Gamma Columbae is a possible wide binary star system[3] 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.[6] Based upon an annual parallax shift of 3.09 mas,[2] 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.[8]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba[1] |
| Right ascension | 05h 57m 32.210s[2] |
| Declination | −35° 16′ 59.81″[2] |
| Apparent magnitude (V) | 4.366 + 12.664[3] |
| Characteristics | |
| Spectral type | B2.5 IV[4] + G8 V[5] |
| U−B color index | −0.66[6] |
| B−V color index | −0.18[6] |
| Variable type | Candidate SPB[7] |
| Astrometry | |
| Radial velocity (Rv) | +24.2±0.7[8] km/s |
| Proper motion (μ) | RA: −2.652 mas/yr[2] Dec.: +10.218 mas/yr[2] |
| Parallax (π) | 3.0918±0.1241 mas[2] |
| Distance | 1,050 ± 40 ly (320 ± 10 pc) |
| Absolute magnitude (MV) | −2.76[1] |
| Details[7] | |
| γ Col A | |
| Mass | 5.7±0.3 M☉ |
| Radius | 4.8±0.4 R☉ |
| Luminosity | 2,070[9] L☉ |
| Surface gravity (log g) | 3.328±0.100[10] cgs |
| Temperature | 15570±320[10] K |
| Rotational velocity (v sin i) | 96±16 km/s |
| Age | 23.6±2.0[11] Myr |
| γ Col B | |
| Mass | 0.94[3] M☉ |
| Temperature | 5,367[3] K |
| Other designations | |
| γ Col, CD−35°2612, HD 40494, HIP 28199, HR 2106, SAO 196352[12] | |
| Database references | |
| SIMBAD | data |
The primary component is an evolved[7] B-type subgiant star with a stellar classification of B2.5 IV.[4] It is a candidate slowly pulsating B-type star with a mean longitudinal magnetic field strength of 94±28 G.[7] The star has nearly six times the mass of the Sun and close to five times the Sun's girth.[7] It is radiating over 2,000 times the solar luminosity from its outer atmosphere at an effective temperature of 12,904 K.[9] The star has a high rate of spin, showing a projected rotational velocity of around 96 km/s.[7]
The estimated age of this star is around 24 million years.[11] 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.[10]
The visual magnitude 12.664[3] co-moving companion is a G-type main sequence star with a classification of G8 V.[5] 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.[3] Despite the young age of these stars, there has been no X-ray emission detected.[3]
References
edit- 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
edit- Kaler, James B. (January 29, 2016), "Gamma Columbae", STARS, University of Illinois, retrieved 2016-12-21.