38 Geminorum

This article is about e Geminorum. Not to be confused with ε (epsilon) Geminorum.
38 Geminorum
Observation data
Epoch J2000      Equinox J2000
Constellation Gemini
Right ascension 06h 54m 38.63478s[1]
Declination +13° 10′ 40.2207″[1]
Apparent magnitude (V) 4.75 + 7.80[2]
Characteristics
Spectral type A8V[3] + G6V[4]
U−B color index +0.07[5]
B−V color index +0.30[5]
Variable type Suspected δ Sct[6]
Astrometry
A
Radial velocity (Rv)+24±5[7] km/s
Proper motion (μ) RA: 68.745[8] mas/yr
Dec.: −86.832[8] mas/yr
Parallax (π)33.9184 ± 0.8248 mas[8]
Distance96 ± 2 ly
(29.5 ± 0.7 pc)
B
Radial velocity (Rv)+22.6±2[7] km/s
Proper motion (μ) RA: 89.235[9] mas/yr
Dec.: −77.171[9] mas/yr
Parallax (π)33.3308 ± 0.0847 mas[9]
Distance97.9 ± 0.2 ly
(30.00 ± 0.08 pc)
Details
38 Gem A
Mass1.55[10] M☉
Surface gravity (log g)4.23[11] cgs
Temperature7,410±252[11] K
Metallicity [Fe/H]−0.08±0.06[12] dex
Rotational velocity (v sin i)147.5±10.5[13] km/s
Age1.179[11] Gyr
38 Gem B
Mass0.89[10] M☉
Radius0.89[9] R☉
Luminosity0.694[9] L☉
Temperature5,583[9] K
Other designations
e Gem, 38 Gem, NSV 3266, BD+13°1462, GJ 9220, HD 50635, HIP 33202, HR 2564, SAO 96265, WDS J06546+1311
Database references
SIMBADdata
A
B

38 Geminorum is a binary star system in the northern zodiac constellation of Gemini. It has the Bayer designation e Geminorum, while 38 Geminorum is the Flamsteed designation. This system is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.71. The primary component is a magnitude 4.75 star, while the secondary is magnitude 7.80.[2] The system is located about 98 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +16 km/s.[14] It is a potential member of the Tucana–Horologium stellar kinematic group.[15]

This is a wide binary system with a projected separation of 184.3 AU.[10] Two sets of low quality orbital elements have been computed for this system, yielding periods of 1,943.8 years and 3,190 years, and eccentricities of 0.150 and 0.485, respectively.[16] As of 2018, the pair had an angular separation of 7.4″ along a position angle of 143°.[2]

Abt and Morrell (1995) classified the primary component as an A-type main-sequence star with a stellar classification of A8V.[3] It is a suspected chemically peculiar star of subtype CP1 (an Am star),[13] which Slettebak (1955) classified as kA8mF0Vp.[17] This notation indicates the star displays the calcium K line of an A8 star and the metal lines of an F0V star. In 1949, J. Hopmann catalogued it as a suspected Delta Scuti variable.[6] The secondary is a G-type main-sequence star with a class of G6V.[4]

  1. ^ a b Cite error: The named reference HIP was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Abt was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Adams1935 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Johnson was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Starikova1979 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference rv was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference dr2a was invoked but never defined (see the help page).
  9. ^ a b c d e f Cite error: The named reference dr2b was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference Tokovinin2016 was invoked but never defined (see the help page).
  11. ^ a b c Cite error: The named reference David2015 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference gaspar2016 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Paunzen2013 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference nakajima2012 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference apj629_1_507 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Slettebak1955 was invoked but never defined (see the help page).