Summary
HD 85622 is a binary star system in the southern constellation of Vela. It is visible to the naked eye with an apparent visual magnitude of 4.58.[2] The distance to HD 85622 can be estimated from its annual parallax shift of 4.3 mas,[1] yielding a value of 750 light years. It is moving further from the Earth with a heliocentric radial velocity of +8 km/s.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vela |
| Right ascension | 09h 51m 40.66782s[1] |
| Declination | −46° 32′ 51.4329″[1] |
| Apparent magnitude (V) | 4.58[2] |
| Characteristics | |
| Evolutionary stage | supergiant[3] |
| Spectral type | G5 Ib[3] or G6 IIa[4] |
| B−V color index | 1.20[5] |
| Astrometry | |
| Radial velocity (Rv) | +7.8±3.2[6] km/s |
| Proper motion (μ) | RA: −24.784[1] mas/yr Dec.: +9.843[1] mas/yr |
| Parallax (π) | 4.3323 ± 0.1445 mas[1] |
| Distance | 750 ± 30 ly (231 ± 8 pc) |
| Absolute magnitude (MV) | −2.96[2] |
| Orbit[3] | |
| Period (P) | 329.266±0.085 d |
| Eccentricity (e) | 0 (adopted) |
| Periastron epoch (T) | 2453860.281±0.074 HJD |
| Semi-amplitude (K1) (primary) | 13.021±0.012 km/s |
| Details | |
| Mass | 6.2±0.5[7] M☉ |
| Luminosity | 1908.45[8] L☉ |
| Temperature | 4,796[8] K |
| Rotational velocity (v sin i) | 19.3±1.0[5] km/s |
| Age | 63.7±15.8[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary with a circular orbit and a period of 329.3 days. The a sin i value is 0.39 AU, where a is the semimajor axis and i is the orbital inclination to the line of sight.[3] This value provides a lower bound on the actual semimajor axis. The system shows a micro-variability in its brightness,[3] and is a source of X-ray emission with an apparent flux of 42.6×10−17 W/m2.[10]
The visible component is a supergiant star with a stellar classification of G5 Ib[3] or G6 IIa.[4] It is about 64[7] million years old with a projected rotational velocity of 19 km/s.[5] The star has 6.2[7] times the mass of the Sun and is radiating 1,908[8] times the Sun's luminosity from its photosphere at an effective temperature of 4,796 K.[8]
References edit
- ^ 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 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 c d e f Hearnshaw, J. B.; Komonjinda, Siramas; Skuljan, J.; Kilmartin, P. M. (November 2012), "A study of non-Keplerian velocities in observations of spectroscopic binary stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 298–310, arXiv:1211.5527, Bibcode:2012MNRAS.427..298H, doi:10.1111/j.1365-2966.2012.21802.x, S2CID 118368473
- ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373
- ^ a b c De Medeiros, J. R.; Udry, S.; Burki, G.; Mayor, M. (2002), "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars", Astronomy and Astrophysics, 395: 97–98, Bibcode:2002A&A...395...97D, doi:10.1051/0004-6361:20021214.
- ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b c d Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ a b c d McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–357, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- ^ "HD 85622". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-08-08.
- ^ Hunsch, M.; et al. (January 1998), "The ROSAT all-sky survey catalogue of optically bright late-type giants and supergiants", Astronomy and Astrophysics Supplement, 127 (2): 251–255, Bibcode:1998A&AS..127..251H, doi:10.1051/aas:1998347.