HD 44120

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]

  1. ^ a b c d Cite error: The named reference GaiaEDR3 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Holberg_et_al_2013 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Gray_et_al_2006 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Soubiran_et_al_2018 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Delgado_Mena_et_al_2019 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Aguilera-Gómez_et_al_2018 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Delgado_Mena2_et_al_015 was invoked but never defined (see the help page).
  10. ^ a b c d e Cite error: The named reference Bédard_et_al_2017 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference González_Hernández_et_al_2012 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Mason_et_al_1998 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Zhao_et_al_2012 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Mason_et_al_2014 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference GaiaDR2B was invoked but never defined (see the help page).