HR 3643
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]
| 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 |
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]
References edit
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d e f g h i Holberg, J. B.; et al. (2013), "Where are all the Sirius-like binary systems?", Monthly Notices of the Royal Astronomical Society, 435 (3): 2077, arXiv:1307.8047, Bibcode:2013MNRAS.435.2077H, doi:10.1093/mnras/stt1433.
- ^ a b Skiff, B. A. (October 2014), "Catalogue of Stellar Spectral Classifications", VizieR On-line Data Catalog: B/mk. Originally published in: Lowell Observatory (October 2014), Bibcode:2014yCat....1.2023S.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d Landsman, Wayne; et al. (March 1996), "The White-Dwarf Companions of 56 Persei and HR 3643", Publications of the Astronomical Society of the Pacific, 108: 250, arXiv:astro-ph/9512117, Bibcode:1996PASP..108..250L, doi:10.1086/133718, S2CID 14398914.
- ^ a b c d Barstow, M. A.; et al. (May 2014), "Evidence for an external origin of heavy elements in hot DA white dwarfs", Monthly Notices of the Royal Astronomical Society, 440 (2): 1607–1625, arXiv:1402.2164, Bibcode:2014MNRAS.440.1607B, doi:10.1093/mnras/stu216.
- ^ "G Car". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-12-11.
- ^ a b Barstow, M. A.; et al. (April 2001), "Resolving Sirius-like binaries with the Hubble Space Telescope", Monthly Notices of the Royal Astronomical Society, 322 (4): 891–900, arXiv:astro-ph/0010645, Bibcode:2001MNRAS.322..891B, doi:10.1046/j.1365-8711.2001.04203.x, S2CID 12232120.
- ^ Bilíková, Jana; et al. (November 2010), "Hard X-ray Emission Associated with White Dwarfs. III", The Astronomical Journal, 140 (5): 1433–1443, Bibcode:2010AJ....140.1433B, doi:10.1088/0004-6256/140/5/1433.