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HD 209458 b, which is also nicknamed Osiris after the Egyptian god, is an exoplanet that orbits the solar analog HD 209458 in the constellation Pegasus, some 159 light-years from the Solar System. The radius of the planet's orbit is 0.047 AU, or one-eighth the radius of Mercury's orbit. This small radius results in a year that is 3.5 Earth-days long and an estimated surface temperature of about 1,000 °C. Its mass is 220 times that of Earth and its volume is some 2.5 times greater than that of Jupiter. The high mass and volume of HD 209458 b indicate that it is a gas giant.
14 Herculis or 14 Her is the Flamsteed designation of a K-type main-sequence star approximately 58.5 light-years away in the constellation Hercules. Because of its apparent magnitude, the star cannot be seen with the naked eye. As of 2006, it is thought that 14 Herculis has two extrasolar planets in orbit around the star.
HD 169830 is a star in the southern constellation of Sagittarius. It has a yellow-white hue and is dimly visible to the naked eye with an apparent visual magnitude of +5.90. The star is located at a distance of 120 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −17.3 km/s, and is predicted to come as close as 20.7 ly (6.4 pc) in 2.08 million years. HD 169830 is known to be orbited by two large Jupiter-like exoplanets.
HD 150706 is a 7th magnitude star in the constellation of Ursa Minor. It is a remarkably Sun-like yellow dwarf being only 6% less massive than the Sun.
HD 189733, also catalogued as V452 Vulpeculae, is a binary star system approximately 64.5 light-years away in the constellation of Vulpecula. The primary star is suspected to be an orange dwarf star, while the secondary star is a red dwarf star. Given that this system has the same visual magnitude as HD 209458, it promises much for the study of close transiting extrasolar planets. The star can be found with binoculars 0.3 degrees east of the Dumbbell Nebula (M27).
HD 70642 is a star with an exoplanetary companion in the southern constellation of Puppis. It has an apparent visual magnitude of +7.17, which is too dim to be readily visible to the naked eye. The system is located at a distance of 95.5 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +49.3 km/s. It came to within 55.3 ly of the Solar System some 329,000 years ago.
Pi Mensae, also known as HD 39091, is a yellow dwarf star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 light-years away. The star is slightly larger than the Sun in terms of mass, size, luminosity, temperature and metallicity, and is about 730 million years younger. It hosts three known planets.
Pi Mensae b, also known as HD 39091 b, is an extrasolar planet approximately 59 light-years away in the constellation of Mensa. The planet was announced orbiting the yellow main-sequence star Pi Mensae in October 2001.
HD 154345 is a star in the northern constellation of Hercules. With an apparent visual magnitude of +6.76 it is a challenge to view with the naked eye, but using binoculars it is an easy target. The distance to this star is 59.6 light years based on parallax, but it is drifting closer with a radial velocity of −47 km/s. At least one exoplanet is orbiting this star.
HD 114762 b is a small red dwarf star, in the HD 114762 system, formerly thought to be a massive gaseous extrasolar planet, approximately 126 light-years (38.6 pc) away in the constellation of Coma Berenices. This optically undetected companion to the late F-type main-sequence star HD 114762 was discovered in 1989 by Latham, et al., and confirmed in an October 1991 paper by Cochran, et al. It was thought to be the first discovered exoplanet
HD 117207 is a star in the southern constellation Centaurus. With an apparent visual magnitude of 7.24, it is too dim to be visible to the naked eye but can be seen with a small telescope. Based upon parallax measurements, it is located at a distance of 105.4 light-years from the Sun. The star is drifting closer with a radial velocity of −17.4 km/s. It has an absolute magnitude of 4.67.
HD 66428 b is a long-period jovian exoplanet located approximately 174 light-years away in the constellation of Monoceros. It has a minimum mass of 2.82 MJ and takes 1973 days or 5.402 years to orbit around its solar-type star HD 66428. The average distance is 3.18 AU, about half the distance between Mars and Jupiter. This planet is a so-called eccentric Jupiter with an orbital eccentricity of 0.465. At periastron, the distance is 1.70 AU and at apastron, the distance is 4.66 AU. In 2022, the inclination and true mass of HD 66428 b were measured via astrometry.
HD 117207 b is an exoplanet orbiting at 3.77 astronomical units around HD 117207, taking about 7.14 years to complete its orbit. Its orbit has a low to moderate eccentricity. This planet was announced in January 2005 by Marcy at the Keck Observatory. HD 117207 b has a minimum mass of 1.88 Jupiter masses, and in 2023 its inclination and true mass were determined via astrometry.
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.
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 May 2023, there are 5,366 confirmed exoplanets in 3,962 planetary systems, with 856 systems having more than one planet. This is a list of the most notable discoveries.
HD 3167 is a single, orange-hued star in the zodiac constellation of Pisces that hosts a system with three exoplanets. The star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.97. The distance to HD 3167 can be determined from its annual parallax shift of 21.1363 mas as measured by the Gaia space observatory, yielding a range of 154 light years. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.204″ per year. Since it was first photographed during the Palomar observatory sky survey in 1953, it had moved over 12.5″ by 2017. The star is moving away from the Earth with an average heliocentric radial velocity of +19.5 km/s.
References
- 1 2 Carter, Brad D.; et al. (2003). "A Planet in a Circular Orbit with a 6 Year Period". The Astrophysical Journal Letters. 593 (1): L43–L46. arXiv: astro-ph/0307066 . Bibcode:2003ApJ...593L..43C. doi:10.1086/378185. S2CID 119338858.
- 1 2 3 Xiao, Guang-Yao; Liu, Yu-Juan; et al. (May 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics . 23 (5): 055022. arXiv: 2303.12409 . Bibcode:2023RAA....23e5022X. doi:10.1088/1674-4527/accb7e.
