HR 4138

Last updated
HR 4138
Observation data
Epoch J2000        Equinox J2000
Constellation Carina [1]
Right ascension 10h 30m 20.12777s [2]
Declination −71° 59′ 34.0579″ [2]
Apparent magnitude  (V)+4.72 [1]
Characteristics
Spectral type A1V [3]
B−V color index +0.042±0.007 [1]
Variable type Rotating variable [4]
Astrometry
Radial velocity (Rv)+7.5±0.4 [1] km/s
Proper motion (μ)RA: +27.896 mas/yr [2]
Dec.: −30.148 mas/yr [2]
Parallax (π)11.7934±0.1025  mas [2]
Distance 277 ± 2  ly
(84.8 ± 0.7  pc)
Absolute magnitude  (MV)0.21 [1]
Details
Mass 2.3±0.3 [5]   M☉
Radius 3.43±0.11 [5]   R☉
Luminosity 75±4 [5]   L☉
Surface gravity (log g)3.73±0.07 [5]   cgs
Temperature 9,161±137 [5]   K
Metallicity [Fe/H]+0.06 [1]   dex
Rotation likely 3.0 to 3.2 [4] days
Rotational velocity (v sin i)12 [6]  km/s
Age 403 [6]   Myr
Other designations
K Car, CD−71°1034, FK5 2842, GC 14457, HD 91375, HIP 51438, HR 4138, SAO 256722 [7]
Database references
SIMBAD data

HR 4138 is a single [8] star in the constellation Carina. It has the Bayer designation K Carinae, [9] 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. [1] This star is located at a distance of 277  light years based on parallax measurements, [2] and it is drifting further away with a radial velocity of +7.5 km/s. [1] Judging from its motion through space, it is a candidate member of the Sirius supercluster. [10]

Characteristics

The spectrum of K Carinae matches a spectral class of AIV, [11] with the luminosity class A1V indicating that it is a main sequence star that generates energy by the fusion of helium at its core. This star is 2.3 times more massive than the Sun, with a radius 3.43 times the radius of the Sun and a luminosity 75 times solar. The effective temperature of 9,160  K [5] give it a blue-white hue typical of A-type stars. [12] It has an age estimated at 400 million years and has a low projected rotational velocity of 12 km/s. [6] Unexpectedly for an A-type star, a magnetic field has been detected. [13]

The star has an overabundance of lanthanides [11] and heavy elements [4] on its surface, and thus is classified as chemically peculiar. [11] While elements such as helium are depleted relative to the Sun, and light (Z < 30) elements have solar-like abundances, heavier elements such as barium, strontium, yttrium and zirconium are overabundant. The abundance of mercury is around 15,000 times solar. The uneven distribution of silicon and iron on its surface make K Carinae variable in the far-ultraviolet  –the variability happens due to its rotation, which is believed to have a period between 3.0 and 3.2 days. [4]

K Carinae displays an infrared excess, [8] 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. [14]

References

  1. 1 2 3 4 5 6 7 8 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv: 1108.4971 , Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID   119257644.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  3. ↑ Levato, O. H. (August 1972), "Rotational Velocities and Spectral Types of Some A-Type Stars", Publications of the Astronomical Society of the Pacific, 84 (500): 584, Bibcode:1972PASP...84..584L, doi: 10.1086/129336 .
  4. 1 2 3 4 Monier, Richard (October 2021), "The Nature of the Sharp-lined A1 V Star HR 4138", Research Notes of the AAS , 5 (10): 227, Bibcode:2021RNAAS...5..227M, doi: 10.3847/2515-5172/ac2de7 , ISSN   2515-5172.
  5. 1 2 3 4 5 6 Stassun, Keivan G.; Oelkers, Ryan J.; Paegert, Martin; Torres, Guillermo; Pepper, Joshua; De Lee, Nathan; Collins, Kevin; Latham, David W.; Muirhead, Philip S.; Chittidi, Jay; Rojas-Ayala, Bárbara; Fleming, Scott W.; Rose, Mark E.; Tenenbaum, Peter; Ting, Eric B. (2019-10-01), "The Revised TESS Input Catalog and Candidate Target List", The Astronomical Journal, 158 (4): 138, arXiv: 1905.10694 , Bibcode:2019AJ....158..138S, doi: 10.3847/1538-3881/ab3467 , ISSN   0004-6256. K Carinae's database entry at VizieR.
  6. 1 2 3 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv: 1501.03154 , Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID   33401607.
  7. ↑ "HD 91375". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-12-06.
  8. 1 2 Rodriguez, David R.; Zuckerman, B. (February 2012), "Binaries among Debris Disk Stars", The Astrophysical Journal, 745 (2): 147, arXiv: 1111.5618 , Bibcode:2012ApJ...745..147R, doi:10.1088/0004-637X/745/2/147, S2CID   73681879.
  9. ↑ Kostjuk, N. D. (2004), "VizieR Online Data Catalog: HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index (Kostjuk, 2002)", VizieR On-line Data Catalog: IV/27A. Originally Published in: Institute of Astronomy of Russian Academy of Sciences (2002), 4027, Bibcode:2004yCat.4027....0K.
  10. ↑ Palous, J.; Hauck, B. (July 1986), "The Sirius supercluster", Astronomy and Astrophysics, 162: 54–61, Bibcode:1986A&A...162...54P.
  11. 1 2 3 Monier, Richard (October 2021), "The Occurrence of Lanthanides in the Atmosphere of the A1 V Star HR 4138", Research Notes of the AAS , 5 (10): 239, Bibcode:2021RNAAS...5..239M, doi: 10.3847/2515-5172/ac3249 , ISSN   2515-5172.
  12. ↑ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2013-12-03, retrieved 2012-01-16.
  13. ↑ Mathys, G.; Hubrig, S. (July 2006), "The diagnosis of the mean quadratic magnetic field of Ap stars", Astronomy and Astrophysics, 453 (2): 699–715, Bibcode:2006A&A...453..699M, doi: 10.1051/0004-6361:20054353 .
  14. ↑ Cotten, Tara H.; Song, Inseok (July 2016), "A Comprehensive Census of Nearby Infrared Excess Stars", The Astrophysical Journal Supplement Series, 225 (1): 24, arXiv: 1606.01134 , Bibcode:2016ApJS..225...15C, doi: 10.3847/0067-0049/225/1/15 , S2CID   118438871, 15.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.