Gliese 357

Red dwarf with low starspot activity in the Hydra constellation

Gliese 357
Observation data Epoch J2000 Equinox J2000
Artist concept of the Gliese 357 (GJ357) system. Credit: Jack Madden
Constellation	Hydra
Right ascension	09^h 36^m 01.63722^s^[1]
Declination	−21° 39′ 38.8776″^[1]
Apparent magnitude (V)	10.906^[2]
Characteristics
Evolutionary stage	main sequence
Spectral type	M2.5V^[3]
Astrometry

Radial velocity (R_v)	−35.03±0.17^[1] km/s
Proper motion (μ)	RA: 138.722±0.023 mas/yr^[1] Dec.: −990.342±0.020 mas/yr^[1]
Parallax (π)	105.9789 ± 0.0227 mas^[1]
Distance	30.776 ± 0.007 ly (9.436 ± 0.002 pc)
Absolute magnitude (M_V)	+11.13^[4]

Details

Mass	0.362^[5] `M`_☉
Radius	0.333^[4] `R`_☉
Luminosity	0.014^[6] `L`_☉
Surface gravity (log g)	4.96^[5] cgs
Temperature	3,488^[5] K
Metallicity [Fe/H]	−0.14^[5] dex
Rotation	74.3±1.7 d^[7]
Rotational velocity (v sin i)	2.5^[5] km/s

Other designations
HIP 47103, 2MASS 09360161-2139371, TOI 562
Database references
SIMBAD	data

GJ 357 (also designated Gliese 357) is an M-type main sequence star with an unusually low starspot activity.^[8] It is located 31 light-years from the Solar System.^[9] The system is part of the Hydra constellation.^[9]

Planetary system

The star has three confirmed exoplanets in its orbit,^[10] one of which, Gliese 357 d, is considered to be a "super-Earth" within the circumstellar habitable zone.^[11]^[9]^[12]^[13]

Planets b and c are close to 3:7 mean-motion resonance. Presuming resonance chain crosses gap to outermost and cold super-terrestrial d and the resonances are simple, GJ 357 may have much more suitable planet for life at approx. 27.5 day period and almost Earth's flux, and (less likely) Mars-sized planet in 2:1 period ratio with GJ 357 c and 2:3 ratio with hypothetical HZ rocky one.^{[citation needed]}

The Gliese 357 planetary system^[14]
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	—	—

References

^ ^a ^b ^c ^d ^e 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.
^ Koen, C.; Kilkenny, D.; Van Wyk, F.; Marang, F. (2010). "UBV(RI)_C JHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society. 403 (4): 1949. Bibcode:2010MNRAS.403.1949K. doi:10.1111/j.1365-2966.2009.16182.x.
^ Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
^ ^a ^b Houdebine, E. R.; Mullan, D. J.; Paletou, F.; Gebran, M.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2016). "Rotation-Activity Correlations in K and M Dwarfs. I. Stellar Parameters and Compilations of v sin I and P/Sin I for a Large Sample of Late-K and M Dwarfs". The Astrophysical Journal. 822 (2): 97. arXiv:1604.07920. Bibcode:2016ApJ...822...97H. doi:10.3847/0004-637X/822/2/97. S2CID 119118088.
^ ^a ^b ^c ^d ^e Passegger, V. M.; Reiners, Ansgar; Jeffers, S. V.; Wende-von Berg, S.; Schöfer, P.; Caballero, J. A.; Schweitzer, A.; Amado, P. J.; Béjar, V. J. S.; Cortés-Contreras, M.; Hatzes, A. P.; Kürster, M.; Montes, D.; Pedraz, S.; Quirrenbach, A.; Ribas, I.; Seifert, W. (2018). "The CARMENES search for exoplanets around M dwarfs. Photospheric parameters of target stars from high-resolution spectroscopy". Astronomy and Astrophysics. 615: A6. arXiv:1802.02946. Bibcode:2018A&A...615A...6P. doi:10.1051/0004-6361/201732312. S2CID 55639432.
^ Morales, J. C.; Ribas, I.; Jordi, C.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2008). "The effect of activity on stellar temperatures and radii". Astronomy and Astrophysics. 478 (2): 507. arXiv:0711.3523. Bibcode:2008A&A...478..507M. doi:10.1051/0004-6361:20078324. S2CID 16238033.
^ Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.; Esposito, M. (2015), "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators", Monthly Notices of the Royal Astronomical Society, 452 (3): 2745–2756, arXiv:1506.08039, Bibcode:2015MNRAS.452.2745S, doi:10.1093/mnras/stv1441
^ Modirrousta-Galian, D.; Stelzer, B.; Magaudda, E.; Maldonado, J.; Güdel, M.; Sanz-Forcada, J.; Edwards, B.; Micela, G. (2020), "A Super-Earth Orbiting an Extremely Inactive Host Star", Astronomy & Astrophysics, A113: 641, arXiv:2007.10262, doi:10.1051/0004-6361/202038280, S2CID 220647396
^ ^a ^b ^c Reddy, Francis; Center, NASA’s Goddard Space Flight (2019-07-31). "TESS Discovers Habitable Zone Planet in GJ 357 System". SciTechDaily. Retrieved 2019-08-01.
^ "The Extrasolar Planet Encyclopaedia — Gj 357 b". Extrasolar Planets Encyclopaedia. 1995. Retrieved 2019-08-01.
^ Falconer, Rebecca, Newly uncovered super-Earth 31 light-years away may be habitable, Axios, August 1, 2019
^ "Potentially habitable 'super-Earth' discovered just 31 light-years away". NBC News. 31 July 2019. Retrieved 2019-08-01.
^ Garner, Rob (2019-07-30). "NASA's TESS Helps Find Intriguing New World". NASA. Retrieved 2019-08-01.
^ Luque, R.; Pallé, E.; et al. (August 2019). "Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization". Astronomy & Astrophysics. 628: A39. arXiv:1904.12818. Bibcode:2019A&A...628A..39L. doi:10.1051/0004-6361/201935801. S2CID 139102184.

Constellation of Hydra

Stars

Bayer	α (Alphard) β γ δ ε (Ashlesha) ζ η θ ι (Ukdah) κ λ μ ν ξ ο π ρ σ (Minchir) τ¹ τ² υ¹ (Zhang) υ² φ¹ φ² φ³ χ¹ χ² ψ ω
Flamsteed	1 2 3 6 (a) 9 10 12 (D) 14 15 17 19 20 21 23 24 25 26 27 (P) 28 29 33 (A) 34 37 44 47 48 50 51 (k) 52 (l) 54 (m) 55 56 57 58 (E) 59 60 3 Crt (b¹) 5 Crt (b²) 6 Crt (b³) 10 Crt 17 Crt (N) 20 Crt 14 Lib 30 Mon (C) 31 Mon (F) 2 Sex
Variable	R U V W TW EX HS KU LQ V419 V421 V478
HR	3378 3538 3749 (G) 3750 3858 (I) 3862 3919 3923 (Felis) 4162 4328 4339 4445 5265
HD	72659 74156 82943 86226 86264 90156
Gliese	328 357 433 453 3517 3634
Other	HE 1256-2738 HE 1327-2326 LHS 2065 LHS 3003 LTT 3780 2MASS 1114−2618 WASP-25 WASP-36 WASP-84 WISE 0855−0714 SSSPM J0829-1309

Star clusters

Open	Messier 48
Globular	Messier 68 NGC 5694

Nebulae

Planetary	Abell 33 NGC 3242

Galaxies

Messier	83
NGC	2617 2835 2865 2936 2992 3054 3081 3109 3285 3305 3307 3308 3309 3311 3312 3313 3314 3315 3316 3336 3369 3393 3402 3464 3585 3621 3717 3923 4980 4993 5078 5101 5135 5264
Other	AM 1316-241 Arp 7 ESO 510-G13 GAMA202627 LEDA 1026855 MCG -01-24-014 MRC 1138-262 Peekaboo Galaxy TN J0924-2201 Tololo 1247-232