| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 16m 36.83456s[1] |
| Declination | −23° 18′ 56.1383″[1] |
| Apparent magnitude (V) | 4.79[2] |
| Characteristics | |
| Spectral type | K3Ib-[3] or K4III[4] |
| B−V color index | 1.710[2] |
| Astrometry | |
| Radial velocity (Rv) | +28.05±0.42[5] km/s |
| Proper motion (μ) | RA: −3.816[1] mas/yr Dec.: +3.896[1] mas/yr |
| Parallax (π) | 1.2155 ± 0.0998 mas[1] |
| Distance | 2,700 ± 200 ly (820 ± 70 pc) |
| Details | |
| Mass | 1.90[2] or 7.8±0.5[6] M☉ |
| Radius | 241[5] R☉ |
| Luminosity | 5,248[2] L☉ |
| Surface gravity (log g) | 0.70[2] cgs |
| Temperature | 3,937±141[2] K |
| Metallicity [Fe/H] | 0.03[2] dex |
| Rotational velocity (v sin i) | 7.4±1.0[7] km/s |
| Age | 1.05 Gyr[2] or 35.4±2.0[6] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
145 G. Canis Majoris (HD 56577) is a single[9] K giant or supergiant star in the southern constellation of Canis Major.This star is Gould's 145th of Canis Major in his Uranometria Argentina. [10] Kostjuk erroneously lists it as simply "145 CMa". SIMBAD follows this error in its object query result as "* 145 CMa – Star".[11]
The properties and evolutionary state of 145 G. CMa are disputed, it being classed either as a young massive supergiant or a somewhat older and less massive giant.[2][6] At the distance implied by its parallax, it would have a luminosity of 14,000 L☉, rather high for a giant.[5] Other studies based on older Hipparcos parallax measurements with a closer distance derive a luminosity more typical of low-mass giant stars.[2]
The star is one component of a close double, the other being HD 56578 which on its own would be a faint naked-eye star. The two are separated by 27″.[12] The two stars appear to be unrelated and the close alignment accidental, with HD 56578 being a much closer and less luminous Am star.[13]
References[edit]
- ^ a b c d e 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.
- ^ a b c d e f g h i j Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88, S2CID 118505114.
- ^ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
- ^ Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c Tetzlaff, N.; et al. (January 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.
- ^ De Medeiros, J. R.; et al. (2002), "A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars", Astronomy and Astrophysics, 395: 97–98, arXiv:1312.3474, Bibcode:2002A&A...395...97D, doi:10.1051/0004-6361:20021214.
- ^ "HD 56577". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-01-06.
- ^ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Gould, B. A., (2009) Uranometria Argentina, (Reprinted and updated by Pilcher, F.)[1] Archived 2016-03-05 at the Wayback Machine
- ^ SIMBAD query * 145 CMa – Star
- ^ 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.
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
