bulge that is an estimated 18% larger than the polar radius.[10]

  1. ^ Cite error: The named reference Balona was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Hiltner1969 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference astrostudio 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 c Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  9. ^ a b c d e Cite error: The named reference Arcos2018 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference belle2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference wolframalpha was invoked but never defined (see the help page).
  12. ^ a b 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).
  15. ^ Cite error: The named reference Hoogerwerf2000 was invoked but never defined (see the help page).
  16. ^ a b Cite error: The named reference Rivinius2006 was invoked but never defined (see the help page).