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Gamma Persei

γ Persei
Location of γ Persei (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Perseus
Right ascension 03h 04m 47.82011s[1]
Declination +53° 30′ 23.2626″[1]
Apparent magnitude (V) 2.93[2]
Characteristics
Spectral type G8III + A2V[3]
U−B color index +0.45[2]
B−V color index +0.70[2]
Variable type EA[4]
Astrometry
Radial velocity (Rv)+2.5[5] km/s
Proper motion (μ) RA: −14.194 mas/yr[1]
Dec.: −8.684 mas/yr[1]
Parallax (π)14.735 ± 0.188 mas[6]
Distance221 ± 3 ly
(67.9 ± 0.9 pc)[6]
Absolute magnitude (MV)–1.50[7] (–1.23/0.01)[8]
Orbit[8]
Period (P)14.6 yr
Semi-major axis (a)0.144″
Eccentricity (e)0.785
Inclination (i)90.9°
Longitude of the node (Ω)244.1°
Periastron epoch (T)1991.08 Besselian
Argument of periastron (ω)
(secondary)		170.0°
Details[9]
γ Per A
Mass3.6±0.2 M☉
Radius22.7±1.14 R☉
Luminosity282 L☉
Surface gravity (log g)2.23±0.08 cgs
Temperature4,970±70 K
Metallicity [Fe/H]–0.19[10] dex
Rotation5,350 days[7]
Rotational velocity (v sin i)50.0[7] km/s
γ Per B
Mass2.4±0.2 M☉
Radius3.9±0.2 R☉
Luminosity67.6 L☉
Surface gravity (log g)3.6±0.08 cgs
Temperature8,400±70 K
Other designations
γ Persei, γ Per, Gamma Per, 23 Persei, BD+52 654, CCDM J03048+5331AP, FK5 108, GC 3664, HD 18925, HIP 14328, HR 915, IDS 02576+5307 AP, PPM 28201, SAO 23789, WDS J03048+5330Aa,Ab.
Database references
SIMBADdata

Gamma Persei (Gamma Per, γ Persei, γ Per) is a binary star system in the constellation Perseus. The combined apparent visual magnitude of the pair is +2.9,[2] making it the fourth-brightest member of the constellation. The distance to this system is of roughly 221 light-years (68 parsecs) with a 1% margin of error.[6] About 4° to the north of Gamma Persei is the radiance point for the annual Perseid meteor shower.[11]

Lightcurve of Gamma Persei's 2019 eclipse recorded by NASA's Transiting Exoplanet Survey Satellite (TESS).

This is a wide eclipsing binary system with an orbital period of 5,329.8 days (14.6 years).[12] This eclipse was first observed in 1990 and lasted for two weeks.[13] During an eclipse, the primary passes in front of the secondary, causing the magnitude of the system to decrease by 0.55.[14] The primary component of this system is a giant star with a stellar classification of G9 III.[15] It has a projected rotational velocity of 50.0 km s−1 and a lengthy estimated rotation period of 14.6 years.[7] The classification of the secondary remains tentative, with assignments of A3 V[8] and A2(III).[15]

Mass estimates for the two stars remain disparate. Using speckle interferometry, McAlister (1982) obtained mass estimates of 4.73 M☉ for the primary and 2.75 M☉ for the secondary, where M☉ is the mass of the Sun. He noted that the mass estimate was too high for the given classification of the primary.[16] Martin and Mignard (1998) determined masses for both components based on data from the Hipparcos mission: 5.036 ± 0.951 M☉ for the primary and 2.295 ± 0.453 M☉ for the secondary. They admit that the high inclination of the orbit resulted in a large margin of error.[17] Prieto and Lambert (1999) came up with a mass estimate of 3.81 M☉ for the primary,[18] while Pizzolato and Maggio (2000) obtained 4.34 M☉.[7] Ling et al. (2001) obtained estimates of 2.7 M☉ for the primary and 1.65 M☉ for the secondary,[8] while Kaler (2001) obtained 2.5 and 1.9, respectively.[13] Diamant et al. (2023) found masses of 3.6 and 2.4 M☉ for A and B respectively.[9]

Name and etymology

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References

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  1. ^ a b c Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
  3. ^ Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: A69. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774.
  4. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Washington, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
  6. ^ a b c Groenewegen, M. A. T. (2023-01-01), "Orbital parallax of binary systems compared to Gaia DR3 and the parallax zero-point offset at bright magnitudes", Astronomy and Astrophysics, 669: A4, arXiv:2210.14734, Bibcode:2023A&A...669A...4G, doi:10.1051/0004-6361/202244479, ISSN 0004-6361 Gamma Persei's database entry at VizieR.
  7. ^ a b c d e Pizzolato, N.; Maggio, A.; Sciortino, S. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics, 361: 614–628, Bibcode:2000A&A...361..614P
  8. ^ a b c d Ling, J. F.; Magdalena, P.; Prieto, C. (October 2001), "Perturbations by Mass Loss in the Orbital Elements of γ Persei and α Centauri", Revista Mexicana de Astronomía y Astrofísica, 37: 179–186, Bibcode:2001RMxAA..37..179L
  9. ^ a b Diamant, S. J. M.; Schröder, K.-P.; Jack, D.; Rosas-Portilla, F.; Fridlund, M.; Schmitt, J. H. M. M. (2023-06-01), "Discovery of an extended G giant chromosphere in the 2019 eclipse of γ Per", Astronomy & Astrophysics, 674: A162, Bibcode:2023A&A...674A.162D, doi:10.1051/0004-6361/202245241, hdl:1887/3717498, ISSN 0004-6361
  10. ^ McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527
  11. ^ Burnham, Robert (1978), Burnham's celestial handbook: an observer's guide to the universe beyond the solar system, Dover books explaining science, vol. 3 (2nd ed.), Courier Dover Publications, p. 420, ISBN 0486236730
  12. ^ Pourbaix, D.; Boffin, H. M. J. (February 2003), "Reprocessing the Hipparcos Intermediate Astrometric Data of spectroscopic binaries. II. Systems with a giant component", Astronomy and Astrophysics, 398 (3): 1163–1177, arXiv:astro-ph/0211483, Bibcode:2003A&A...398.1163P, doi:10.1051/0004-6361:20021736, S2CID 12361870
  13. ^ a b Kaler, James B. (January 5, 2001), "GAMMA PER (Gamma Persei)", Stars, University of Illinois, retrieved 2012-02-25
  14. ^ Malkov, O. Yu.; et al. (February 2006), "A catalogue of eclipsing variables", Astronomy and Astrophysics, 446 (2): 785–789, Bibcode:2006A&A...446..785M, doi:10.1051/0004-6361:20053137, hdl:10995/73280
  15. ^ a b Ginestet, N.; Carquillat, J. M. (December 2002), "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components", The Astrophysical Journal Supplement Series, 143 (2): 513–537, Bibcode:2002ApJS..143..513G, doi:10.1086/342942
  16. ^ McAlister, H. A. (March 1982), "Masses and luminosities for the giant spectroscopic/speckle interferometric binaries gamma Persei and phi Cygni", Astronomical Journal, 87: 563–569, Bibcode:1982AJ.....87..563M, doi:10.1086/113130
  17. ^ Martin, C.; Mignard, F. (February 1998), "Mass determination of astrometric binaries with Hipparcos. II. Selection of candidates and results", Astronomy and Astrophysics, 330: 585–599, Bibcode:1998A&A...330..585M
  18. ^ Allende Prieto, C.; Lambert, D. L. (1999), "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures", Astronomy and Astrophysics, 352: 555–562, arXiv:0809.0359, Bibcode:1999A&A...352..555A, doi:10.1051/0004-6361/200811242, S2CID 14531031
  19. ^ Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York: Dover Publications Inc. p. 331. ISBN 0-486-21079-0. Retrieved 2012-09-04.
  20. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日 Archived 2012-02-04 at the Wayback Machine