Summary
FN Canis Majoris is a binary star[4] system in the southern constellation Canis Major, near the northern constellation border with Monoceros. It is dimly visible to the naked eye with a combined apparent visual magnitude of 5.41.[3] The system is located at a distance of approximately 3,000 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +31 km/s.[3] It is a runaway star associated with the Sh 2-296 nebula in the CMa OB1 association, and has a conspicuous bow-shock feature.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 06m 40.76672s[2] |
| Declination | −11° 17′ 38.4396″[2] |
| Apparent magnitude (V) | 5.41[3] (5.69 + 7.04)[4] |
| Characteristics | |
| Spectral type | B0 III/IV[5] or B2 Ia/ab[6] |
| B−V color index | 0.033±0.004[3] |
| Astrometry | |
| Radial velocity (Rv) | +31.0±4.2[3] km/s |
| Proper motion (μ) | RA: −3.14±0.72[2] mas/yr Dec.: +3.32±0.55[2] mas/yr |
| Parallax (π) | 1.07 ± 0.61 mas[2] |
| Distance | approx. 3,000 ly (approx. 900 pc) |
| Details | |
| Mass | 19.23±1.85,[7] 24.0±0.1,[8] 35.5±4.6[9] M☉ |
| Luminosity (bolometric) | 122,079,[7] 690,000[9] L☉ |
| Surface gravity (log g) | 3.59±0.11[9] cgs |
| Temperature | 26,850,[7] 33,600±1,840[9] K |
| Rotational velocity (v sin i) | 100±9[9] km/s |
| Age | 6.0±0.1[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The brighter component is a visual magnitude 5.69[4] B-type star that has been assigned various stellar classification from B0 III/IV[5] to B2 Ia/ab,[6] suggesting it is an evolved state. In the past it was classified as a Beta Cephei type variable star[11] with an apparent magnitude that was measured varing between +5.38 and +5.42 over a period of 36.7 hours,[12] but is no longer considered to be one.[13] This is a massive star with estimates ranging from 19[7] to 36[9] times the mass of the Sun, and luminosity estimates of 122,079[7] to 690,000[9] times the Sun's luminosity. The magnitude 7.04[4] companion is located at an angular separation of 0.60″ from the primary at a position angle of 111°, as of 2003.[14]
References edit
- ^ Rivinius, Th.; Stahl, O.; Štefl, S.; Baade, D.; Townsend, R. H. D.; Barrera, L. (July 2011). "The (B0+?)+O6 system FN CMa: a case for tidal-pulsational interaction?". Proceedings IAU Symposium. 272: 543–544. arXiv:1009.3512. Bibcode:2011IAUS..272..543R. doi:10.1017/S1743921311011380.
- ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c d e 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.
- ^ a b c d Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ a b Tjin A Djie, H. R. E.; et al. (August 2001). "The stellar composition of the star formation region CMa R1 - II. Spectroscopic and photometric observations of nine young stars". Monthly Notices of the Royal Astronomical Society. 325 (4): 1441–1457. arXiv:astro-ph/0103349. Bibcode:2001MNRAS.325.1441T. doi:10.1046/j.1365-8711.2001.04541.x. S2CID 117112792.
- ^ a b c Fernandes, B.; et al. (August 2019). "Runaways and shells around the CMa OB1 association". Astronomy & Astrophysics. 628: 15. arXiv:1906.00113. Bibcode:2019A&A...628A..44F. doi:10.1051/0004-6361/201935484. S2CID 173990935. A44.
- ^ a b c d e Hohle, M. M.; et al. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten. 331 (4): 349–360. arXiv:1003.2335. Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. S2CID 111387483.
- ^ a b Tetzlaff, N.; et al. (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
- ^ a b c d e f g Zorec, J.; et al. (November 2016). "Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity". Astronomy & Astrophysics. 595: 26. Bibcode:2016A&A...595A.132Z. doi:10.1051/0004-6361/201628760. hdl:11336/37946.
- ^ "FN CMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-03-09.
- ^ Hill, Graham (1967). "On Beta Cephei Stars: a Search for Beta Cephei Stars". The Astrophysical Journal Supplement Series. 14: 263. Bibcode:1967ApJS...14..263H. doi:10.1086/190156. ISSN 0067-0049.
- ^ Lefèvre, L.; Marchenko, S. V.; Moffat, A. F. J.; Acker, A. (2009). "A systematic study of variability among OB-stars based on HIPPARCOS photometry" (PDF). Astronomy and Astrophysics. 507 (2): 1141–1201. Bibcode:2009A&A...507.1141L. doi:10.1051/0004-6361/200912304. ISSN 0004-6361.
- ^ Stankov, Anamarija; Handler, Gerald (2005). "Catalog of Galactic β Cephei Stars". The Astrophysical Journal Supplement Series. 158 (2): 193–216. arXiv:astro-ph/0506495. Bibcode:2005ApJS..158..193S. doi:10.1086/429408. ISSN 0067-0049. S2CID 119526948.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.