Gliese 176 b

Last updated
Gliese 176 b
Discovery
Discovered by Endl, [1] Forveille et al. [2]
Discovery dateSeptember 7, 2007
radial velocity
Orbital characteristics
0.066±0.001 AU
Eccentricity 0.148+0.249
−0.036
8.776+0.001
−0.002
d
2450839.760
150.6+42.2
−104.5
Semi-amplitude 4.49+1.00
−0.23
Star Gliese 176
Physical characteristics
Temperature ~450 [2]
    Gliese 176 b Planet Gliese 176 b.png
    Gliese 176 b

    Gliese 176 b is a super-Earth exoplanet approximately 31 light years away in the constellation of Taurus. This planet orbits very close to its parent red dwarf star Gliese 176 (also called "HD 285968").

    The initial announcement confused the planetary periodicity with the stellar periodicity of 40 days, thus giving a 10.24 day period for a 25 Earth-mass planet. [1] Subsequent readings filtered out the star's rotation, giving a more accurate reading of the planet's orbit and minimum mass.

    The planet orbits inside the inner magnetosphere of its star. The quoted temperature of 450 K is a "thermal equilibrium" temperature. [2]

    It is projected to be dominated by a rocky core, but the true mass is unknown. If the orbit is oriented such that we are viewing it at a nearly face-on angle, the planet may be significantly more massive than the lower limit. If so, it may have attracted a gas envelope like Uranus or Gliese 436 b. [2]

    Related Research Articles

    <span class="mw-page-title-main">Gliese 876</span> Star in the constellation Aquarius

    Gliese 876 is a red dwarf star 15.2 light-years away from Earth in the constellation of Aquarius. It is one of the closest known stars to the Sun confirmed to possess a planetary system with more than two planets, after GJ 1061, YZ Ceti, Tau Ceti, and Wolf 1061; as of 2018, four extrasolar planets have been found to orbit the star. The planetary system is also notable for the orbital properties of its planets. It is the only known system of orbital companions to exhibit a near-triple conjunction in the rare phenomenon of Laplace resonance. It is also the first extrasolar system around a normal star with measured coplanarity. While planets b and c are located in the system's habitable zone, they are giant planets believed to be analogous to Jupiter.

    Gliese 581 is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20.5 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is the 101st closest known star system to the Sun. Gliese 581 is one of the oldest, least active M dwarfs known. Its low stellar activity improves the likelihood of its planets retaining significant atmospheres, and lessens the sterilizing impact of stellar flares.

    <span class="mw-page-title-main">Gliese 581b</span> Gas giant orbiting Gliese 581

    Gliese 581b or Gl 581b is an exoplanet orbiting within the Gliese 581 system. It is the first planet discovered of three confirmed in the system so far, and the second in order from the star.

    <span class="mw-page-title-main">Gliese 436 b</span> Hot Neptune exoplanet orbiting Gliese 436

    Gliese 436 b is a Neptune-sized exoplanet orbiting the red dwarf Gliese 436. It was the first hot Neptune discovered with certainty and was among the smallest-known transiting planets in mass and radius, until the much smaller Kepler exoplanet discoveries began circa 2010.

    <span class="mw-page-title-main">Gliese 581c</span> Super-Earth exoplanet orbiting Gliese 581

    Gliese 581c is an exoplanet orbiting within the Gliese 581 system. It is the second planet discovered in the system and the third in order from the star. With a mass at least 5.5 times that of the Earth, it is classified as a super-Earth.

    <span class="mw-page-title-main">Gliese 581d</span> Contested super-Earth orbiting Gliese 581

    Gliese 581d was a candidate extrasolar planet orbiting within the Gliese 581 system, approximately 20.4 light-years away in the Libra constellation. It was the third planet claimed in the system and the fourth or fifth in order from the star. Multiple subsequent studies found that the planetary signal in fact originates from stellar activity, and thus the planet does not exist.

    <span class="mw-page-title-main">Super-Earth</span> Planet with a mass between Earth and Uranus

    A Super-Earth is a type of exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term.

    Gliese 176 is a small star with an orbiting exoplanet in the constellation of Taurus. With an apparent visual magnitude of 9.95, it is too faint to be visible to the naked eye. It is located at a distance of 30.9 light years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 26.4 km/s.

    <span class="mw-page-title-main">Gliese 581e</span> Terrestrial planet orbiting Gliese 581

    Gliese 581e or Gl 581e is an exoplanet orbiting within the Gliese 581 system, located approximately 20.4 light-years away from Earth in the Libra constellation. It is the third planet discovered in the system and the first in order from the star.

    Gliese 676 is a 10th-magnitude wide binary system of red dwarfs that has an estimated minimum separation of 800 AU with an orbital period of greater than 20,000 years. It is located approximately 54 light years away in the constellation Ara. In 2009, a gas giant was found in orbit around the primary star, in addition to its confirmation in 2011 there was also a strong indication of a companion; the second gas giant was characterised in 2012, along with two much smaller planets.

    <span class="mw-page-title-main">Discoveries of exoplanets</span> Detecting planets located outside the Solar System

    An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 1 January 2024, there are 5,576 confirmed exoplanets in 4,113 planetary systems, with 887 systems having more than one planet. This is a list of the most notable discoveries.

    <span class="mw-page-title-main">HD 85512 b</span> Terrestrial exoplanet orbiting HD 85512

    HD 85512 b is a currently-disputed exoplanet orbiting HD 85512, a K-type main-sequence star approximately 37 light-years from Earth in the constellation of Vela.

    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.

    Mikko Tuomi is a Finnish astronomer from the University of Hertfordshire, most known for his contributions to the discovery of a number of exoplanets, among them the Proxima Centauri b which orbits the closest star to the Sun. Mikko Tuomi was the first to find indications of the existence of Proxima Centauri b in archival observation data. Other exoplanets to whose discovery or study Tuomi has contributed include HD 40307, HD 154857 c, Kapteyn c, Gliese 682 c, HD 154857, Gliese 221, Gliese 581 g and the planetary system orbiting Tau Ceti. He has led the development of new data analysis techniques for distinguishing observations caused by natural activity of the star and those caused by planets orbiting them.

    Luyten b is a confirmed exoplanet, likely rocky, orbiting within the habitable zone of the nearby red dwarf Luyten's Star. It is the fourth-closest potentially habitable exoplanet known, at a distance of 12 light-years. Only Proxima Centauri b, Ross 128 b, and GJ 1061 d are closer. Discovered alongside Gliese 273c in June 2017, Luyten b is a super-Earth of around 2.89 times the mass of Earth and receives only 6% more starlight than Earth, making it one of the best candidates for habitability.

    <span class="mw-page-title-main">LTT 1445</span> Star system in the constellation Eridanus

    LTT 1445 is a triple M-dwarf system 22.4 light-years distant in the constellation Eridanus. The primary LTT 1445 A hosts two exoplanets—one discovered in 2019 that transits the star every 5.36 days, and another found in 2021 that transits the star every 3.12 days, close to a 12:7 resonance. As of October 2022 it is the second closest transiting exoplanet system discovered, with the closest being HD 219134 bc.

    Gliese 367 is a red dwarf star 30.7 light-years from Earth in the constellation of Vela. It is suspected to be a variable with amplitude 0.012 stellar magnitude and period 5.16 years. A stellar multiplicity survey in 2015 failed to detect any stellar companions to Gliese 367. It hosts three known exoplanets, Gliese 367 b, c & d.

    References

    1. 1 2 Endl, Michael; et al. (2008). "An m sin i = 24 M Planetary Companion to the Nearby M Dwarf GJ 176". The Astrophysical Journal. 673 (2): 1165–1168. arXiv: 0709.0944 . Bibcode:2008ApJ...673.1165E. doi:10.1086/524703.
    2. 1 2 3 4 Forveille, Thierry; Bonfils, Xavier; Delfosse, Xavier; Gillon, Michaël; Udry, Stéphane; Bouchy, François; Lovis, Christophe; Mayor, Michel; Pepe, Francesco; Perrier, Christian; Queloz, Didier; Santos, Nuno C.; Bertaux, Jean-Loup (2009). "The HARPS search for southern extra-solar planets. XIV. Gl 176b, a super-Earth rather than a Neptune, and at a different period". Astronomy and Astrophysics. 493 (2): 645–650. arXiv: 0809.0750 . Bibcode:2009A&A...493..645F. doi:10.1051/0004-6361:200810557.