36 Persei

36 Persei is a solitary,^[8] variable star located 121 light years away from the Sun in the northern constellation of Perseus. It is visible to the naked eye as a dim, yellow-white hued point of light with a baseline apparent visual magnitude of 5.32.^[2] The star is drifting closer to the Sun with a heliocentric radial velocity of −47.5 km/s,^[4] and may come as close as 36.6 light-years in 661,000 years.^[5]

36 Persei

Location of 36 Persei (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Perseus
Right ascension	03h 32m 26.25886s[1]
Declination	46° 03′ 24.7029″[1]
Apparent magnitude (V)	5.32[2]
Characteristics
Spectral type	F4III[3]
U−B color index	−0.02[2]
B−V color index	+0.41[2]
Astrometry
Radial velocity (Rv)	−47.5[4] km/s
Proper motion (μ)	RA: −52.829[1] mas/yr Dec.: −74.915[1] mas/yr
Parallax (π)	26.9895 ± 0.1053 mas[1]
Distance	120.8 ± 0.5 ly (37.1 ± 0.1 pc)
Absolute magnitude (MV)	2.50[5]
Details
Mass	1.50[4] M☉
Radius	2.28+0.13 −0.09[1] R☉
Luminosity	8.585±0.042[1] L☉
Surface gravity (log g)	3.94[4] cgs
Temperature	6,546+126 −176[1] K
Metallicity [Fe/H]	−0.17[4] dex
Rotational velocity (v sin i)	28.0[6] km/s
Age	2.20[4] Gyr
Other designations
36 Per, NSV 1182, BD+45°778, FK5 2249, GC 4210, HD 21770, HIP 16499, HR 1069, SAO 38924[7]
Database references
SIMBAD	data

The stellar classification of 36 Persei is F4III,^[3] matching an aging giant star that has used up its core hydrogen. This object is used by astronomers as a spectral standard for stars with a similar class.^[9] The star is a suspected variable of unknown type, ranging in visual magnitude from 5.29 down to 5.33,^[10] and is a source of X-ray emission.^[11] The star is 2.2^[4] billion years old with a projected rotational velocity of 28 km/s.^[6] It has an estimated 1.5^[4] times the mass of the Sun and has not yet expanded significantly, having 2.3^[1] times the Sun's girth. The star is radiating 8.6^[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,546 ^[1]

References

1. 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.
2. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
3. Ljunggren, B.; Oja, T. (1961). "The Uppsala spectral classification". Uppsala Astronomical Observatory Annual. 4 (10): 10. Bibcode:1961UppAn...4j...1L.
4. Casagrande, L.; et al. (June 2011). "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey". Astronomy and Astrophysics. 530: A138. arXiv:1103.4651. Bibcode:2011A&A...530A.138C. doi:10.1051/0004-6361/201016276. S2CID 56118016.
5. 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. Vizier catalog entry
6. De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M. (2014). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 561: A126. arXiv:1312.3474. Bibcode:2014A&A...561A.126D. doi:10.1051/0004-6361/201220762. S2CID 54046583. Vizier catalog entry
7. "36 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-14.
8. 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.
9. Garcia, B. (1989). "A list of MK standard stars". Bulletin d'Information du Centre de Données Stellaires. 36: 27. Bibcode:1989BICDS..36...27G.
10. Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
11. Haakonsen, Christian Bernt; Rutledge, Robert E. (September 2009). "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources". The Astrophysical Journal Supplement. 184 (1): 138–151. arXiv:0910.3229. Bibcode:2009ApJS..184..138H. doi:10.1088/0067-0049/184/1/138. S2CID 119267456.