Kappa Geminorum

κ Geminorum
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Gemini
Right ascension 07h 44m 26.85357s[1]
Declination +24° 23′ 52.7872″[1]
Apparent magnitude (V) 3.568[2] + 8.2[3]
Characteristics
Spectral type G9 III[4]
U−B color index +0.700[2]
B−V color index +0.941[2]
Astrometry
Radial velocity (Rv)20.6[5] km/s
Proper motion (μ) RA: −23.39[1] mas/yr
Dec.: −54.57[1] mas/yr
Parallax (π)23.07 ± 0.22 mas[1]
Distance141 ± 1 ly
(43.3 ± 0.4 pc)
Absolute magnitude (MV)+0.35[6]
Details
Mass2.07[7] M☉
Radius11.00±0.16[8] R☉
Luminosity69.3±3.7[8] L☉
Surface gravity (log g)2.8[9] cgs
Temperature5,020±68[8] K
Metallicity [Fe/H]−0.16[9] dex
Rotational velocity (v sin i)3.3[9] km/s
Age2.07[7] Gyr
Other designations
κ Gem, 77 Geminorum, BD+24° 1759, FK5 294, HD 62345, HIP 37740, HR 2985, SAO 79653.[10]
Database references
SIMBADdata

Kappa Geminorum (κ Geminorum, κ Gem) is a binary star system in the northern zodiac constellation of Gemini. It is visible to the naked eye with an apparent visual magnitude of 3.568.[2] Based upon an annual parallax shift of 23.07 mas,[1] the system is located about 141 light years distant from the Sun.

In Chinese astronomy, Kappa Geminorum is called 積薪, Pinyin: Jīxīn, meaning Pile of Firewood, because this star is marking itself and stand alone in Pile of Firewood asterism, Well mansion (see : Chinese constellation).[11] 積薪 (Jīxīn) westernized into Tseih Tsing, but the name Tseih Tsing was designated for χ Gem and μ Cnc by R.H. Allen, with the meaning is "piled-up fuel"[12] In Japanese, 隆博星 (Takahiro-boshi), meaning "Esteemed Nobility Star," refers to the Japanese description of κ Geminorum.

This is a probable astrometric binary[3] system with the components having an angular separation of 7.2 arcseconds along a position angle of 241°, as of 2014.[13] The primary is an evolved G-type giant star with a stellar classification of G9 III.[4] Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[14] It has double the mass of the Sun,[7] but has expanded to 11 times the solar radius. The star radiates around 69 times the Sun's luminosity from its outer atmosphere at an effective temperature of 5,020 K.[8] It shows a leisurely spin with a projected rotational velocity of 3.3 km/s, and is around two billion years old.[7] The secondary component is a magnitude 8.2 star.[3]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Jennens1975 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Abt2008 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gcrv1953 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Cardini2005 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference luck2015 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference baines2018 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 16 日
  12. ^ Cite error: The named reference Allen was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference baas25_1319 was invoked but never defined (see the help page).