09h05m 08.81309s[1]
−72° 36′ 09.7437″[1]
4.48 + 14.50[2]
Characteristics
B−V color index
+0.607±0.010[4]
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)
Absolute magnitude (MV)
−0.98[4]
Details
A
Metallicity [Fe/H]
Rotational velocity (v sin i)
53[7] km/s
B
Surface gravity (log g)
Database references
HR 3643 is a binary star[2][7] system in the southern constellationofCarina. 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]
Other
Other
Other
NGC
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