  | |
| 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 | |
| Evolutionary stage | Blue straggler + late main sequence/subgiant[3] |
| Spectral type | G8III + A2V[4] |
| U−B color index | +0.45[2] |
| B−V color index | +0.70[2] |
| Variable type | EA[5] |
| Astrometry | |
| Radial velocity (Rv) | +2.5[6] km/s |
| Proper motion (μ) | RA: −14.194 mas/yr[1] Dec.: −8.684 mas/yr[1] |
| Parallax (π) | 14.735±0.188 mas[7] |
| Distance | 221 ± 3 ly (67.9 ± 0.9 pc)[7] |
| Absolute magnitude (MV) | –1.50[8] (–1.23/0.01)[9] |
| Orbit[9] | |
| 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[10] | |
| γ Per A | |
| Mass | 3.6±0.2 M☉ |
| Radius | 22.7±1.14 R☉ |
| Luminosity | 282 L☉ |
| Surface gravity (log g) | 2.23±0.08 cgs |
| Temperature | 4,970±70 K |
| Metallicity [Fe/H] | –0.19[11] dex |
| Rotation | 5,350 days[8] |
| Rotational velocity (v sin i) | 50.0[8] km/s |
| Age | 750–900[3] Myr |
| γ Per B | |
| Mass | 2.4±0.2 M☉ |
| Radius | 3.9±0.2 R☉ |
| Luminosity | 67.6 L☉ |
| Surface gravity (log g) | 3.6±0.08 cgs |
| Temperature | 8,400±70 K |
| Age | 750–900[3] Myr |
| 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 | |
| SIMBAD | data |
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.[7] About 4° to the north of Gamma Persei is the radiant point for the annual Perseid meteor shower.[12]
This is a wide eclipsing binary system with an orbital period of 5,329.8 days (14.6 years).[13] This eclipse was first observed in 1990 and lasted for two weeks.[14] During an eclipse, the primary passes in front of the secondary, causing the magnitude of the system to decrease by 0.55.[15] The primary component of this system is a giant star with a stellar classification of G9 III.[16] It has a projected rotational velocity of 50.0 km s−1 and a lengthy estimated rotation period of 14.6 years.[8] The classification of the secondary remains tentative, with assignments of A3 V[9] and A2(III).[16] The secondary component appears to be much older than the primary, based on estimates derived by evolutionary tracks. Therefore, the primary is likely to be the product of a stellar merger, with the estimated age of the primary corresponding only to the time elapsed since the merger.[3]
Mass estimates for the two stars remain disparate. Using speckle interferometry, McAlister (1982) obtained mass estimates of 4.73 solar masses (4.73 M☉) for the primary and 2.75 M☉ for the secondary. He noted that the mass estimate was too high for the given classification of the primary.[17] 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.[18] Prieto and Lambert (1999) came up with a mass estimate of 3.81 M☉ for the primary,[19] while Pizzolato and Maggio (2000) obtained 4.34 M☉.[8] Ling et al. (2001) obtained estimates of 2.7 M☉ for the primary and 1.65 M☉ for the secondary,[9] while Kaler (2001) obtained 2.5 and 1.9, respectively.[14] Diamant et al. (2023) found masses of 3.6 and 2.4 M☉ for A and B respectively.[10]
Name and etymology
- This star, together with δ Per, ψ Per, σ Per, α Per and η Per, has been called the Segment of Perseus.[20]
- In Chinese, 天船 (Tiān Chuán), meaning Celestial Boat, refers to an asterism consisting of γ Persei, η Persei, α Persei, ψ Persei, δ Persei, 48 Persei, μ Persei and HD 27084. Consequently, the Chinese name for γ Persei itself is 天船二 (Tiān Chuán èr, English: the Second Star of Celestial Boat.)[21]
References
- ^ 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.
- ^ 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
- ^ a b c d Tarczay-Nehéz, D.; Molnár, L.; Ádám, R. (2026-01-31), "What's Their Age Again? A Blue-Straggler Merger Scenario in the γ Persei Binary System", arXiv:2602.00896 [astro-ph.SR]
- ^ 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.
- ^ 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.
- ^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Washington, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W
- ^ 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.
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ a b Kaler, James B. (January 5, 2001), "GAMMA PER (Gamma Persei)", Stars, University of Illinois, retrieved 2012-02-25
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ Allende Prieto, C.; Lambert, D. L. (December 1999), "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures", Astronomy and Astrophysics, 352: 555–562, Bibcode:1999A&A...352..555A, ISSN 0004-6361
- ^ 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.
{{cite book}}: ISBN / Date incompatibility (help) - ^ (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
