Gliese 12 (GJ 12) is a red dwarf star located 39.7 light-years (12.2 parsecs) away in the constellation Pisces. It has about 24% the mass and 26% the radius of the Sun, and a temperature of about 3,296 K (3,023 °C; 5,473 °F). It is an inactive star and hosts one known exoplanet.[5]
 Artist's impression of Gliese 12 and its planet (foreground) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pisces[1] |
| Right ascension | 00h 15m 49.24231s[2] |
| Declination | +13° 33′ 22.3163″[2] |
| Apparent magnitude (V) | 12.6[3] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | M4V[4] |
| Apparent magnitude (V) | 12.600±0.04[3] |
| Apparent magnitude (R) | 12.296±0.08[3] |
| Apparent magnitude (G) | 11.399±0.003[2] |
| Apparent magnitude (J) | 8.619±0.020[3] |
| Apparent magnitude (H) | 8.068±0.026[3] |
| Apparent magnitude (K) | 7.807±0.020[3] |
| Astrometry | |
| Radial velocity (Rv) | 51.04±0.26[2] km/s |
| Proper motion (μ) | RA: 618.065 mas/yr[2] Dec.: 329.446 mas/yr[2] |
| Parallax (π) | 82.1938 ± 0.0326 mas[2] |
| Distance | 39.68 ± 0.02 ly (12.166 ± 0.005 pc) |
| Details[5] | |
| Mass | 0.2414±0.0060 M☉ |
| Radius | 0.2617+0.0058 −0.0070 R☉ |
| Luminosity (bolometric) | 0.00728±0.00015 L☉ |
| Surface gravity (log g) | 5.21±0.07 cgs |
| Temperature | 3,296+48 −36 K |
| Metallicity [Fe/H] | −0.32±0.06 dex |
| Rotation | 85 days |
| Rotational velocity (v sin i) | <2 km/s |
| Age | 7.0+2.8 −2.2[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Planetary system
editThe transiting exoplanet Gliese 12 b was discovered by TESS, and two independent studies confirming it as a planet were published in May 2024.[5][6] Gliese 12 b is similar in size to Earth and Venus, and completes an orbit around its star every 12.8 days. Its mass is poorly constrained but is known to be less than 4 times that of Earth.[5]
Along with the planets of TRAPPIST-1 and LHS 1140 b, Gliese 12 b is one of the nearest known relatively temperate transiting exoplanets, and so is a promising target for the James Webb Space Telescope to determine whether it has retained an atmosphere.[7] Gliese 12 b orbits slightly closer than the inner edge of its star's habitable zone, with an insolation between those of Earth and Venus.[6] Its equilibrium temperature, assuming an albedo of zero, is 315 K (42 °C; 107 °F); if it has an atmosphere, the surface temperature would be greater than this.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | <3.87 M🜨 | 0.0668±0.0024 | 12.761408±0.000050 | <0.50 | 89.194+0.059 −0.052° |
0.958+0.046 −0.048 R🜨 |
References
edit- ^ "Finding the constellation which contains given sky coordinates". djm.cc. 2 August 2008. Archived from the original on 15 August 2019. Retrieved 23 May 2024.
- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g "GJ 12". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 May 2024.
- ^ Newton, Elisabeth R.; Charbonneau, David; et al. (January 2014). "Near-infrared Metallicities, Radial Velocities, and Spectral Types for 447 Nearby M Dwarfs". The Astronomical Journal. 147 (1): 20. arXiv:1310.1087. Bibcode:2014AJ....147...20N. doi:10.1088/0004-6256/147/1/20.
- ^ a b c d e f Kuzuhara, Masayuki; Fukui, Akihiko; et al. (23 May 2024). "Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy". The Astrophysical Journal Letters. 967 (2): L21. arXiv:2405.14708. Bibcode:2024ApJ...967L..21K. doi:10.3847/2041-8213/ad3642.
- ^ a b c Dholakia, Shishir; Palethorpe, Larissa; et al. (23 May 2024). "Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TESS and CHEOPS". Monthly Notices of the Royal Astronomical Society. 531 (1): 1276–1293. arXiv:2405.13118. Bibcode:2024MNRAS.531.1276D. doi:10.1093/mnras/stae1152.
- ^ Reddy, Francis (23 May 2024). "NASA's TESS Finds Intriguing World Sized Between Earth, Venus". NASA. Archived from the original on 23 May 2024. Retrieved 23 May 2024.