GJ 1128
Star in the southern constellation of Carina
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GJ 1128 is a star in the constellation Carina. It is somewhat nearby, located about 21.212 light-years away from Earth.
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Carina[1] |
| Right ascension | 09h 42m 46.3430s[2] |
| Declination | −68° 53′ 06.009″[2] |
| Apparent magnitude (V) | 12.78[3] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | M4.0V[4] |
| Astrometry | |
| Proper motion (μ) | RA: −75.828[2] mas/yr Dec.: +1128.849[2] mas/yr |
| Parallax (π) | 153.7593±0.0249 mas[2] |
| Distance | 21.212 ± 0.003 ly (6.504 ± 0.001 pc) |
| Absolute magnitude (MV) | 13.715[3] |
| Details | |
| Mass | 0.175[5] M☉ |
| Radius | 0.190[3] R☉ |
| Luminosity | 0.0043[6] L☉ |
| Surface gravity (log g) | 5.03[6] cgs |
| Temperature | 3,144[3] K |
| Metallicity [Fe/H] | 0.09[3] dex |
| Rotation | 157.4 days[7] |
| Other designations | |
| GJ 1128[8], L 100-115, LFT 680, LHS 271[9], LTT 3572, NLTT 22480[10], GSC 09209-00444, 2MASS J09424635-6853060, DENIS J094246.3-685309 | |
| Database references | |
| SIMBAD | data |
GJ 1128 is a red dwarf star with a mere 0.43% of the solar luminosity,[6] and an estimated mass 17.5% of the mass of the Sun.[5] It has 19% of the solar radius and its effective temperature is around 3,100 K, values comparable to the Barnard's Star.[3] It is a long-term variable with the prominent 5-year starspot cycle comparable to that of Sun's.[11]
The discovery designation of GJ 1128 is L 100-115,[12] from a 1944 catalogue of high-proper-motion stars.[13] It was then included in the 1979 Gliese–Jahreiss catalogue of nearby stars with an estimated parallax of 125 mas.[14] The small distance from Sun to the GJ 1128 was confirmed by later direct measurements of its parallax.[11]