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HD 74156 is a yellow dwarf star in the constellation of Hydra, 210 light years from the Solar System. It is known to be orbited by two giant planets.
HD 187123 is an 8th magnitude G-type main sequence star located approximately 150 light-years away in the constellation of Cygnus. Like our Sun, it is a yellow dwarf. Being at a distance of about 160 light-years it is not visible to the unaided eye. However, it should be easy target with binoculars or small telescope.
HD 217107 is a yellow subgiant star approximately 65 light-years away from Earth in the constellation of Pisces. Its mass is very similar to the Sun's, although it is considerably older. Two planets have been discovered orbiting the star: one is extremely close and completes an orbit every seven days, while the other is much more distant, taking eight years to complete an orbit.
HD 217107 c is an extrasolar planet approximately 64 light-years away from Earth in the constellation of Pisces. The planet was the second planet to be discovered orbiting the star HD 217107. HD 217107 c's existence was hypothesized in 1998 due to the eccentricity of the inner planet's orbit and confirmed in 2005 when radial velocity studies of the star indicated another, more distant and massive companion orbiting the star. The planet has an eccentric orbit lasting on order of a decade.
HD 11964 is a binary star system located 110 light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. The system is drifting closer to the Sun with a radial velocity of −9 km/s. Two extrasolar planets have been confirmed to orbit the primary.
HD 11964 c is an extrasolar planet approximately 110 light-years away in the constellation of Cetus. The planet was discovered in a close-orbit around the yellow subgiant star HD 11964. The planet has a minimum mass 35 times the mass of Earth and is located in a mildly eccentric orbit which takes almost 38 days to complete. HD 11964 c was a possible planet discovered on the same day as HD 11964 b in 2005. HD 11964 c was first proposed in a paper published in 2007, and finally confirmed with new data presented in a review of multi-planet systems which appeared on the arXiv preprint website in 2008.
HD 11964 b is an extrasolar planet, a gas giant like Jupiter approximately 110 light-years away in the constellation of Cetus. The planet orbits the yellow subgiant star HD 11964 in a nearly-circular orbit, taking over 5 years to complete a revolution around the star at a distance of 3.34 astronomical units.
HD 17156, named Nushagak by the IAU, is a yellow subgiant star approximately 255 light-years away in the constellation of Cassiopeia. The apparent magnitude is 8.17, which means it is not visible to the naked eye but can be seen with good binoculars. A search for a binary companion star using adaptive optics at the MMT Observatory was negative.
HD 68988 is a star in the northern constellation of Ursa Major. It has been given the proper name Násti, which means star in the Northern Sami language. The name was selected in the NameExoWorlds campaign by Norway, during the 100th anniversary of the IAU. HD 68988 is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.20. The star is located at a distance of 199 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −69 km/s and is predicted to come as close as 78 light-years in 617,000 years.
HD 24040 is a metal-rich G-type star located approximately 152 light-years away in the constellation of Taurus. In 2006 a long-period planet was discovered.
HD 66428 b is a long-period jovian exoplanet located approximately 179.3 light-years away in the constellation of Monoceros. It has a 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.
HIP 14810 c is an extrasolar planet approximately 165 light-years away in the constellation of Aries. This planet has mass at least 1.28 times that of Jupiter and orbits at 0.545 AU in an eccentric orbit. The planet was discovered by the N2K Consortium in 2006 and announced in a paper published in 2007. With the discovery of a third planet in the system which was announced in 2009, the parameters of this planet were revised.
HD 187123 b is a typical "hot Jupiter" located approximately 150 light-years away in the constellation of Cygnus, orbiting the star HD 187123. It has a mass about half that of Jupiter and it orbits in a very tight, round orbit around the star every three days.
HD 183263 b is an extrasolar planet orbiting the star HD 183263. This planet has a minimum mass of 3.6 times more than Jupiter and takes 625 days to orbit the star. The planet was discovered on January 25, 2005 using multiple Doppler measurements of five nearby FGK main-sequence stars and subgiants obtained during the past 4–6 years at the Keck Observatory in Mauna Kea, Hawaii. These stars, namely, HD 183263, HD 117207, HD 188015, HD 45350, and HD 99492, all exhibit coherent variations in their Doppler shifts consistent with a planet in Keplerian motion, and the results were published in a paper by Geoffrey Marcy et al. Photometric observations were acquired for four of the five host stars with an automatic telescope at Fairborn Observatory. The lack of brightness variations in phase with the radial velocities supports planetary-reflex motion as the cause of the velocity variations. An additional planet in the system was discovered later.
HD 108874 c is a gas giant discovered in 2005 which orbits beyond the star's habitable zone, and receives insolation 15.9% that of Earth. It has minimum mass similar to Jupiter, although since the inclination of the orbit is not known the true mass of this planet could be much greater. The planet is possibly in a 4 : 1 orbital resonance with HD 108874 b.
HD 24040 b is a long-period exoplanet taking approximately 3500 days to orbit at 4.6 astronomical units in an almost circular orbit. It has a minimum mass 4 times that of Jupiter.
HD 143361 b is an extrasolar planet located approximately 194 light-years away in the constellation of Norma, orbiting the 9th magnitude G-type main sequence star HD 143361. This planet has a minimum mass of 3.0 times that of Jupiter. Because the inclination is not known, the true mass is not known. This planet orbits at a distance of 2.0 AU with an orbital eccentricity of 0.18.
HD 183263 c is an exoplanet orbiting approximately 4.25 AU from the parent star HD 183263. This planet was announced by Wright et al. on December 8, 2008 using multiple observations in Lick and Keck Observatories earlier in that year. This planet was calculated to have minimum mass of 3.82 times more than Jupiter and takes 8.08 years to revolve around the star. The orbital distance varies from 3.17 to 5.33 AU, corresponding to the orbital eccentricity of 0.253.
References
- 1 2 3 4 5 Feng, Y. Katherina; et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal. 800 (1). 22. arXiv: 1501.00633 . Bibcode:2015ApJ...800...22F. doi:10.1088/0004-637X/800/1/22. S2CID 56390823.
- ↑ Wright, J. T.; et al. (2007). "Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars". The Astrophysical Journal. 657 (1): 533–545. arXiv: astro-ph/0611658 . Bibcode:2007ApJ...657..533W. doi:10.1086/510553. S2CID 35682784.
- ↑ Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal. 693 (2): 1084–1099. arXiv: 0812.1582 . Bibcode:2009ApJ...693.1084W. doi:10.1088/0004-637X/693/2/1084. S2CID 18169921.
