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. The brightness of the star was found to be variable when the Hipparcos data was analyzed. It was given its variable star designation in 1999.[11] 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.
- ↑ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars 4659: 1-27. Bibcode: 1999IBVS.4659....1K. https://ibvs.konkoly.hu/pub/ibvs/4601/4659.pdf. Retrieved 1 January 2025.
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