Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Carina |
Right ascension | 09h 05m 08.81309s [1] |
Declination | −72° 36′ 09.7437″ [1] |
Apparent magnitude (V) | 4.48 + 14.50 [2] |
Characteristics | |
Spectral type | F8II [3] + DA1.6 [2] |
B−V color index | +0.607±0.010 [4] |
Astrometry | |
Radial velocity (Rv) | +22.5±0.7 [5] km/s |
Proper motion (μ) |
RA: −8.81
[1]
mas/
yr Dec.: −5.26 [1] mas/ yr |
Parallax (π) | 8.14 ± 0.15 mas [1] |
Distance | 401 ± 7
ly (123 ± 2 pc) |
Absolute magnitude (MV) | −0.98 [4] |
Details | |
A | |
Radius | 13.15+1.03 −0.53 [6] R☉ |
Luminosity | 206.2±5.4 [6] L☉ |
Temperature | 6,030+127 −222 [6] K |
Metallicity [Fe/H] | −0.04±0.04 [4] dex |
Rotational velocity (v sin i) | 53 [7] km/s |
B | |
Mass | 0.74 [2] M☉ |
Surface gravity (log g) | 7.47 [8] cgs |
Temperature | 21,551 [8] K |
Age | 25 [8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HR 3643 is a binary star [2] [7] system in the southern constellation of Carina. It has the Bayer designation G Carinae, with HR 3643 being the star's designation in the Bright Star Catalogue. The system is visible to the naked eye with an apparent visual magnitude of 4.48. [2] It is located at a distance of approximately 401 light years from the Sun based on parallax, [1] and is drifting further away with a radial velocity of +22.5 km/s. [5]
The binary nature of this system was first detected as an ultraviolet excess in 1996. No radial velocity variation has been detected so it must be a wide system with an orbital period of up to 21 years. [10] The estimated semimajor axis of their orbit is 10.90 AU. [2] The pair were not resolved using the Hubble Space Telescope WFPC2 instrument. [10]
The primary is an evolved bright giant star with a yellow-white hue and a stellar classification of F8II. [3] With the supply of hydrogen exhausted at its core, it has expanded to 13 [6] times the Sun's radius. It has a relatively high projected rotational velocity of 53 km/s for a star of this class, suggesting it is an intermediate-mass star with 2–5 times the mass of the Sun. [7] The star is radiating 206 [6] times the luminosity of the Sun from its photosphere at an effective temperature of 6,030 K. [6]
The magnitude 14.50 [2] companion is a white dwarf with a class of DA1.6. [2] It has a mass estimated at 74% [2] of the mass of the Sun and a temperature of 21,551 K, indicating a cooling time of 25 million years. [8] This object is a source for hard X-ray emission. [11] The primary is one of the most massive stars known to have a white dwarf companion. [7]