30 Geminorum

30 Geminorum
Observation data
Epoch J2000      Equinox J2000
Constellation Gemini
Right ascension 06h 43m 59.28697s[1]
Declination +13° 13′ 40.8188″[1]
Apparent magnitude (V) 4.49[2]
Characteristics
Spectral type K0+ III Ca1[3]
B−V color index 1.167±0.006[2]
Astrometry
Radial velocity (Rv)+9.50±0.25[4] km/s
Proper motion (μ) RA: −0.269[1] mas/yr
Dec.: −53.503[1] mas/yr
Parallax (π)10.9027 ± 0.2048 mas[1]
Distance299 ± 6 ly
(92 ± 2 pc)
Absolute magnitude (MV)−0.25[2]
Details
Mass2.29±0.62[5] M☉
Radius22.4+0.5
−0.8[1] R☉
Luminosity188.9±4.1[1] L☉
Surface gravity (log g)2.18±0.11[5] cgs
Temperature4,518+82
−47[1] K
Metallicity [Fe/H]−0.11±0.05[5] dex
Rotational velocity (v sin i)2.7[4] km/s
Age1.20+0.31
−0.25[5] Gyr
Other designations
30 Gem, BD+13°1390, HD 48433, HIP 32249, HR 2478, SAO 96051, WDS J06440+1314[6]
Database references
SIMBADdata

30 Geminorum is a suspected astrometric binary[7] star system in the northern zodiac constellation of Gemini. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.49.[2] The distance to this star, as estimated through the use of parallax, is about 299 light years.[1] It is drifting further away from the Sun with a heliocentric radial velocity of +9.5 km/s.[4]

This is an aging giant star with a stellar classification of K0+ III Ca1,[3] having exhausted the supply of hydrogen at its core and expanded to 22[1] times the Sun's radius. The suffix notation indicates it displays an overabundance of calcium in its spectrum. It is a red clump giant,[8] which means it is on the horizontal branch and is generating energy through helium fusion at its core. The star is about 1.2[5] billion years old with 2.3[5] times the Sun's mass. It is radiating 189[1] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,518 K.[1]

There is a 13th magnitude visual companion located at an angular separation of 21.20″ along a position angle of 187° from the brighter star, as of 2011.[9]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference keenan1989 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  5. ^ a b c d e f Cite error: The named reference Feuillet2016 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Alves2000 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).