9 Cassiopeiae (9 Cas) is a white giant star in the constellation Cassiopeia, about 2,370 light years away.
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 00h 04m 13.6625s[1] |
| Declination | +62° 17′ 15.591″[1] |
| Apparent magnitude (V) | +5.884[2] |
| Characteristics | |
| Spectral type | A1II-III[3] |
| U−B color index | +0.29[4] |
| B−V color index | +0.30[4] |
| Astrometry | |
| Radial velocity (Rv) | −23.43±0.16[1] km/s |
| Proper motion (μ) | RA: −0.936[1] mas/yr Dec.: −0.263[1] mas/yr |
| Parallax (π) | 1.3781 ± 0.0237 mas[1] |
| Distance | 2,370 ± 40 ly (730 ± 10 pc) |
| Details | |
| Mass | 5.1[5] M☉ |
| Radius | 26[6] R☉ |
| Luminosity | 2,208[6] L☉ |
| Surface gravity (log g) | 2.08[5] cgs |
| Temperature | 7,719[6] K |
| Metallicity [Fe/H] | −0.32[5] dex |
| Rotational velocity (v sin i) | 33[7] km/s |
| Age | 25.1[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
9 Cassiopeiae is classified as an A1 type giant or bright giant. One study noted peculiarities in the spectrum that could indicate a λ Boötis star,[9] but other researchers have refuted this.[10][7]
At an age of 25 million years, 9 Cassiopeiae has expanded away from the main sequence after exhausting its core hydrogen and now has a radius about 26 times that of the Sun. With an effective temperature of about 7,700 K, it emits more than two thousand times the luminosity of the Sun.
9 Cassiopeiae has a number of faint companions listed in multiple star catalogues,[11] but they all appear to be at different distances[12] and none are thought to be gravitationally associated.[13]
References
edit- ^ a b c d e f 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.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (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.
- ^ Gray, R. O.; Garrison, R. F. (December 1987). "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". Astrophysical Journal Supplement. 65: 581. Bibcode:1987ApJS...65..581G. doi:10.1086/191237.
- ^ a b Hoffleit, D.; Jaschek, C., eds. (1991). The Bright Star Catalogue. New Haven: Yale University Observatory. Bibcode:1991bsc..book.....H.
- ^ a b c Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. (2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy and Astrophysics. 628: A94. arXiv:1904.11302. Bibcode:2019A&A...628A..94A. doi:10.1051/0004-6361/201935765. S2CID 131780028.
- ^ a b c 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.
- ^ a b Murphy, Simon J.; Corbally, Christopher J.; Gray, Richard O.; Cheng, Kwang-Ping; Neff, James E.; Koen, Chris; Kuehn, Charles A.; Newsome, Ian; Riggs, Quinlin (2015). "An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue". Publications of the Astronomical Society of Australia. 32. arXiv:1508.03633. Bibcode:2015PASA...32...36M. doi:10.1017/pasa.2015.34. S2CID 59405545.
- ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (October 12, 2010). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1). Oxford University Press (OUP): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711.
- ^ Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
- ^ Hauck, B.; Ballereau, D.; Chauville, J. (1998). "New lambda Bootis stars with a shell". Astronomy and Astrophysics Supplement Series. 128 (3): 429. arXiv:astro-ph/9709015. Bibcode:1998A&AS..128..429H. doi:10.1051/aas:1998154. S2CID 118881330.
- ^ Mason, Brian D.; et al. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.
- ^ 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.
- ^ Eggleton, P. P.; Tokovinin, A. A. (3 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.