Astronomy:26 Canis Majoris
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 12m 12.21483s[2] |
| Declination | −25° 56′ 33.3107″[2] |
| Apparent magnitude (V) | 5.89[3] or (5.84 – 5.87)[4] |
| Characteristics | |
| Spectral type | B2 IV/V[5] |
| B−V color index | −0.170±0.004[6] |
| Variable type | SPB[4] |
| Astrometry | |
| Radial velocity (Rv) | +21.6±2.9[6] km/s |
| Proper motion (μ) | RA: −5.678[2] mas/yr Dec.: +8.929[2] mas/yr |
| Parallax (π) | 3.2442 ± 0.0841[2] mas |
| Distance | 1,010 ± 30 ly (308 ± 8 pc) |
| Absolute magnitude (MV) | −1.11[6] |
| Details | |
| Mass | 5.5±0.9[7] M☉ |
| Radius | 3.25[3] R☉ |
| Luminosity | 1,000+995 −499[7] L☉ |
| Surface gravity (log g) | 3.777±0.027[8] cgs |
| Temperature | 16,157±200[8] K |
| Rotation | 2.729±0.001[7] |
| Rotational velocity (v sin i) | 64±14[8] km/s |
| Age | 3.6±3.3[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
26 Canis Majoris is a variable star in the southern constellation of Canis Major,[10] located around 1,010 light years away from the Sun.[2] It has the variable star designation MM Canis Majoris; 26 Canis Majoris is the Flamsteed designation.[10] This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of 5.89.[3] It is moving further from the Earth with a heliocentric radial velocity of +22 km/s.[6]
With a stellar classification of B2 IV/V,[5] it appears as a B-type main-sequence star intermixed with traits of an evolving subgiant star. Samus et al. (2017) classify it as a slowly pulsating B-type variable star (SPB), which ranges from magnitude 5.84 down to 5.87 with a rotationally-modulated period of 2.72945 days.[4] Briquet et al. (2007) describe it as a chemically peculiar He-variable star, having inhomogeneous distributions of chemical elements across its surface. It has a variable, quasi-dipolar magnetic field, resulting in variations of the magnetic field and line strengths as it rotates.[7]
This star is around 3.6[9] million years old with a rotation period of 2.7 days.[7] It has 5.5[7] times the mass of the Sun and 3.25[3] times the Sun's radius. The star is radiating 1,000[7] times as much luminosity as the Sun from its photosphere at an effective temperature of 16,157 K.[8]
References
- ↑ Aerts, C.; De Cat, P.; Peeters, E.; Decin, L.; De Ridder, J.; Kolenberg, K.; Meeus, G.; Van Winckel, H. et al. (March 1999). "Selection of a sample of bright southern Slowly Pulsating B Stars for long-term photometric and spectroscopic monitoring". Astronomy & Astrophysics 343: 872–882. Bibcode: 1999A&A...343..872A. https://ui.adsabs.harvard.edu/abs/1999A&A...343..872A. Retrieved 15 November 2021.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 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.
- ↑ 4.0 4.1 4.2 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.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 6.2 6.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Briquet, M. et al. (January 2007), "Discovery of magnetic fields in three He variable Bp stars with He and Si spots", Astronomische Nachrichten 328 (1): 41–45, doi:10.1002/asna.200610702, Bibcode: 2007AN....328...41B.
- ↑ 8.0 8.1 8.2 8.3 Huang, W. et al. (2010), "A Stellar Rotation Census of B Stars: From ZAMS to TAMS", The Astrophysical Journal 722 (1): 605–619, doi:10.1088/0004-637X/722/1/605, Bibcode: 2010ApJ...722..605H.
- ↑ 9.0 9.1 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, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ 10.0 10.1 10.2 "26 CMa". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=26+CMa.
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