Nu2 Canis Majoris

ν2 Canis Majoris
Location of ν2 Canis Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canis Major
Right ascension 06h 36m 41.03758s[1]
Declination −19° 15′ 21.1659″[1]
Apparent magnitude (V) 3.96[2]
Characteristics
Spectral type K1 III[2]
Astrometry
Radial velocity (Rv)+2.57±0.14[3] km/s
Proper motion (μ) RA: +62.57±0.15[1] mas/yr
Dec.: −69.97±0.16[1] mas/yr
Parallax (π)50.63 ± 0.23[1] mas
Distance64.4 ± 0.3 ly
(19.75 ± 0.09 pc)
Absolute magnitude (MV)−0.05[2]
Details[4]
Mass1.3±0.1 M☉
Radius4.9±0.1 R☉
Luminosity11.3±0.1 L☉
Surface gravity (log g)3.18±0.03 cgs
Temperature4,790±27 K
Metallicity [Fe/H]0.21±0.10 dex
Rotational velocity (v sin i)1.97±0.23[3] km/s
Age4.6±0.7 Gyr
Other designations
ν2 CMa, 7 CMa, BD−19° 1502, FK5 2510, GC 8624, GJ 239.1, HD 47205, HIP 31592, HR 2429, SAO 151702
Database references
SIMBADdata

Nu2 Canis Majoris (ν2 Canis Majoris) is a single[5] star in the southern constellation of Canis Major. With an apparent visual magnitude of 3.96,[2] it is bright enough to be seen with the naked eye to the southeast of Sirius. Based upon an annual parallax shift of 50.63 mas as seen from Earth,[1] this system is located 64.4 light years from the Sun. It is an evolved K-type giant around 4.6 billion years old. Around 1.3 times as massive as the Sun, it has expanded to around 4.9 times the Sun's diameter and 11 times its luminosity.[4] In 2011, it was found to have a planet.[6]

Chinese name

In Chinese astronomy, ν2 Canis Majoris is called 野雞, Pinyin: Yějī, meaning Wild Cockerel, because this star is marking itself and stand alone in Wild Cockerel asterism, Well mansion (see : Chinese constellation).[7] 野雞 (Yějī), westernized into Ya Ke. According to R.H. Allen opinion, the name Ya Ke is asterism consisting ο1 Canis Majoris and π Canis Majoris, with other small stars in the body of the Dog[8]

Planetary system

By measuring periodic variations in the radial velocity of the host star between 2009 and 2010, the Pan-Pacific Planet Search program was able to identify a planet orbiting Nu2 Canis Majoris. An orbital fit produced a minimum mass estimate of 2.6±0.6 MJwith an orbital period of 2.1 years and an eccentricity of 0.23. Star spots were ruled out as a source for the signal with a false-alarm probability of 98.7%.[6]

The Nu2 Canis Majoris planetary system[6]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥2.6 ± 0.6 MJ 1.9 ± 0.1 763 ± 17 0.14 ± 0.06 — —

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. 1 2 3 4 Setiawan, J.; et al. (July 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, 421: 241–254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1.
  3. 1 2 Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474.
  4. 1 2 Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
  5. ↑ 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.
  6. 1 2 3 Wittenmyer; et al. (2011). "The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa". The Astrophysical Journal. 743 (2): 184. arXiv:1111.1007. Bibcode:2011ApJ...743..184W. doi:10.1088/0004-637X/743/2/184.
  7. ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日
  8. ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Canis Major
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.