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Theta2 Crucis 
Summary
Theta2 Crucis, Latinized from θ2 Crucis, is a spectroscopic binary star in the constellation Crux. This pair of stars complete an orbit every 3.4280 days and they have a low orbital eccentricity that is close to 0.0.[12] Theta2 Crucis is located at about 690 light-years from the Sun.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Crux |
| Right ascension | 12h 04m 19.22008s[2] |
| Declination | −63° 09′ 56.5167″[2] |
| Apparent magnitude (V) | 4.70 - 4.74[3] |
| Characteristics | |
| Spectral type | B3 V[4] |
| U−B color index | −0.61[5] |
| B−V color index | −0.08[5] |
| Variable type | β Cep[3] |
| Astrometry | |
| Radial velocity (Rv) | +16.3[6] km/s |
| Proper motion (μ) | RA: −18.467[2] mas/yr Dec.: +0.467[2] mas/yr |
| Parallax (π) | 4.7314 ± 0.1276 mas[2] |
| Distance | 690 ± 20 ly (211 ± 6 pc) |
| Absolute magnitude (MV) | −2.35[7] |
| Orbit[8] | |
| Period (P) | 3.428 d |
| Eccentricity (e) | 0.00 |
| Periastron epoch (T) | 2419604.367 JD |
| Semi-amplitude (K1) (primary) | 51.3 km/s |
| Details | |
| Mass | 5.9[2] M☉ |
| Radius | 6.9[2] R☉ |
| Luminosity | 1,935[2] L☉ |
| Surface gravity (log g) | 3.55[2] cgs |
| Temperature | 15,361[2] K |
| Metallicity [Fe/H] | +0.20[2] dex |
| Rotational velocity (v sin i) | 23[9] km/s |
| Age | 18.5[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Since a member of the system is a β Cephei-type variable star, the magnitude is not fixed but varies slightly between +4.70 and +4.74. The period of this variability is 0.0889 days.[3] The system is categorized as is a blue-white B-type main sequence star with a stellar classification of B3 V,[4] although it has also been classified as a subgiant.[13] Evolutionary models show it at a late stage of its main sequence life.[2]
References edit
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 6 December 2022.
- ^ a b c d e f g h i j k l 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 Samus, N. N.; Durlevich, O. V.; et al. (January 2009). "General Catalogue of Variable Stars". VizieR. Retrieved 2010-05-19. Note: query for GCVS "tet 2 Cru".
- ^ a b Houk, N.; Cowley, A. P. (1975), University of Michigan Catalogue of two-dimensional spectral types for the HD stars, vol. 1, Bibcode:1975mcts.book.....H.
- ^ a b Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
- ^ Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Washington: Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
- ^ 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, S2CID 119257644.
- ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
- ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
- ^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873
- ^ "V* tet02 Cru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-05-19.
- ^ Batten, A. H. (1967). "Sixth catalogue of the orbital elements of spectroscopic binary systems". Publications of the Dominion Astrophysical Observatory, Victoria. 13: 154–155. Bibcode:1967PDAO...13..119B.
- ^ Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S.