  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 31m 51.36636s [1] |
| Declination | −23° 25′ 06.3181″ [1] |
| Apparent magnitude (V) | 4.33 – 4.36 [2] |
| Characteristics | |
| Spectral type | B1 III [3] |
| U−B color index | −0.98 [4] |
| B−V color index | −0.24 [4] |
| Variable type | β Cep [3] |
| Astrometry | |
| Radial velocity (Rv) | +26.9 [5] km/s |
| Proper motion (μ) |
RA: −2.91
[1]
mas/
yr Dec.: +6.22 [1] mas/ yr |
| Parallax (π) | 2.36 ± 0.20 mas [1] |
| Distance | 1,400 ± 100
ly (420 ± 40 pc) |
| Absolute magnitude (MV) | −3.86 [6] |
| Details | |
| Mass | 14.2±0.4 [6] M☉ |
| Radius | 7.9±0.6 [6] R☉ |
| Luminosity | 30,900+8,900 −6,900 [6] L☉ |
| Surface gravity (log g) | 3.78±0.07 [6] cgs |
| Temperature | 27,000±1,000 [6] K |
| Metallicity [Fe/H] | −0.18 [7] dex |
| Rotational velocity (v sin i) | 0 [6] km/s |
| Age | 11.1±0.7 [6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Xi1 Canis Majoris, Latinized from ξ1 Canis Majoris, is a Beta Cephei variable star in the constellation Canis Major. It is approximately 1,400 light years from Earth.
ξ1 Canis Majoris is a blue-white B-type star. It has generally been assigned a luminosity class of III ( giant) or IV ( subgiant), for example B1III [3] or B0.5IV. [6] Comparison of its properties with model evolutionary tracks suggest that it is a main sequence star about three quarters of the way through its main sequence lifetime. [6]
The apparent magnitude varies from +4.33 to +4.36 with a period of 5.03 hours. [2] Its pulsations cause its radius to vary by 1.0% to 1.5%. At the same time its effective temperature by about 500 K above and below its mean temperature. [6]
ξ1 Canis Majoris has the longest known rotation period of any B class star, taking around 30 years to complete one revolution on its axis. [9] This is thought to be due to magnetic braking; ξ1 Canis Majoris has the strongest magnetic field of any β Cephei star and would be expected to spin down completely in around four million years. It also has the strongest and hardest X-ray emission of any β Cephei star. [6]
ξ1 Canis Majoris forms a naked eye pairing with ξ2 Canis Majoris a little less than a degree away. The Washington Double Star Catalog lists two 14th magnitude companions about 27 ″ away. [10] In addition, an unseen close companion is suspected due to some faint emission lines in the spectrum that are best explained by a Be star invisible against the brighter primary. [6]
- ^ 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 "International Variable Star Index". Retrieved 2018-11-13.
- ^ a b c Hubrig, S.; et al. (January 2009). "New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars". Astronomische Nachrichten. 330 (4): 317. arXiv: 0902.1314. Bibcode: 2009AN....330..317H. doi: 10.1002/asna.200811187. S2CID 17497112.
- ^ a b Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode: 1966CoLPL...4...99J.
- ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. Determination of Radial Velocities and Their Applications. Vol. 30. p. 57. Bibcode: 1967IAUS...30...57E.
- ^ a b c d e f g h i j k l m Shultz, M.; Wade, G. A.; Rivinius, Th.; Neiner, C.; Henrichs, H.; Marcolino, W.; MiMeS Collaboration (2017). "The pulsating magnetosphere of the extremely slowly rotating magnetic β Cep star ξ1 CMa". Monthly Notices of the Royal Astronomical Society. 471 (2): 2286. arXiv: 1706.08820. Bibcode: 2017MNRAS.471.2286S. doi: 10.1093/mnras/stx1632.
- ^ 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.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 20 August 2022.
- ^ Shultz, M.; Kochukhov, O.; Wade, G. A.; Rivinius, Th (2018). "The pulsationally modulated radial crossover signature of the slowly rotating magnetic B-type star ξ1 CMa". Monthly Notices of the Royal Astronomical Society. 478 (1): L39. arXiv: 1804.07535. Bibcode: 2018MNRAS.478L..39S. doi: 10.1093/mnrasl/sly070.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode: 2001AJ....122.3466M. doi: 10.1086/323920.
| Stars |
| ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
|
Star clusters |
| ||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||
| |||||||||||||
| |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 31m 51.36636s [1] |
| Declination | −23° 25′ 06.3181″ [1] |
| Apparent magnitude (V) | 4.33 – 4.36 [2] |
| Characteristics | |
| Spectral type | B1 III [3] |
| U−B color index | −0.98 [4] |
| B−V color index | −0.24 [4] |
| Variable type | β Cep [3] |
| Astrometry | |
| Radial velocity (Rv) | +26.9 [5] km/s |
| Proper motion (μ) |
RA: −2.91
[1]
mas/
yr Dec.: +6.22 [1] mas/ yr |
| Parallax (π) | 2.36 ± 0.20 mas [1] |
| Distance | 1,400 ± 100
ly (420 ± 40 pc) |
| Absolute magnitude (MV) | −3.86 [6] |
| Details | |
| Mass | 14.2±0.4 [6] M☉ |
| Radius | 7.9±0.6 [6] R☉ |
| Luminosity | 30,900+8,900 −6,900 [6] L☉ |
| Surface gravity (log g) | 3.78±0.07 [6] cgs |
| Temperature | 27,000±1,000 [6] K |
| Metallicity [Fe/H] | −0.18 [7] dex |
| Rotational velocity (v sin i) | 0 [6] km/s |
| Age | 11.1±0.7 [6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Xi1 Canis Majoris, Latinized from ξ1 Canis Majoris, is a Beta Cephei variable star in the constellation Canis Major. It is approximately 1,400 light years from Earth.
ξ1 Canis Majoris is a blue-white B-type star. It has generally been assigned a luminosity class of III ( giant) or IV ( subgiant), for example B1III [3] or B0.5IV. [6] Comparison of its properties with model evolutionary tracks suggest that it is a main sequence star about three quarters of the way through its main sequence lifetime. [6]
The apparent magnitude varies from +4.33 to +4.36 with a period of 5.03 hours. [2] Its pulsations cause its radius to vary by 1.0% to 1.5%. At the same time its effective temperature by about 500 K above and below its mean temperature. [6]
ξ1 Canis Majoris has the longest known rotation period of any B class star, taking around 30 years to complete one revolution on its axis. [9] This is thought to be due to magnetic braking; ξ1 Canis Majoris has the strongest magnetic field of any β Cephei star and would be expected to spin down completely in around four million years. It also has the strongest and hardest X-ray emission of any β Cephei star. [6]
ξ1 Canis Majoris forms a naked eye pairing with ξ2 Canis Majoris a little less than a degree away. The Washington Double Star Catalog lists two 14th magnitude companions about 27 ″ away. [10] In addition, an unseen close companion is suspected due to some faint emission lines in the spectrum that are best explained by a Be star invisible against the brighter primary. [6]
- ^ 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 "International Variable Star Index". Retrieved 2018-11-13.
- ^ a b c Hubrig, S.; et al. (January 2009). "New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars". Astronomische Nachrichten. 330 (4): 317. arXiv: 0902.1314. Bibcode: 2009AN....330..317H. doi: 10.1002/asna.200811187. S2CID 17497112.
- ^ a b Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode: 1966CoLPL...4...99J.
- ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. Determination of Radial Velocities and Their Applications. Vol. 30. p. 57. Bibcode: 1967IAUS...30...57E.
- ^ a b c d e f g h i j k l m Shultz, M.; Wade, G. A.; Rivinius, Th.; Neiner, C.; Henrichs, H.; Marcolino, W.; MiMeS Collaboration (2017). "The pulsating magnetosphere of the extremely slowly rotating magnetic β Cep star ξ1 CMa". Monthly Notices of the Royal Astronomical Society. 471 (2): 2286. arXiv: 1706.08820. Bibcode: 2017MNRAS.471.2286S. doi: 10.1093/mnras/stx1632.
- ^ 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.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 20 August 2022.
- ^ Shultz, M.; Kochukhov, O.; Wade, G. A.; Rivinius, Th (2018). "The pulsationally modulated radial crossover signature of the slowly rotating magnetic B-type star ξ1 CMa". Monthly Notices of the Royal Astronomical Society. 478 (1): L39. arXiv: 1804.07535. Bibcode: 2018MNRAS.478L..39S. doi: 10.1093/mnrasl/sly070.
- ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode: 2001AJ....122.3466M. doi: 10.1086/323920.
| Stars |
| ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
|
Star clusters |
| ||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||
| |||||||||||||