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] |
Distance | 117.51 ± 0.07 ly (36.03 ± 0.02 pc) |
Absolute magnitude (MV) | 3.57[2] |
Details | |
A | |
Mass | 1.214±0.040[6] M☉ |
Radius | 1.58+0.02 −0.05[7] R☉ |
Luminosity | 2.952±0.005[7] L☉ |
Surface gravity (log g) | 4.10±0.03[8] cgs |
Temperature | 6,005±70[8] K |
Metallicity [Fe/H] | 0.09±0.06[8] dex |
Rotational velocity (v sin i) | 3.39[9] km/s |
Age | 4.105±0.755[6] Gyr |
C | |
Mass | 0.67±0.10[10] M☉ |
Radius | 0.0130±0.0003[10] R☉ |
Surface gravity (log g) | 8.04±0.06[10] cgs |
Temperature | 15,746±238[10] K |
Other designations | |
A: CD−59°1275, HD 44120, HIP 29788, HR 2274, SAO 234418 | |
C: L 182-61, WD 0615-591[3] | |
Database references | |
SIMBAD | A |
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]
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