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] |
Distance | 96 ± 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] |
Distance | 97.9 ± 0.2 ly (30.00 ± 0.08 pc) |
Details | |
38 Gem A | |
Mass | 1.55[10] M☉ |
Surface gravity (log g) | 4.23[11] cgs |
Temperature | 7,410±252[11] K |
Metallicity [Fe/H] | −0.08±0.06[12] dex |
Rotational velocity (v sin i) | 147.5±10.5[13] km/s |
Age | 1.179[11] Gyr |
38 Gem B | |
Mass | 0.89[10] M☉ |
Radius | 0.89[9] R☉ |
Luminosity | 0.694[9] L☉ |
Temperature | 5,583[9] K |
Other designations | |
Database references | |
SIMBAD | data |
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]