Astronomy:FR Canis Majoris
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 21m 24.72s[1] |
| Declination | −11° 46′ 23.7″[1] |
| Apparent magnitude (V) | 5.43 - 5.64[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B1.5IVe[4] |
| Astrometry | |
| Radial velocity (Rv) | +16[4] km/s |
| Proper motion (μ) | RA: −2.273[1] mas/yr Dec.: +1.193[1] mas/yr |
| Parallax (π) | 1.8635 ± 0.0597[1] mas |
| Distance | 1,750 ± 60 ly (540 ± 20 pc) |
| Absolute magnitude (MV) | −2.7[5] |
| Details | |
| Mass | 10.7[6] M☉ |
| Radius | 7.9[1] R☉ |
| Luminosity | 11,194[6] L☉ |
| Surface gravity (log g) | 3.97[1] cgs |
| Temperature | 23,878[6] K |
| Rotation | 0.924 days[7] |
| Rotational velocity (v sin i) | 232[7] km/s |
| Age | 14.5[3] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
FR Canis Majoris (FR CMa) is a blue-white main sequence star located in the constellation of Canis Major. According to the new reduction of parallax data from the Hipparcos satellite, it is located approximately 1,750 light-years from the solar system.[8]
Observations
FR Canis Majoris is a blue-white main-sequence star of spectral type B1.5IVe. With an effective temperature of 23,878 K, its luminosity is over 10,000 times greater than that of the Sun. It rotates with a projected rotational velocity, the lower limit of its real equatorial rotation speed, of 232 km/s, its rotational axis being inclined at 48° with respect to the observer on Earth. It has a mass of about 11 solar masses, thus being above the limit beyond which stars violently end their lives by exploding as supernovae. Its age is estimated at 14.5 million years, which represents 83% of its main-sequence life.[3] It is a Be star and also a Gamma Cassiopeiae variable, eruptive variables that show irregular variations in their luminosity caused by the expulsion of matter with a variation amplitude of 0.116 magnitudes.[9][10][11]
It has an absolute magnitude of −2.7 and its positive radial velocity indicates that the star is moving away from the solar system.[12]
Companion
FR Canis Majoris has a magnitude 9.7 companion, 4.2 arcseconds distant and with a position angle of 23 degrees, which may actually be gravitationally bound to it. Another star of 11th magnitude is 56.5 arcseconds distant, but it may only be in the line of sight to Earth and is not bound to the main star.[13]
Reference
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.
- ↑ "FR CMa". AAVSO. https://vsx.aavso.org/index.php?view=detail.top&oid=18831.
- ↑ 3.0 3.1 3.2 Zorec, J.; Frémat, Y.; Cidale, L. (2005). "On the evolutionary status of be stars. I. Field be stars near the Sun". Astronomy and Astrophysics 441 (1): 235. doi:10.1051/0004-6361:20053051. Bibcode: 2005A&A...441..235Z.
- ↑ 4.0 4.1 4.2 "FR Canis Majoris". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=FR+Canis+Majoris.
- ↑ Melnik, A. M.; Dambis, A. K. (2020). "Distance scale for high-luminosity stars in OB associations and in field with Gaia DR2. Spurious systematic motions". Astrophysics and Space Science 365 (7): 112. doi:10.1007/s10509-020-03827-0. Bibcode: 2020Ap&SS.365..112M.
- ↑ 6.0 6.1 6.2 Quintana, Alexis L.; Wright, Nicholas J.; Martínez García, Juan (2025). "A census of OB stars within 1 KPC and the star formation and core collapse supernova rates of the Milky Way". Monthly Notices of the Royal Astronomical Society 538 (3): 1367. doi:10.1093/mnras/staf083. Bibcode: 2025MNRAS.538.1367Q.
- ↑ 7.0 7.1 Balona, Luis A.; Ozuyar, Dogus (2021). "TESS Observations of be Stars: General Characteristics and the Impulsive Magnetic Rotator Model". The Astrophysical Journal 921 (1): 5. doi:10.3847/1538-4357/ac1a77. Bibcode: 2021ApJ...921....5B.
- ↑ "FR Canis Majoris". http://www.alcyone.de/cgi-bin/search.pl?object=HR2284.
- ↑ "VSX : Detail for FR CMa". https://vsx.aavso.org/index.php?view=detail.top&oid=5334.
- ↑ Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (April 2010). "Masses and luminosities of O- and B-type stars and red supergiants" (in en). Astronomische Nachrichten 331 (4): 349–360. doi:10.1002/asna.200911355. ISSN 0004-6337.
- ↑ Frémat, Y.; Zorec, J.; Hubert, A.-M.; Floquet, M. (2005-09-01). "Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars" (in en). Astronomy & Astrophysics 440 (1): 305–320. doi:10.1051/0004-6361:20042229. ISSN 0004-6361.
- ↑ Lefèvre, L.; Marchenko, S. V.; Moffat, A. F. J.; Acker, A. (2009-11-01). "A systematic study of variability among OB-stars based on HIPPARCOS photometry" (in en). Astronomy & Astrophysics 507 (2): 1141–1201. doi:10.1051/0004-6361/200912304. ISSN 0004-6361.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (2008-09-11). "A catalogue of multiplicity among bright stellar systems" (in en). Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x.
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