Summary
72 Cygni is a star in the northern constellation of Cygnus, located 299 light years from the Sun[1] and a member of the Hercules stream.[8] It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.87.[2] 72 Cyg is moving closer to the Earth with a heliocentric radial velocity of −68 km/s.[6] It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.154″ per year.[10]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 34m 46.58574s[1] |
| Declination | +38° 32′ 02.6267″[1] |
| Apparent magnitude (V) | 4.87[2] |
| Characteristics | |
| Spectral type | K0.5 III Fe0.5[3] or K0.5 III CN 0.5[4] + M5[5] |
| B−V color index | 1.092[6] |
| Astrometry | |
| Radial velocity (Rv) | −68.12±0.11[6] km/s |
| Proper motion (μ) | RA: +113.665[1] mas/yr Dec.: +100.403[1] mas/yr |
| Parallax (π) | 14.2468 ± 0.1339 mas[1] |
| Distance | 229 ± 2 ly (70.2 ± 0.7 pc) |
| Absolute magnitude (MV) | 0.62[2] |
| Details | |
| Mass | 1.70[7] M☉ |
| Radius | 14[6] R☉ |
| Luminosity | 69[7] L☉ |
| Surface gravity (log g) | 2.68±0.04[8] cgs |
| Temperature | 4,640±25[7] K |
| Metallicity [Fe/H] | 0.18[8] dex |
| Rotational velocity (v sin i) | 1.4[6] km/s |
| Age | 900±200[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an aging giant star with a stellar classification of K0.5 III Fe0.5,[3] where the suffix notation indicates a mild underabundance of iron in the spectrum. It has 1.7[7] times the mass of the Sun but has expanded to 14[6] times the Sun's radius. The star is radiating 69[7] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,640 K.[7]
72 Cygni has a wide companion at an angular separation of 66.1″, corresponding to a projected separation of 4,690 AU. This star has a J band (infrared) magnitude of 13.224±0.025 and a class of M5.[5]
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 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.
- ^ Keenan, Philip C.; et al. (July 1987). "Recognition and classification of strong-CN giants". Publications of the Astronomical Society of the Pacific. 99: 629–636. Bibcode:1987PASP...99..629K. doi:10.1086/132025.
- ^ a b Deacon, Niall R.; et al. (September 2014), "Wide Cool and Ultracool Companions to Nearby Stars from Pan-STARRS 1", The Astrophysical Journal, 792 (2): 40, arXiv:1407.2938, Bibcode:2014ApJ...792..119D, doi:10.1088/0004-637X/792/2/119, S2CID 38354181, 119.
- ^ a b c d e f 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, S2CID 121883397.
- ^ a b c d e f Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ a b c d Ramya, P.; et al. (August 2016), "Chemical compositions and kinematics of the Hercules stream", Monthly Notices of the Royal Astronomical Society, 460 (2): 1356−1370, arXiv:1604.04821, Bibcode:2016MNRAS.460.1356R, doi:10.1093/mnras/stw852.
- ^ "72 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-20.
- ^ Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)", The Astronomical Journal, 129 (3): 1483–1522, arXiv:astro-ph/0412070, Bibcode:2005AJ....129.1483L, doi:10.1086/427854, S2CID 2603568.