HD 7977
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cassiopeia[1] |
Right ascension | 01h 20m 31.596s[2] |
Declination | +61° 52′ 57.01″[2] |
Apparent magnitude (V) | 9.04[3] |
Characteristics | |
Evolutionary stage | main sequence[2] |
Spectral type | G3[4] |
Astrometry | |
Proper motion (μ) | RA: +0.144[2] mas/yr Dec.: +0.010[2] mas/yr |
Parallax (π) | 13.2118±0.0322 mas[2] |
Distance | 246.9 ± 0.6 ly (75.7 ± 0.2 pc) |
Details | |
Mass | 1.07[2] M☉ |
Radius | 1.09[2] R☉ |
Luminosity | 1.20[2] L☉ |
Surface gravity (log g) | 4.35[2] cgs |
Temperature | 5,816[2] K |
Metallicity [Fe/H] | −0.59[2] dex |
Age | 6.7[2] Gyr |
Other designations | |
HD 7977, BD+61°250, SAO 11703 | |
Database references | |
SIMBAD | data |
HD 7977 is a G-type main-sequence star located in the constellation of Cassiopeia, around 246.9 light-years away from Earth. HD 7977 is notable for its uncertain[5] close flyby of the Solar System 2.47 million years ago, when it is predicted to have come as close as 3,800 astronomical units or less, although there are reasons to doubt the proper motions used to compute this flyby.[5] For comparison, Proxima Centauri is roughly 270,000 au from Earth. Its flyby may have taken it close enough to the Sun that it penetrated deep into the Oort Cloud and disturbed the population of Oort Cloud bodies and long-period comets there.[6] Its mass is equivalent to 1.07 times the Sun's mass.[7]

References
- ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
- ^ a b c d e f g h i j k l m 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.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27 – L30. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
- ^ Schwassmann, Arnold; Van Rhijn, P. J. (1935). "Bergedorfer Spektral-Durchmusterung der 115 noerdlichen Kapteynschen Eichfelder - Bd.1: Eichfeld 1 bis 19, Deklination +90 deg., +75 deg., +60 deg". Bergedorf: Hamburger Sternwarte. Bibcode:1935bsdn.book.....S.
- ^ a b Dybczyński, Piotr A.; Królikowska, Małgorzata; Bartczak, Przemysław; Podlewska-Gaca, Edyta; Kamiński, Krzysztof; Tokarek, Jakub; Langner, Krzysztof; Bruijne, Jos de (2024-05-01). "HD 7977 and its possible influence on Solar System bodies". Astronomy & Astrophysics. 685: A171. doi:10.1051/0004-6361/202348995. hdl:10045/145544. ISSN 0004-6361.
- ^ Bobylev, V. V.; Bajkova, A. T. (2022). "Search for Close Stellar Encounters with the Solar System Based on Data from the Gaia DR3 Catalogue". Astronomy Letters. 48 (9): 542. arXiv:2206.14443. Bibcode:2022AstL...48..542B. doi:10.1134/S1063773722080011. S2CID 256832377.
- ^ de la Fuente Marcos, Raúl; de la Fuente Marcos, Carlos (2022). "The Closest Past Flyby of a Known Star to the Solar System: HD 7977, UCAC4 237-008148 or WISE J072003.20-084651.2?". Research Notes of the American Astronomical Society. 6 (7): 152. Bibcode:2022RNAAS...6..152D. doi:10.3847/2515-5172/ac842b.