| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19 44 16.60522 |
| Declination | +37° 21′ 15.6771″ |
| Apparent magnitude (V) | 4.90 |
| Characteristics | |
| Spectral type | G8 III |
| B−V color index | 0.931 |
| Astrometry | |
| Radial velocity (Rv) | −23.62±0.21 km/s |
| Proper motion (μ) | RA: +72.660 mas/yr Dec.: +35.708 mas/yr |
| Parallax (π) | 11.0063 ± 0.1188 mas |
| Distance | 296 ± 3 ly (90.9 ± 1.0 pc) |
| Absolute magnitude (MV) | 0.19 |
| Details | |
| Mass | 2.30 M☉ |
| Radius | 12 R☉ |
| Luminosity | 93.3 L☉ |
| Surface gravity (log g) | 2.8 cgs |
| Temperature | 4,920±61 K |
| Metallicity | −0.14 dex |
| Rotational velocity (v sin i) | 2.8 km/s |
| Age | 1.50 Gyr |
| Other designations | |
| 15 Cyg, BD+37°3586, FK5 740, HD 186675, HIP 97118, HR 7517, SAO 68778 | |
| Database references | |
| SIMBAD | data |
15 Cygni is a single star in the northern constellation Cygnus. With an apparent visual magnitude of 4.90, it is a faint star but visible to the naked eye. The distance to 15 Cygni can be estimated from its annual parallax shift of 11.0 mas, which yields a separation of some 296 light years. It is moving closer to the Sun with a heliocentric radial velocity of −23.6 km/s.
This is an aging giant star with a stellar classification of G8 III, having consumed the hydrogen at its core and evolved off the main sequence. It is a red clump giant, which means it is generating energy via helium fusion at its core. The star is 1.50 billion years old with 2.3 times the mass of the Sun, and has expanded to 12 times the Sun's radius. It is radiating 93 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,920 K.
References
- ^ 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.
- ^ 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.
- ^ Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209
- Takeda, Yoichi; et al. (February 2005), "Stellar Parameters and Photospheric Abundances of Late-G Giants: Properties of the Targets of the Okayama Planet Search Program", Publications of the Astronomical Society of Japan, 57 (1): 109–125, Bibcode:2005PASJ...57..109T, doi:10.1093/pasj/57.1.109.
- "15 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-09.
- Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.