Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydra |
Right ascension | 09h 36m 01.63722s [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 (Rv) | −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 (MV) | +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 | |
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]
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 ]
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 | — | — |
GJ 1061 is a red dwarf star located 12 light-years from Earth in the southern constellation of Horologium. Even though it is a relatively nearby star, it has an apparent visual magnitude of about 13, so it can only be seen with at least a moderately-sized telescope.
Luyten's Star (GJ 273) is a red dwarf in the constellation Canis Minor located at a distance of 12.35 light-years from the Sun. It has a visual magnitude of 9.9, making it too faint to be viewed with the unaided eye. It is named after Willem Jacob Luyten, who, in collaboration with Edwin G. Ebbighausen, first determined its high proper motion in 1935. The star has two confirmed planets and two candidate planets, of which Luyten b is in the circumstellar habitable zone.
HD 101930, also known as Gliese 3683, is an orange hued star with an orbiting exoplanet located in the southern constellation Centaurus. It has an apparent magnitude of 8.21, making it faintly visible in binoculars but not to the naked eye. The system is located relatively close at a distance of 98 light years but is receding with a heliocentric radial velocity of 18.4 km/s. It has a relatively large proper motion, traversing the celestial sphere with an angular velocity of 0.320″·yr−1.
HD 28185 is a yellow dwarf star similar to the Sun located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess one long-period extrasolar planet.
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Gliese 682 or GJ 682 is a red dwarf. It is listed as the 53rd-nearest known star system to the Sun, being 16.3 light years away from the Earth. Even though it is close by, it is dim with a magnitude of 10.95 and thus requires a telescope to be seen. It is located in the constellation of Scorpius, near the bright star Theta Scorpii. The star is in a crowded region of sky near the Galactic Center, and so appears to be near a number of deep-sky objects from the Solar System's perspective. The star is only 0.5 degrees from the much more distant globular cluster NGC 6388.
BD−17 63 is a low-mass K-type main-sequence star in the southern constellation Cetus. It is a 10th magnitude star at a distance of 113 light-years from Earth. The star is rotating slowly with a negligible level of magnetic activity and an age of over 4 billion years.
Gliese 163 is a faint red dwarf star with multiple exoplanetary companions in the southern constellation of Dorado. Other stellar catalog names for it include HIP 19394 and LHS 188. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 11.79 and an absolute magnitude of 10.91. This system is located at a distance of 49.4 light-years from the Sun based on parallax measurements. Judging by its space velocity components, it is most likely a thick disk star.
Gliese 221, also known as BD-06 1339, is a star with an exoplanetary companion in the equatorial constellation of Orion. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 9.70 and an absolute magnitude of 8.15. Using parallax measurements, the distance to this system can be estimated as 66.2 light-years. It is receding from the Sun with a radial velocity of +23 km/s. This is a high proper motion star, traversing the celestial sphere at an angular rate of 0.333″·yr−1.
Gliese 754 is a dim star in the southern constellation of Telescopium. It has an apparent visual magnitude of 12.25, which requires a telescope to view. The star is located at a distance of 19.3 light-years from the Sun based on parallax, and it is drifting further away with a radial velocity of +7 km/s. It is one of the hundred closest stars to the Solar System. Calculations of its orbit around the Milky Way showed that it is eccentric, and indicate that it might be a thick disk object.
Gliese 180, is a small red dwarf star in the equatorial constellation of Eridanus. It is invisible to the naked eye with an apparent visual magnitude of 10.9. The star is located at a distance of 39 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −14.6 km/s. It has a high proper motion, traversing the sky at the rate of 0.765 arcseconds per year.
GJ 625 is a small red dwarf star with an exoplanetary companion in the northern constellation of Draco. The system is located at a distance of 21.1 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −13 km/s. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 10.13 and an absolute magnitude of 11.06.
Gliese 686 is a star in the constellation of Hercules, with an apparent magnitude +9.577. Although it is close to the Solar System – at 26.6 light-years – it is not the closest known star in its constellation, since Gliese 661 is 20.9 light years away. The closest system to this star is the bright μ Herculis, at 4.5 light years. They are followed by GJ 1230 and Gliese 673, at 7.2 and 7.6 light years respectively.
HD 39194 is a star located in the southern circumpolar constellation Mensa. It has an apparent magnitude of 8.07, making it readily visible in binoculars but not to the naked eye. The object is relatively close at a distance of 86 light years but is receding with a heliocentric radial velocity of 13.9 km/s.
Wolf 1069 is a red dwarf star located 31.2 light-years away from the Solar System in the constellation of Cygnus. The star has 17% the mass and 18% the radius of the Sun, a temperature of 3,158 K, and a slow rotation period of 150–170 days. It hosts one known exoplanet called Wolf 1069 b which could possibly sustain life.