Discovery | |
---|---|
Discovered by | Moutou et al. [1] |
Discovery site | La Silla Observatory |
Discovery date | October 26, 2008 |
Doppler spectroscopy (HARPS) | |
Orbital characteristics | |
1.28 ± 0.01 AU (191,500,000 ± 1,500,000 km) | |
Eccentricity | 0.34 ± 0.021 |
499.4 ± 3.6 d 1.367 ± 0.010 y | |
Average orbital speed | 28.0 |
2,454,502 ± 4.1 | |
308.2 ± 2.4 | |
Star | HD 153950 |
HD 153950 b, also known as Trimobe, is an extrasolar planet located approximately 162 light-years away. This planet was discovered on October 26, 2008 by Moutou et al. using the HARPS spectrograph on ESO's 3.6 meter telescope installed at La Silla Observatory in Atacama Desert, Chile. [1]
The planet HD 153950 b is named Trimobe. The name was selected in the NameExoWorlds campaign by Madagascar, during the 100th anniversary of the IAU. Trimobe is a rich ogre from Malagasy tales. [2] [3]
HD 153950 b is a Jupiter-size exoplanet. The estimated minimum mass is 2.73 times the mass of Jupiter. The planet has been found to orbit its host star every 500 days at a distance of 1.28 AU, which is approximately 28% more of the mean distance between the Sun and the Earth. HD 153950 b has a mildly elliptical orbit, given its orbital eccentricity of 0.34. [4]
The temperature of the exoplanet is likely to vary during its orbit, temperatures would likely range from 275–375 K (2–102 °C; 35–215 °F) as it approaches its periastron/apastron of its orbit. This would also likely apply to a potentially habitable hypothetical moon orbiting the gas giant exoplanet (see below).
HD 153950 is an F-type star with a mass that is 1.13 times the mass of the Sun and a size that is 1.34 times the radius of the Sun. In other words, it is slightly more massive and slightly larger than the Sun is. With an effective temperature of 6076 K, HD 205739 is also hotter than the Sun, although it is younger, at an estimated age of 4.3 billion years, 250–300 million years younger than the Sun. [4] The star is almost the same as the Sun in terms of metal; its measured metallicity is [Fe/H] = -0.01. [4] HD 153950 cannot be seen from Earth with the naked eye because the star has an apparent magnitude (V) of 7.39. [4]
HD 153950 b is located within the habitable zone of its star. The exoplanet, with a mass of 2.73 MJ, is too massive to be rocky, and because of this the planet itself is not expected to habitable. However, based on a probable 10−4 fraction of the planet mass as a satellite, [5] it may have a large enough moon with a sufficient atmosphere and pressure, and liquid water at its surface, potentially making it habitable. [6] On the other hand, this mass can be distributed into many small satellites as well.
HD 153950's designation is from the Henry Draper catalogue. The star was also observed by Hipparcos , which released its catalogue in 1997. The observations that led to the discovery of the planet HD 153950 b started when the N2K Consortium started an extended search for planets around 300 stars not usually targeted by Doppler spectroscopy surveys. In the case of HD 153950, the star was observed using telescopes at the La Silla Observatory in Chile.
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not then recognized as such. The first confirmation of the detection occurred in 1992. A different planet, first detected in 1988, was confirmed in 2003. According to statistics from the NASA Exoplanet Archive, As of 17 October 2024, there are 5,780 confirmed exoplanets in 4,314 planetary systems, with 969 systems having more than one planet. The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and to give more insight into their traits, such as their composition, environmental conditions, and potential for life.
2M1207b is a planetary-mass object orbiting the brown dwarf 2M1207, in the constellation Centaurus, approximately 170 light-years from Earth. It is one of the first candidate exoplanets to be directly observed. It was discovered in April 2004 by the Very Large Telescope (VLT) at the Paranal Observatory in Chile by a team from the European Southern Observatory led by Gaël Chauvin. It is believed to be from 5 to 6 times the mass of Jupiter and may orbit 2M1207 at a distance roughly as far from the brown dwarf as Pluto is from the Sun.
Gliese 876 b is an exoplanet orbiting the red dwarf Gliese 876. It completes one orbit in approximately 61 days. Discovered in June 1998, Gliese 876 b was the first planet to be discovered orbiting a red dwarf.
HD 69830 d is an exoplanet likely orbiting within the habitable zone of the star HD 69830, the outermost of three such planets discovered in the system. It is located approximately 40.7 light-years (12.49 parsecs, or 3.8505×1014 km) from Earth in the constellation of Puppis. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
Stéphane Udry is an astronomer at the Geneva Observatory in Switzerland, whose current work is primarily the search for extra-solar planets. He and his team, in 2007, discovered a possibly terrestrial planet in the habitable zone of the Gliese 581 planetary system, approximately 20 light years away in the constellation Libra. He also led the observational team that discovered HD 85512 b, another most promisingly habitable exoplanet.
HD 16175 b is an exoplanet located approximately 195.7 light-years away in the constellation of Andromeda, orbiting the star HD 16175. This planet has a minimum mass 4.8 times that of Jupiter; the true mass was initially unknown since the inclination of the orbit was unknown. This planet orbits at about 2.2 astronomical units, taking 2.73 years to revolve around the star. The orbit of the planet is highly elliptical with an eccentricity of 0.64. In 2023, the inclination and true mass of HD 16175 b were determined via astrometry.
BD-17°63 b, formally named Finlay, is an exoplanet located approximately 112.5 light-years away in the constellation of Cetus, orbiting the 10th magnitude K-type main sequence star BD−17 63. This planet has a minimum mass of 5.1 MJ and orbits at a distance of 1.34 astronomical units from the star. The distance ranges from 0.62 AU to 2.06 AU, corresponding to the eccentricity of 0.54. One revolution takes about 656 days.
HD 145377 b is an extrasolar planet located approximately 180 light-years away This planet was discovered on October 26, 2008 by Moutou et al. using the HARPS spectrograph on ESO's 3.6 meter telescope installed at La Silla Observatory in Atacama Desert, Chile.
HD 73267 b is an extrasolar planet located approximately 164 light-years away. This planet was discovered on October 26, 2008 by Moutou et al. using the HARPS spectrograph on ESO's 3.6 meter telescope installed at La Silla Observatory in Atacama Desert, Chile. In 2022, the inclination and true mass of HD 73267 b were measured via astrometry.
HD 20868 b is an extrasolar planet located approximately 156 light-years away in the constellation of Fornax, orbiting the 10th magnitude K-type subgiant star HD 20868. This planet has a minimum mass of 1.99 times more than Jupiter and orbits at a distance of 0.947 AU. This planet takes 380.85 days or 12.5 months to revolve around the star with an eccentricity of 0.75, one of the most eccentric of any known extrasolar planets. At periastron, the distance is 0.237 AU and at apastron, the distance is 1.66 AU.
HD 131664 is an 8th magnitude star in the southern constellation of Apus with an orbiting brown dwarf or stellar companion. Parallax measurements by the Gaia space observatory provide an estimated distance of 172.5 light years from the Earth. The system is moving further away with a baseline heliocentric radial velocity of +35 km/s.
HD 43848 is a 9th magnitude K-type subgiant star located approximately 123 light-years away in the constellation of Columba. The star is less massive than the Sun.
HD 20868 is a star in the southern constellation Fornax. With an apparent visual magnitude of 9.92, it is much too dim to be visible to the naked eye. Parallax measurements give a distance estimate of 156 light years from the Sun. It is drifting further away with a radial velocity of +46.2 km/s, having come to within about 124 ly around 312,000 years ago.
HD 73267 is a star in the southern constellation Pyxis, near the western constellation border with Puppis. It has an apparent visual magnitude of 8.889 and can be viewed with a small telescope. The distance to HD 73267 is 164 light years based on parallax, and it is drifting further away with a radial velocity of +51.8 km/s. It has an absolute magnitude of 5.24.
BD−17 63 is a 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.
HD 145377 is a star in the southern constellation Scorpius. It has an apparent visual magnitude of 8.10 and can be viewed with a small telescope. The star is located at a distance of 175 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +11.6. The absolute magnitude of this star is 4.31, indicating it would be visible to the naked eye if it were at a distance of 10 parsecs.
HD 153950 is a star in the southern constellation of Scorpius, positioned about 1.2° to the west of Eta Scorpii. It has the proper name Rapeto, which was selected in the NameExoWorlds campaign by Madagascar, during the 100th anniversary of the IAU. Rapeto is a giant creature from Malagasy tales. This star is visible in a small telescope, having an apparent visual magnitude of 7.39. It is located at a distance of 158 light years from the Sun based on parallax. The star is drifting further away with a radial velocity of 33.2 km/s.
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 24 July 2024, there are 7,026 confirmed exoplanets in 4,949 planetary systems, with 1007 systems having more than one planet. This is a list of the most notable discoveries.
WASP-43 is a K-type star about 284 light-years away in the Sextans constellation. It is about half the size of the Sun, and has approximately half the mass. WASP-43 has one known planet in orbit, a Hot Jupiter called WASP-43b. At the time of publishing of WASP-43b's discovery on April 15, 2011, the planet was the most closely orbiting Hot Jupiter discovered. The small orbit of WASP-43b is thought to be caused by WASP-43's unusually low mass. WASP-43 was first observed between January and May 2009 by the SuperWASP project, and was found to be cooler and slightly richer in metals than the Sun. WASP-43 has also been found to be an active star that rotates at a high velocity.
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