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HD 44120

Coordinates: Sky map 06h 16m 19s, −59° 12′ 49″
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HD 44120
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pictor
Right ascension 06h 16m 18.786s[1]
Declination −59° 12′ 48.61″[1]
Apparent magnitude (V) 6.44[2] + 14.03[3]
Characteristics
Spectral type F9.5V[4] + DB3.2[3]
B−V color index 0.593±0.015[2]
Astrometry
A
Radial velocity (Rv)−2.125±0.0003[5] km/s
Proper motion (μ) RA: −45.187 mas/yr[1]
Dec.: −316.389 mas/yr[1]
Parallax (π)27.7563 ± 0.0172 mas[1]
Distance117.51 ± 0.07 ly
(36.03 ± 0.02 pc)
Absolute magnitude (MV)3.57[2]
Details
A
Mass1.214±0.040[6] M☉
Radius1.58+0.02
−0.05[7] R☉
Luminosity2.952±0.005[7] L☉
Surface gravity (log g)4.10±0.03[8] cgs
Temperature6,005±70[8] K
Metallicity [Fe/H]0.09±0.06[8] dex
Rotational velocity (v sin i)3.39[9] km/s
Age4.105±0.755[6] Gyr
C
Mass0.67±0.10[10] M☉
Radius0.0130±0.0003[10] R☉
Surface gravity (log g)8.04±0.06[10] cgs
Temperature15,746±238[10] K
Other designations
GJ 9209, WDS J06163-5913[11]
A: CD−59°1275, HD 44120, HIP 29788, HR 2274, SAO 234418
C: L 182-61, WD 0615-591[3]
Database references
SIMBADA
C

HD 44120 is a wide binary star system in the southern constellation of Pictor. Although visible to the naked eye, it is a challenge to view having an apparent visual magnitude of 6.44.[2] The system is located at a distance of 118 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −2 km/s.[5] It has an absolute magnitude of 3.57.[2]

The primary member, designated component A of this system, is an F-type main-sequence star with a stellar classification of F9.5V.[4] It is a Sun-like star and has been considered a "hot" solar analog with a shallower convection zone than the Sun.[12] The estimated age of this star is about four billion years,[6] and it is spinning with a projected rotational velocity of 3.4 km/s.[9] It is chromospherically inactive.[13] The star has 1.2[6] times the mass of the Sun and 1.6[7] times the Sun's radius. It is radiating nearly three[7] times the luminosity of the Sun from its photosphere at an effective temperature of 6,005 K.[8]

The faint secondary companion, component C, is a magnitude 14.03 white dwarf star with a class of DB3.2,[3] indicating a helium-rich atmosphere. The object has an effective temperature of ~15,700 K with 67% of the Sun's mass but only 1.3% of the Sun's radius.[10] It has taken 155±16 Myr for the white dwarf to have cooled to the current temperature. Prior to leaving the main sequence, this star is estimated to have had 1.45+0.20
−0.16 M☉ and thus was the system primary.[14] It has an angular separation of 40.98″ along a position angle of 301.6° from the current primary. The projected separation of this co-moving pair is 1,533.9 AU. Their estimated orbit has a semimajor axis of 1,702.6 AU and an orbital period of 51,100 years.[3]

A magnitude 7.61 visual companion, HD 44105, or component B, lies at an angular separation of 32.50″ along a position angle of 234° from component A, as of 2015. It was discovered as a double star by the Scottish astronomer James Dunlop and announced in 1829.[15] The parallax for this star indicates a distance of approximately 215 ly (66 pc) from the Sun.[16]

References

[edit]
  1. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. ^ a b c d e 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
  3. ^ a b c d e Holberg, J. B.; et al. (2013), "Where are all the Sirius-like binary systems?", Monthly Notices of the Royal Astronomical Society, 435 (3): 2077, arXiv:1307.8047, Bibcode:2013MNRAS.435.2077H, doi:10.1093/mnras/stt1433
  4. ^ a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc—The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992
  5. ^ a b Soubiran, C.; et al. (2018), "Gaia Data Release 2. The catalogue of radial velocity standard stars", Astronomy and Astrophysics, 616: A7, arXiv:1804.09370, Bibcode:2018A&A...616A...7S, doi:10.1051/0004-6361/201832795, S2CID 52952408
  6. ^ a b c d Delgado Mena, E.; et al. (April 2019), "Abundance to age ratios in the HARPS-GTO sample with Gaia DR2. Chemical clocks for a range of [Fe/H]", Astronomy & Astrophysics, 624: 24, arXiv:1902.02127, Bibcode:2019A&A...624A..78D, doi:10.1051/0004-6361/201834783, S2CID 90259810, A78
  7. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  8. ^ a b c d Aguilera-Gómez, Claudia; et al. (June 2018), "Lithium abundance patterns of late-F stars: an in-depth analysis of the lithium desert", Astronomy & Astrophysics, 614: 15, arXiv:1803.05922, Bibcode:2018A&A...614A..55A, doi:10.1051/0004-6361/201732209, S2CID 62799777, A55
  9. ^ a b Delgado Mena, E.; et al. (April 2015), "Li abundances in F stars: planets, rotation, and Galactic evolution", Astronomy & Astrophysics, 576: 24, arXiv:1412.4618, Bibcode:2015A&A...576A..69D, doi:10.1051/0004-6361/201425433, S2CID 56051637, A69
  10. ^ a b c d e Bédard, A.; et al. (2017), "Measurements of Physical Parameters of White Dwarfs: A Test of the Mass-Radius Relation", The Astrophysical Journal, 848 (1): 11, arXiv:1709.02324, Bibcode:2017ApJ...848...11B, doi:10.3847/1538-4357/aa8bb6, S2CID 119359723
  11. ^ "HD 44120". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-26.
  12. ^ González Hernández, J. I.; et al. (April 2012), Richards, M. T.; Hubeny, I. (eds.), "Searching for the Signatures of Terrestrial Planets in Hot Analogs", From Interacting Binaries to Exoplanets: Essential Modeling Tools, Proceedings of the International Astronomical Union, IAU Symposium, vol. 282, pp. 480–481, Bibcode:2012IAUS..282..480G, doi:10.1017/S1743921311028183
  13. ^ Mason, Brian D.; et al. (December 1998), "A Multiplicity Survey of Chromospherically Active and Inactive Stars", The Astronomical Journal, 116 (6): 2975–2983, Bibcode:1998AJ....116.2975M, doi:10.1086/300654
  14. ^ Zhao, J. K.; et al. (February 2012), "The Initial-Final Mass Relation among White Dwarfs in Wide Binaries", The Astrophysical Journal, 746 (2): 11, arXiv:1112.0281, Bibcode:2012ApJ...746..144Z, doi:10.1088/0004-637X/746/2/144, S2CID 54874378, 144
  15. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
  16. ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.


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