Astronomy:HD 185351
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 36m 37.977s[2] |
| Declination | +44° 41′ 41.76″[2] |
| Apparent magnitude (V) | 5.17[1] |
| Characteristics | |
| Evolutionary stage | Red-giant branch[3][4][2] |
| Spectral type | G8.5IIIb Fe−0.5[5] |
| B−V color index | 0.928±0.001[1] |
| Astrometry | |
| Radial velocity (Rv) | −5.422±0.006[6] km/s |
| Proper motion (μ) | RA: −95.016[2] mas/yr Dec.: −104.858[2] mas/yr |
| Parallax (π) | 24.261 ± 0.0573[2] mas |
| Distance | 134.4 ± 0.3 ly (41.22 ± 0.10 pc) |
| Absolute magnitude (MV) | 2.13[4] |
| Details | |
| Mass | 1.58+0.04−0.02[7] M☉ |
| Radius | 4.946±0.043[8] R☉ |
| Luminosity | 14.008±0.133[8] L☉ |
| Surface gravity (log g) | 3.288±0.046[8] cgs |
| Temperature | 5,025±22[8] K |
| Metallicity [Fe/H] | −0.02±0.07[8] dex |
| Rotational velocity (v sin i) | 2.14±0.23[9] km/s |
| Age | 2.32+0.04−0.07[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 185351 is a star in the constellation of Cygnus, the swan. With an apparent visual magnitude of 5.17,[1] it is faintly visible to the naked eye on a dark night. Based on parallax measurements, HD 185351 is located at a distance of 134 light years from the Sun.[2] It is drifting closer with a heliocentric radial velocity of −5.4 km/s.[6]
This was the third brightest star in the view field of the Kepler space telescope, with only θ Cyg and CH Cyg being brighter. The resulting data was used to measure asteroseismic oscillations that yielded a mass estimate for HD 185351, after incorporating interferometric and spectroscopic observations.[4] The result is consistent with the value of 1.60 M☉ provided by a refined stellar model.[7] In the past, the star was likely an A-type main-sequence star similar to Procyon. Hence, it is sometimes dubbed a "retired A star".[4]
HD 185351 has a stellar classification of G8.5IIIb Fe−0.5,[5] suggesting this is a late G-type giant star with a mild underabundance of iron compared to similar stars. It has expanded to nearly five times the radius of the Sun and is radiating 14 times the Sun's luminosity.[8] The star has an estimated age of 2.3 billion years[7] and is spinning with a projected rotational velocity of 2 km/s.[9]
As of 2011, searches for planetary companions using Doppler spectroscopy were unsuccessful.[4]
References
- ↑ 1.0 1.1 1.2 1.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ Stock, Stephan; Reffert, Sabine; Quirrenbach, Andreas (2018), "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search", Astronomy and Astrophysics 616: A33, doi:10.1051/0004-6361/201833111, Bibcode: 2018A&A...616A..33S.
- ↑ 4.0 4.1 4.2 4.3 4.4 Johnson, John Asher et al. (October 2014), "The physical parameters of the retired A star HD 185351", The Astrophysical Journal 794 (1): id. 15, doi:10.1088/0004-637X/794/1/15, Bibcode: 2014ApJ...794...15J.
- ↑ 5.0 5.1 Keenan, Philip C.; McNeil, Raymond C (1989), "The Perkins catalog of revised MK types for the cooler stars", The Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K.
- ↑ 6.0 6.1 Jönsson, Henrik et al. (August 17, 2020), "APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South", The Astronomical Journal (American Astronomical Society) 160 (3): 120, doi:10.3847/1538-3881/aba592, ISSN 0004-6256, Bibcode: 2020AJ....160..120J.
- ↑ 7.0 7.1 7.2 7.3 Hjørringgaard, J. G. et al. (January 2017), "Testing stellar evolution models with the retired A star HD 185351", Monthly Notices of the Royal Astronomical Society 464 (3): 3713–3719, doi:10.1093/mnras/stw2559, Bibcode: 2017MNRAS.464.3713H.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Karovicova, I.; White, T. R.; Nordlander, T.; Casagrande, L.; Ireland, M.; Huber, D. (February 2022), "Fundamental stellar parameters of benchmark stars from CHARA interferometry -- III. Giant and subgiant stars", Astronomy & Astrophysics 658: A48, doi:10.1051/0004-6361/202142100, ISSN 0004-6361.
- ↑ 9.0 9.1 Jofré, E. et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics 574: A50, doi:10.1051/0004-6361/201424474, Bibcode: 2015A&A...574A..50J.
- ↑ "HD 185351". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+185351.
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