CK Carinae

CK Carinae

An I band (near infrared) light curve for CK Carinae, plotted from ASAS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 10h 24m 25.36s[2]
Declination −60° 11′ 29.0″[2]
Apparent magnitude (V) 7.2 - 8.5[3]
Characteristics
Spectral type M3.5 Iab[4]
B−V color index +2.21[2]
Variable type SRc[4]
Astrometry
Radial velocity (Rv)−3.92[5] km/s
Proper motion (μ) RA: −7.351[5] mas/yr
Dec.: 2.995[5] mas/yr
Parallax (π)0.4286 ± 0.0806 mas[5]
Distance2,920+190
−150[6] pc
Absolute magnitude (MV)−6.31[2]
Details
Mass15[7] M☉
Radius690[7] R☉
Luminosity72,000[7] L☉
Surface gravity (log g)0[7] cgs
Temperature3,500[7] K
Metallicity [Fe/H]0.05[8] dex
Other designations
CK Car, CD−59°3058, HD 90382, SAO 238038
Database references
SIMBADdata

CK Carinae (CK Car / HD 90382 / SAO 238038) is a variable star in the constellation Carina, the keel of Argo Navis. It is a member of the star association Carina OB1-D, at a distance of around 2,300 parsecs or 7,500 light years.

Classified as a semiregular variable star, CK Carinae's brightness varies between apparent magnitudes +7.2 and +8.5 with a period of approximately 525 days.[3] It has a Gaia Data Release 2 parallax of 0.4286±0.0806 mas,[5] which implies a distance of around 2,300 pc, and is thought to be a member of the Carina OB1-D stellar association which is at a distance of about 2,200 pc.[2][9] An analysis of the distances of apparently-nearby OB stars implies a distance of 2,920 pc for CK Carinae.[6] It has an MK spectral classification of M3.5 Iab, with the luminosity class indicating an intermediate luminosity supergiant.[4]

CK Carinae is a red supergiant with an effective temperature of 3,500 K.[7] It is 690 times larger than the Sun,[7] which means that if it were in the place of the Sun, its surface would reach beyond the orbit of Mars, with Earth being encompassed within the star. Consequently, CK Carinae is also a luminous star, radiating 72,000 times as much energy as the sun.[7]

  1. ^ Cite error: The named reference ASASServer was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference levesque was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference kiss was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  5. ^ a b c d e Cite error: The named reference dr2 was invoked but never defined (see the help page).
  6. ^ a b Davies, Ben; Beasor, Emma R. (March 2020). "The 'red supergiant problem': the upper luminosity boundary of Type II supernova progenitors". MNRAS. 493 (1): 468–476. arXiv:2001.06020. Bibcode:2020MNRAS.493..468D. doi:10.1093/mnras/staa174. S2CID 210714093.
  7. ^ a b c d e f g h González-Torà, G.; Wittkowski, M.; Davies, B.; Plez, B. (2024). "The effect of winds on atmospheric layers of red supergiants II. Modelling VLTI/GRAVITY and MATISSE observations of AH Sco, KW SGR, V602 Car, CK Car, and V460 Car". Astronomy & Astrophysics. 683: A19. arXiv:2312.12521. Bibcode:2024A&A...683A..19G. doi:10.1051/0004-6361/202348047.
  8. ^ Cite error: The named reference starhorse was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference messinio was invoked but never defined (see the help page).