Gliese 357
Red dwarf with low starspot activity in the Hydra constellation
From Wikipedia, the free encyclopedia
GJ 357 (Gliese 357) is an M-type main sequence star with an unusually low star spot activity.[9] It is located 31 light-years from the Solar System,[10] in the Hydra constellation.[10]
Artist concept of the Gliese 357 (GJ357) system. Credit: Jack Madden | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydra[1] |
| Right ascension | 09h 36m 01.63722s[2] |
| Declination | −21° 39′ 38.8776″[2] |
| Apparent magnitude (V) | 10.906[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | M2.5V[5] |
| Astrometry | |
| Radial velocity (Rv) | −35.03±0.17[2] km/s |
| Proper motion (μ) | RA: 138.722(23) mas/yr[2] Dec.: −990.342(20) mas/yr[2] |
| Parallax (π) | 105.9789±0.0227 mas[2] |
| Distance | 30.776 ± 0.007 ly (9.436 ± 0.002 pc) |
| Absolute magnitude (MV) | +11.13[6] |
| Details | |
| Mass | 0.362[4] M☉ |
| Radius | 0.333[6] R☉ |
| Luminosity | 0.014[7] L☉ |
| Surface gravity (log g) | 4.96[4] cgs |
| Temperature | 3,488[4] K |
| Metallicity [Fe/H] | −0.14[4] dex |
| Rotation | 74.3±1.7 d[8] |
| Rotational velocity (v sin i) | 2.5[4] km/s |
| Other designations | |
| HIP 47103, TOI-562, 2MASS 09360161-2139371 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
Planetary system
The star has three confirmed exoplanets in its orbit. [11] One of these, Gliese 357 d, is considered to be a "super-Earth" within the circumstellar habitable zone.[12][10][13][14]
Transmission spectroscopy of the planet b with JWST in 2025 found no clear evidence for atmospheric molecules, although a secondary atmosphere is considered likely to exist.[15] Similarly, another 2025 analysis of the JWST transmission spectrum found no atmospheric molecules, but was able to rule out an atmosphere composed mainly of low-molar mass molecules (less than 8 g/mol) and an abundance of metals less than 300 times that of the Sun.[16]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.84±0.31 M🜨 | 0.035±0.002 | 3.93072+0.00008 −0.00006 |
0.047+0.059 −0.047 |
89.12+0.37 −0.31° |
1.217+0.084 −0.083 R🜨 |
| c | ≥3.40±0.46 M🜨 | 0.061±0.004 | 9.1247+0.0011 −0.0010 |
0.072±0.053 | — | — |
| d | ≥6.1±1.0 M🜨 | 0.204±0.015 | 55.661±0.055 | 0.033+0.057 −0.033 |
— | — |