Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Aries |
Right ascension | 03h 20m 20.36111s [1] |
Declination | +29° 02′ 54.4451″ [1] |
Apparent magnitude (V) | 4.47 [2] |
Characteristics | |
Spectral type | K3IIIa Ba0.5 [3] |
B−V color index | 1.555±0.020 [2] |
Astrometry | |
Radial velocity (Rv) | −3.09±0.28 [2] km/s |
Proper motion (μ) |
RA: −7.71
[1]
mas/
yr Dec.: −16.91 [1] mas/ yr |
Parallax (π) | 6.01 ± 0.25 mas [1] |
Distance | 540 ± 20
ly (166 ± 7 pc) |
Absolute magnitude (MV) | −1.63 [2] |
Details | |
Mass | 3.07±0.39 [4] M☉ |
Radius | 75.32+3.30 −7.57 [5] R☉ |
Luminosity | 1,292±89 [5] L☉ |
Surface gravity (log g) | 2.00 [4] cgs |
Temperature | 3,987+217 −85 [5] K |
Metallicity [Fe/H] | −0.27±0.04 [2] dex |
Rotational velocity (v sin i) | 1.4 [6] km/s |
Age | 350±140 [4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 20644 is a suspected binary star [6] system in the constellation Aries. It has an orange hue and is visible to the naked eye with an apparent visual magnitude of 4.47. [2] The system is located at a distance of approximately 540 light years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −3 km/s. [2]
The visible component is an aging giant star with a stellar classification of K3IIIa Ba0.5, [3] where the suffix notation indicates this is a mild barium star. The atmosphere of this star is enriched with s-process elements that are posited to have been transferred from what is now a white dwarf companion when it evolved along the asymptotic giant branch (AGB). [8] Alternatively, this star may itself be on the AGB. [9]
HD 20644 is about 350 [4] million years old with three [4] times the mass of the Sun and is spinning with a projected rotational velocity of 1.4 km/s. [6] With the supply of hydrogen at its core exhausted, it has expanded to 75 [5] times the Sun's radius. It is radiating 1,292 [5] times the luminosity of the Sun from its photosphere at an effective temperature of 3,987 K. [5]
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Aries |
Right ascension | 03h 20m 20.36111s [1] |
Declination | +29° 02′ 54.4451″ [1] |
Apparent magnitude (V) | 4.47 [2] |
Characteristics | |
Spectral type | K3IIIa Ba0.5 [3] |
B−V color index | 1.555±0.020 [2] |
Astrometry | |
Radial velocity (Rv) | −3.09±0.28 [2] km/s |
Proper motion (μ) |
RA: −7.71
[1]
mas/
yr Dec.: −16.91 [1] mas/ yr |
Parallax (π) | 6.01 ± 0.25 mas [1] |
Distance | 540 ± 20
ly (166 ± 7 pc) |
Absolute magnitude (MV) | −1.63 [2] |
Details | |
Mass | 3.07±0.39 [4] M☉ |
Radius | 75.32+3.30 −7.57 [5] R☉ |
Luminosity | 1,292±89 [5] L☉ |
Surface gravity (log g) | 2.00 [4] cgs |
Temperature | 3,987+217 −85 [5] K |
Metallicity [Fe/H] | −0.27±0.04 [2] dex |
Rotational velocity (v sin i) | 1.4 [6] km/s |
Age | 350±140 [4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 20644 is a suspected binary star [6] system in the constellation Aries. It has an orange hue and is visible to the naked eye with an apparent visual magnitude of 4.47. [2] The system is located at a distance of approximately 540 light years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −3 km/s. [2]
The visible component is an aging giant star with a stellar classification of K3IIIa Ba0.5, [3] where the suffix notation indicates this is a mild barium star. The atmosphere of this star is enriched with s-process elements that are posited to have been transferred from what is now a white dwarf companion when it evolved along the asymptotic giant branch (AGB). [8] Alternatively, this star may itself be on the AGB. [9]
HD 20644 is about 350 [4] million years old with three [4] times the mass of the Sun and is spinning with a projected rotational velocity of 1.4 km/s. [6] With the supply of hydrogen at its core exhausted, it has expanded to 75 [5] times the Sun's radius. It is radiating 1,292 [5] times the luminosity of the Sun from its photosphere at an effective temperature of 3,987 K. [5]