HR 4138

This article is about K Carinae. For k Carinae, see HD 81101.
HR 4138
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 10h 30m 20.12710s[1]
Declination −71° 59′ 34.0602″[1]
Apparent magnitude (V) +4.72[2]
Characteristics
Spectral type A2IV[3][4] or A1V[5] or A2III[6]
B−V color index +0.042±0.007[2]
Astrometry
Radial velocity (Rv)+7.5±0.4[2] km/s
Proper motion (μ) RA: +27.59[1] mas/yr
Dec.: −30.73[1] mas/yr
Parallax (π)12.52 ± 0.17 mas[1]
Distance261 ± 4 ly
(80 ± 1 pc)
Absolute magnitude (MV)0.21[2]
Details
Mass2.10[7] M☉
Radius3.45[8] R☉
Luminosity75.06[2] L☉
Surface gravity (log g)3.71[7] cgs
Temperature9,169±312[7] K
Metallicity [Fe/H]+0.06[2] dex
Rotational velocity (v sin i)12[7] km/s
Age403[7] Myr
Other designations
K Car, CD−71°1034, FK5 2842, GC 14457, HD 91375, HIP 51438, HR 4138, SAO 256722[9]
Database references
SIMBADdata

HR 4138 is a single[10] star in the constellation Carina. It has the Bayer designation K Carinae,[11] abbreviated K Car, while HR 4138 is the star's designation in the Bright Star Catalogue. It has a white hue and is faintly visible to the naked eye with an apparent visual magnitude of +4.72.[2] This star is located at a distance of approximately 261 light years from the Sun based on parallax measurements,[1] and it is drifting further away with a radial velocity of +7.5 km/s.[2] Judging from its motion through space, it is a candidate member of the Sirius supercluster.[12]

This object is a superficially normal[4] A-type star. However, there is some disagreement over the evolutionary state of the star, as it has received luminosity classifications of a subgiant,[4] main sequence,[5] and a giant star.[6] Unexpectedly for an A-type star, a magnetic field has been detected.[4] It is around 400 million years old and has a low projected rotational velocity of 12 km/s.[7] The star displays an infrared excess,[10] indicating the presence of an orbiting debris disk with a black body temperature of 45 K at a separation of 314.2 AU from the host star.[8]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f g h Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference gray1987 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Mathys2006 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. ^ a b Cite error: The named reference Levato1972 was invoked but never defined (see the help page).
  7. ^ a b c d e f Cite error: The named reference David2015 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Cotten2016 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Rodriguez2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference xref was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Palous1986 was invoked but never defined (see the help page).