Astronomy:Gamma Canis Minoris

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Short description: Binary star system in the constellation Canis Minor
γ Canis Minoris
Location of γ Canis Minoris (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Canis Minor
Right ascension  07h 28m 09.794s[1]
Declination +08° 55′ 31.89″[1]
Apparent magnitude (V) +4.33[2] (4.46 + 6.66)[2]
Characteristics
Spectral type K3 III Fe-0.5[3] (K4 III + K1: III)[2]
U−B color index +1.53[4]
B−V color index +1.43[4]
Astrometry
Radial velocity (Rv)46.8±0.3[5] km/s
Proper motion (μ) RA: −62.112[1] mas/yr
Dec.: −11.141[1] mas/yr
Parallax (π)3.134 ± 0.1714[1] mas
Distance1,040 ± 60 ly
(320 ± 20 pc)
Absolute magnitude (MV)−0.5±0.1[2]
Absolute magnitude (MV)1.7±0.2[2]
Orbit[2]
Period (P)389.310±0.012d
Semi-major axis (a)17 mas
Eccentricity (e)0.25856±0.00039
Inclination (i)66°
Periastron epoch (T)2449849.172±0.089 HJD
Argument of periastron (ω)
(secondary)
142.079±0.090°
Semi-amplitude (K1)
(primary)
21.243±0.010 km/s
Semi-amplitude (K2)
(secondary)
21.526±0.017 km/s
Details[2]
γ CMi A
Mass1.88 M☉
Radius36.8±2.6 R☉
Luminosity321±33 L☉
Temperature4,036±100 K
Rotational velocity (v sin i)5±2 km/s
Age1.3 Gyr
γ CMi B
Mass1.85 M☉
Radius7.8±1.0 R☉
Luminosity25.4±5.2 L☉
Temperature4,658±200 K
Rotational velocity (v sin i)2.0±2.0 km/s
Other designations
γ CMi, 4 CMi, BD+09°1660, GC 9974, HD 58972, HIP 36284, HR 2854, SAO 115478, ADS 6100, CCDM 07281+0856, WDS J07282+0856A[6]
Database references
SIMBADdata

Gamma Canis Minoris is a binary star system in the equatorial constellation Canis Minor. Its name is a Bayer designation that is Latinized from γ Canis Minoris, and abbreviated Gamma CMi or γ CMi. The orange colour is obvious when seen through binoculars.[7] The system is visible to the naked eye with a combined apparent visual magnitude of +4.33.[2] Based upon an annual parallax shift of 3.13 mas as seen from Earth,[1] this system is located at a distance of approximately 1,040 light-years (320 pc) from the Sun. It is drifting further away with a line of sight velocity of 47 km/s.[5]

This spectroscopic binary star system has an orbital period of 389.31 days, a semimajor axis of 1.48 AU, and an eccentricity of 0.2586.[2] Their variable radial velocity was discovered by H. M. Reese in 1902 at Lick Observatory.[8] Both components are evolved, K-type giant stars, most likely on their first ascent along the red giant branch. The primary, component A, has a stellar classification of K4 III while the secondary, component B, may be K1: III.[2]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940.  Gaia DR3 record for this source at VizieR.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Fekel, F. C. et al. (March 2013), "The spectroscopic orbit of the K-giant binary γ Canis Minoris", Astronomische Nachrichten 334 (3): 223, doi:10.1002/asna.201211842, Bibcode: 2013AN....334..223F. 
  3. ↑ Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode: 1989ApJS...71..245K. 
  4. ↑ 4.0 4.1 Johnson, H. L. (1966), "UBVRIJKL Photometry of the Bright Stars", Communications of the Lunar and Planetary Laboratory 4: 99, Bibcode: 1966CoLPL...4...99J. 
  5. ↑ 5.0 5.1 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. 
  6. ↑ "gam CMi". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=gam+CMi. 
  7. ↑ Kambič, Bojan (2009), Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore, Springer, p. 32, ISBN 978-0387853543, https://books.google.com/books?id=3vxLNPNHOcwC&pg=PA233. 
  8. ↑ Campbell, W. W. (September 1902), "Six stars whose velocities in the line of sight are variable", Astrophysical Journal 16: 114–117, doi:10.1086/140954, Bibcode: 1902ApJ....16..114C.