Astronomy:12 Canis Majoris
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 47m 01.48353s[2] |
| Declination | −21° 00′ 55.4517″[2] |
| Apparent magnitude (V) | +6.07[3] |
| Characteristics | |
| Spectral type | B7 II/III[4] or B5 V[5] |
| B−V color index | −0.159±0.004[3] |
| Variable type | SX Ari[6] |
| Astrometry | |
| Radial velocity (Rv) | +16.4±2.5[3] km/s |
| Proper motion (μ) | RA: −14.568[2] mas/yr Dec.: +5.778[2] mas/yr |
| Parallax (π) | 4.6155 ± 0.0543 mas |
| Distance | 707 ± 8 ly (217 ± 3 pc) |
| Absolute magnitude (MV) | −0.81[3] |
| Details | |
| Mass | 4.8[7] M☉ |
| Radius | 2.73[8] R☉ |
| Luminosity | 537[9] L☉ |
| Surface gravity (log g) | 4.23[5] cgs |
| Temperature | 15,830±60[9] K |
| Metallicity [Fe/H] | −0.37[10] dex |
| Rotation | 2.18045 d[7] |
| Rotational velocity (v sin i) | 65[7] km/s |
| Age | 134[11] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
12 Canis Majoris is a variable star located about 707 light years away from the Sun in the southern constellation of Canis Major.[12] It has the variable star designation HK Canis Majoris; 12 Canis Majoris is the Flamsteed designation. This body is just barely visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of +6.07.[3] It is moving away from the Earth with a heliocentric radial velocity of +16 km/s.[3] This is the brightest star in the vicinity of the open cluster NGC 2287,[13] although it is probably not a member based on its proper motion.[14]
This star has a stellar classification of B7 II/III,[4] matching the spectrum of a B-type star intermediate between a giant and bright giant.[4] (Cidale et al. (2007) show a class of B5 V,[5] which would indicate it is instead a B-type main-sequence star.) It is a magnetic Bp star[15] of the helium–weak variety (CP4), with the spectrum displaying evidence for vertical stratification of helium in the atmosphere.[16] Samus et al. (2017) classify it as an SX Arietis variable that varies in brightness by about 0.05 magnitudes over a period of 2.18045 days.[6] It has 4.8 times the mass of the Sun and 2.73[8] times the Sun's radius. The star is radiating 537 times the Sun's luminosity from its photosphere at an effective temperature of 15,830 K.
References
- ↑ Bernhard, Klaus; Hũmmerich, Stefan; Paunzen, Ernst (17 February 2020). "New and improved rotational periods of magnetic CP stars from ASAS-3, KELT, and MASCARA data". Monthly Notices of the Royal Astronomical Society 493 (3): 3293–3330. doi:10.1093/mnras/staa462. Bibcode: 2020MNRAS.493.3293B.
- ↑ 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 4.0 4.1 4.2 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H.
- ↑ 5.0 5.1 5.2 Cidale, L. S. et al. (June 2007), "Fundamental parameters of He-weak and He-strong stars", Astronomy and Astrophysics 468 (1): 263–272, doi:10.1051/0004-6361:20066454, Bibcode: 2007A&A...468..263C.
- ↑ 6.0 6.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ 7.0 7.1 7.2 Shultz, M. E.; Owocki, S. P.; Ud-Doula, A.; Biswas, A.; Bohlender, D.; Chandra, P.; Das, B.; David-Uraz, A. et al. (2022). "MOBSTER - VI. The crucial influence of rotation on the radio magnetospheres of hot stars". Monthly Notices of the Royal Astronomical Society 513 (1): 1429. doi:10.1093/mnras/stac136. Bibcode: 2022MNRAS.513.1429S.
- ↑ 8.0 8.1 Shulyak, D. et al. (2014), "Interferometry of chemically peculiar stars: Theoretical predictions versus modern observing facilities", Monthly Notices of the Royal Astronomical Society 443 (2): 1629, doi:10.1093/mnras/stu1259, Bibcode: 2014MNRAS.443.1629S.
- ↑ 9.0 9.1 Netopil, M. et al. (November 2008), "Chemically peculiar stars and their temperature calibration", Astronomy and Astrophysics 491 (2): 545–554, doi:10.1051/0004-6361:200810325, Bibcode: 2008A&A...491..545N.
- ↑ Mosser, B. et al. (February 2005), "Seismology and activity of the F type star HD 49933", Astronomy and Astrophysics 431 (2): L13–L16, doi:10.1051/0004-6361:200500003, Bibcode: 2005A&A...431L..13M.
- ↑ Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771–782. doi:10.1134/S1063773712120031. ISSN 1063-7737. Bibcode: 2012AstL...38..771G.
- ↑ 12.0 12.1 "12 CMa". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=12+CMa.
- ↑ Feinstein, A. et al. (1979), "Multicolor photometry of the open cluster NGC 2287", International Astronomical Union, Reunion Astronomica Regional Latinoamericana, 1st, Santiago, Chile, Jan. 16-21, 1978, 3, Chile, Universidad: Departamento de Astronomia, Publicaciones, pp. 146–149, Bibcode: 1979rarl.conf..146F.
- ↑ Levato, H.; Garcia, B. (1984), "Axial rotation in NGC 2287", Astrophysical Letters 24 (3): 161–164, Bibcode: 1984ApL....24..161L.
- ↑ Bailey, J. D.; Landstreet, J. D. (2013), "Abundances determined using Si ii and Si iii in B-type stars: Evidence for stratification", Astronomy & Astrophysics 551: A30, doi:10.1051/0004-6361/201220671, Bibcode: 2013A&A...551A..30B.
- ↑ Farthmann, M. et al. (November 1994), "Stratification of helium in the photospheres of the helium-weak stars HD 28843 and HD 49333", Astronomy and Astrophysics 291: 919–927, Bibcode: 1994A&A...291..919F.
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