Astronomy:Pi2 Columbae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 06h 07m 52.86009s[1] |
| Declination | −42° 09′ 14.5488″[1] |
| Apparent magnitude (V) | 5.50[2] |
| Characteristics | |
| Spectral type | A0 V + A[3] |
| B−V color index | +0.00[2] |
| Astrometry | |
| Radial velocity (Rv) | +31.0±3.7[4] km/s |
| Proper motion (μ) | RA: −10.612[1] mas/yr Dec.: −16.928[1] mas/yr |
| Parallax (π) | 12.8296 ± 0.1132[1] mas |
| Distance | 254 ± 2 ly (77.9 ± 0.7 pc) |
| Absolute magnitude (MV) | +1.17[5] |
| Details[6] | |
| Mass | 2.64 M☉ |
| Luminosity | 31[7] L☉ |
| Surface gravity (log g) | 4.38±0.14 cgs |
| Temperature | 11,223±382 K |
| Rotational velocity (v sin i) | 274 km/s |
| Age | 98 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
π2 Columbae, Latinized as Pi2 Columbae, is a binary star[9] system in the southern constellation of Columba, near the southern constellation border with Pictor. It is white-hued and dimly visible to the naked eye with a combined apparent visual magnitude of 5.50.[2] Based upon an annual parallax shift of 12.8 mas as seen from Earth,[1] this system is located about 254 light years from the Sun. They are receding with a heliocentric radial velocity of +31 km/s.[4]
The pair have an angular separation of 0.1[3] arc seconds with the primary being an A-type main-sequence star of spectral class A0 V,[3] while the secondary component is a similar A-type star.[9] The primary is 98 million years old with 2.6 times the mass of the Sun and is spinning rapidly with a projected rotational velocity of 274 km/s.[6] It is radiating 31[7] times the luminosity of the Sun from its photosphere at an effective temperature of 11,223 K. The system is a source of X-ray emission with a luminosity of 184.3×1020 W, which is considered unusual since A-type stars are not expected to display magnetic activity.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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.
- ↑ 2.0 2.1 2.2 Corben, P. M.; Stoy, R. H. (1968), "Photoelectric Magnitudes and Colours for Bright Southern Stars", Monthly Notes of the Astronomical Society of Southern Africa 27: 11, Bibcode: 1968MNSSA..27...11C.
- ↑ 3.0 3.1 3.2 3.3 Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics 475 (2): 677–684, doi:10.1051/0004-6361:20077429, Bibcode: 2007A&A...475..677S.
- ↑ 4.0 4.1 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G.
- ↑ 6.0 6.1 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D.
- ↑ 7.0 7.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ "pi02 Col". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=pi02+Col.
- ↑ 9.0 9.1 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
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