Gamma Columbae
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 05h 57m 32.210s |
| Declination | −35° 16′ 59.81″ |
| Apparent magnitude (V) | 4.366 + 12.664 |
| Characteristics | |
| Spectral type | B2.5 IV + G8 V |
| U−B color index | −0.66 |
| B−V color index | −0.18 |
| Variable type | Candidate SPB |
| Astrometry | |
| Radial velocity (Rv) | +24.2±0.7 km/s |
| Proper motion (μ) | RA: −2.652 mas/yr Dec.: +10.218 mas/yr |
| Parallax (π) | 3.0918±0.1241 mas |
| Distance | 1,050 ± 40 ly (320 ± 10 pc) |
| Absolute magnitude (MV) | −2.76 |
| Details | |
| γ Col A | |
| Mass | 5.7±0.3 M☉ |
| Radius | 4.8±0.4 R☉ |
| Luminosity | 2,070 L☉ |
| Surface gravity (log g) | 3.328±0.100 cgs |
| Temperature | 15570±320 K |
| Rotational velocity (v sin i) | 96±16 km/s |
| Age | 23.6±2.0 Myr |
| γ Col B | |
| Mass | 0.94 M☉ |
| Temperature | 5,367 K |
| Other designations | |
| γ Col, CD−35°2612, HD 40494, HIP 28199, HR 2106, SAO 196352 | |
| Database references | |
| SIMBAD | data |
Gamma Columbae is a possible wide binary star system in the southern constellation of Columba. Its name is a Bayer designation that is Latinized from γ Columbae, and abbreviated Gamma Col or γ Col. This system is visible to the naked eye as a point of light with an apparent visual magnitude of 4.36. Based upon an annual parallax shift of 3.09 mas, it is located at a distance of roughly 1,050 light-years (320 pc) from the Sun. The system is drifting further away with a line of ight velocity component of +24 km/s.
The primary component is an evolved B-type subgiant star with a stellar classification of B2.5 IV. It is a candidate slowly pulsating B-type star with a mean longitudinal magnetic field strength of 94±28 G. The star has nearly six times the mass of the Sun and close to five times the Sun's girth. It is radiating over 2,000 times the solar luminosity from its outer atmosphere at an effective temperature of 12,904 K. The star has a high rate of spin, showing a projected rotational velocity of around 96 km/s.
The estimated age of this star is around 24 million years. At this age, it is thought to be the remnant of a once more massive star that just finished hydrogen fusion, and is undergoing structural readjustment. This process is extremely short, on the order of ten thousand years, making it a rare object.
The visual magnitude 12.664 co-moving companion is a G-type main sequence star with a classification of G8 V. It lies at an angular separation of 33.8 arc seconds from the primary, which corresponds to a projected physical separation of 8,844 AU. Despite the young age of these stars, there has been no X-ray emission detected.
References
- 1 2 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. XHIP record for this object at VizieR.
- 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023), "Gaia Data Release 3. Summary of the content and survey properties", Astronomy and Astrophysics, 674: A1, arXiv:2208.00211, Bibcode:2023A&A...674A...1G, doi:10.1051/0004-6361/202243940, S2CID 244398875. Gaia DR3 record for this source at VizieR.
- 1 2 3 4 5 6 7 Gerbaldi, M.; et al. (November 2001), "Binary systems with post-T Tauri secondaries", Astronomy and Astrophysics, 379: 162–184, Bibcode:2001A&A...379..162G, doi:10.1051/0004-6361:20011298.
- 1 2 Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", Astrophysical Journal, 157: 313–326, Bibcode:1969ApJ...157..313H, doi:10.1086/150069.
- 1 2 Huélamo, N.; et al. (July 2000), "X-ray emission from Lindroos binary systems", Astronomy and Astrophysics, 359: 227–241, arXiv:astro-ph/0005348, Bibcode:2000A&A...359..227H.
- 1 2 3 Johnson, H. L.; et al. (1999), "UBVRIJKL photometry of the bright stars", Commission Lunar and Planetary Laboratory, 4: 99, Bibcode:1966CoLPL...4...99J.
- 1 2 3 4 5 6 Hubrig, S.; et al. (April 2009), "New magnetic field measurements of β 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.
- 1 2 Gontcharov, G. A. (2006), "Pulkovo compilation of radial velocities for 35495 stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- 1 2 McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
- 1 2 3 Irrgang, Andreas; et al. (2022), "γ Columbae as a recently stripped pulsating core of a massive star", Nature Astronomy, 6 (12): 1414–1420, arXiv:2211.00358, Bibcode:2022NatAs...6.1414I, doi:10.1038/s41550-022-01809-6, S2CID 253244604.
- 1 2 Tetzlaff, N.; et al. (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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ↑ "gam Col", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2016-12-19.
External links
- Kaler, James B. (January 29, 2016), "Gamma Columbae", STARS, University of Illinois, retrieved 2016-12-21.
