G 9-38
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 58m 15.194s |
| Declination | +19° 45′ 47.08″ |
| Apparent magnitude (V) | 13.720 |
| Characteristics | |
| Spectral type | M8Ve+M7V |
| Astrometry | |
| G 9-38 A | |
| Radial velocity (Rv) | 13 ± 5 km/s |
| Proper motion (μ) | RA: −767.060±0.122 mas/yr Dec.: −100.176±0.083 mas/yr |
| Parallax (π) | 194.1443±0.1228 mas |
| Distance | 16.80 ± 0.01 ly (5.151 ± 0.003 pc) |
| G 9-38 B | |
| Proper motion (μ) | RA: −937.133±0.190 mas/yr Dec.: −34.559±0.138 mas/yr |
| Parallax (π) | 196.2619 ± 0.1976 mas |
| Distance | 16.62 ± 0.02 ly (5.095 ± 0.005 pc) |
| Orbit | |
| Primary | G 9-38A |
| Companion | G 9-38B |
| Period (P) | 360 yr |
| Semi-major axis (a) | 33 AU |
| Details | |
| G 9-38A | |
| Mass | 0.127±0.043 M☉ |
| Radius | 0.136±0.020 R☉ |
| Luminosity (bolometric) | 0.000965 L☉ |
| Temperature | 2896±18 K |
| Metallicity [Fe/H] | +0.08 dex |
| G 9-38B | |
| Mass | 0.111±0.045 M☉ |
| Radius | 0.119±0.021 R☉ |
| Luminosity (bolometric) | 0.000992 L☉ |
| Metallicity [Fe/H] | +0.14 dex |
| Other designations | |
| EI Cnc, GJ 1116, WDS J08582+1945AB, G 9-38, G 47-14, G 41-11, LP 426-40, LTT 12343, PLX 2144.03, GSC 01397-01138, 2MASS J08581519+1945470 | |
| A: Gaia DR2 660597997696173440, LHS 2076, NLTT 20638 | |
| B: Gaia DR2 660597997697274752, LHS 2077, NLTT 20637 | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
Location of G 9-38 in the constellation Cancer | |
G 9-38, also known as EI Cancri and GJ 1116, is a binary star system consisting of two M-type stars. Located at a distance of 16.7 light-years, it is among the nearest star systems.
In 1985, Bjørn Ragnvald Pettersen announced his discovery that the star shows very high stellar flare activity, with an average of five flares per hour. It was given its variable star designation, EI Cancri, in 1987.
In 2015, the search for third star in the system has yielded inconclusive results.