57 Persei

57 Persei, or m Persei, is a suspected triple star[12] system in the northern constellation of Perseus. It is at the lower limit of visibility to the naked eye, having a combined apparent visual magnitude of 6.08.[2] The annual parallax shift of 16.90 mas provides a distance estimate of about 193 light years. 57 Persei is moving closer to the Sun with a radial velocity of about −23[7] km/s and will make perihelion in around 2.6 million years at a distance of roughly 22 ly (6.6 pc).[13]

57 Persei

Observation data Epoch J2000      Equinox J2000
Constellation	Perseus
A
Right ascension	04^h 33^m 24.90359^s[1]
Declination	+43° 03′ 50.0289″[1]
Apparent magnitude (V)	6.078[2]
B
Right ascension	04^h 33^m 21.6085^s[3]
Declination	+43° 01′ 54.917″[3]
Apparent magnitude (V)	6.81[2]
Characteristics
Spectral type	F0 V[4] + ?
U−B color index	+0.01[5]
B−V color index	+0.38[5]
Spectral type	A8Vs[6]
B−V color index	+0.18[2]
Astrometry
A
Radial velocity (Rv)	−23.0±4.3[7] km/s
Proper motion (μ)	RA: +5.60[1] mas/yr Dec.: +7.03[1] mas/yr
Parallax (π)	16.90 ± 0.53[1] mas
Distance	193 ± 6 ly (59 ± 2 pc)
Absolute magnitude (MV)	+2.23[6]
B
Radial velocity (Rv)	+2.20±1.78[8] km/s
Proper motion (μ)	RA: +24.120[3] mas/yr Dec.: −59.916[3] mas/yr
Parallax (π)	13.80 ± 0.42[3] mas
Distance	236 ± 7 ly (72 ± 2 pc)
Absolute magnitude (MV)	+2.56[6]
Details
57 Persei A
Mass	1.28[9] M☉
Luminosity	7.88[6] L☉
Surface gravity (log g)	3.87[9] cgs
Temperature	6,615±225[9] K
Metallicity [Fe/H]	−0.19[10] dex
Rotational velocity (v sin i)	90[4] km/s
Age	1.614[9] Gyr
57 Persei B
Mass	1.74[9] M☉
Luminosity	10.69[6] L☉
Surface gravity (log g)	4.45[9] cgs
Temperature	8,247±280[9] K
Age	358[9] Myr
Other designations
m Per, 57 Per, FK5 1124, HR 1434, WDS J04334+4304[11]
A: BD+42° 990, HD 28704, HIP 21242, SAO 39604
B: BD+42° 989, HD 28693, HIP 21238, SAO 39602
Database references
SIMBAD	data
	HD 28704
	HD 28693

The primary member, designated component A, is a magnitude 6.18,[12] yellow-white hued F-type main-sequence star with a stellar classification of F0 V,[4] indicating it is generating energy by fusing its core hydrogen. It is an estimated 1.6[9] billion years old and is spinning with a projected rotational velocity of 90 km/s.[4] The star has 1.3[9] times the mass of the Sun and is radiating 10.7[6] times the Sun's luminosity from its photosphere at an effective temperature of around 6,615 K.[9]

An unseen companion has been identified via slight changes to the proper motion of the primary.[12] The third member, component B,[14] is a magnitude 6.87 F-type star at an angular separation of 120.13 arc seconds.[12] This star has a different parallax and space velocity than the primary,[1][3] so it may just be a wide visual companion.[14] There are three other nearby visual companions that are not associated with the 57 Persei system.[14]

References

1. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
2. Høg, E.; et al. (2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862.
3. Gaia Collaboration; et al. (November 2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy & Astrophysics. 595: 23. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. A2.
4. Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
5. Dorrit Hoffleit (1991). Combined\bsc5: The Bright Star Catalogue. 5th Ed., Preliminary Version. Yale University Observatory.
6. 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.
7. 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, A61.
8. Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776.
9. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
10. 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.
11. "57 Per". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-30.
12. 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.
13. Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, A35.
14. Mason, B. D.; et al. (2014), The Washington Visual Double Star Catalog, Bibcode:2001AJ....122.3466M, doi:10.1086/323920