GJ 1252
Red dwarf star in the constellation Telescopium
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GJ 1252 is a red dwarf star located 66.5 light-years (20.4 parsecs) away from the Solar System in the constellation of Telescopium. The star has about 38% the mass and 39% the radius of the Sun, and a temperature of about 3,458 K (3,185 °C; 5,765 °F). GJ 1252 is orbited by one known exoplanet.[3]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Telescopium[1] |
| Right ascension | 20h 27m 42.08140s[2] |
| Declination | −56° 27′ 25.1519″[2] |
| Apparent magnitude (V) | 12.193[3] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | M2.5V[4] |
| Apparent magnitude (B) | 13.655±0.029[3] |
| Apparent magnitude (V) | 12.193±0.056[3] |
| Apparent magnitude (G) | 11.235±0.003[2] |
| Apparent magnitude (J) | 8.697±0.019[3] |
| Apparent magnitude (H) | 8.161±0.034[3] |
| Apparent magnitude (K) | 7.915±0.023[3] |
| Astrometry | |
| Radial velocity (Rv) | 7.38±0.29[2] km/s |
| Proper motion (μ) | RA: 424.417 mas/yr[2] Dec.: −1,230.941 mas/yr[2] |
| Parallax (π) | 49.0555±0.0247 mas[2] |
| Distance | 66.49 ± 0.03 ly (20.39 ± 0.01 pc) |
| Details | |
| Mass | 0.381±0.008[5] M☉ |
| Radius | 0.391±0.012[5] R☉ |
| Luminosity (bolometric) | 0.0196+0.0026 −0.0023[3] L☉ |
| Surface gravity (log g) | 4.83±0.03[5] cgs |
| Temperature | 3,458+140 −133[3] K |
| Metallicity [Fe/H] | −0.18±0.13[5] dex |
| Age | 3.9±0.4[6] Gyr |
| Other designations | |
| GJ 1252, L 210-70, LFT 1546, LHS 492, LTT 8083, NLTT 49258, PM J20277-5627, TOI-1078, TIC 370133522, GCRV 26183, 2MASS J20274210-5627262[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
Planetary system
GJ 1252 was found to have a planet, GJ 1252 b, in 2019 using transit observations from TESS.[3] It is a terrestrial planet larger than Earth, with about 1.3 times the mass and 1.18 times the radius of Earth. Orbiting its star with a very short period of just 12.4 hours, it is presumably tidally locked. Secondary eclipse observations have shown that GJ 1252 b lacks a significant atmosphere, similar to LHS 3844 b and TRAPPIST-1b, and have measured its dayside temperature at about 1,410 K (1,140 °C; 2,080 °F).[6][8]
A candidate second planet was identified in 2022 with Doppler spectroscopy (radial velocity method), named GJ 1252 c.[9] It orbits with a period of 18.41 days and has a mass of at least 6.08 M🜨. The existence of this planet in uncertain, as the radial velocity variations may be intrinsic to the star rather than due to the gravitational pull of an orbiting body.[5]