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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 fourteen years to complete an orbit.
HD 177830 is a 7th magnitude binary star system located approximately 205 light-years away in the constellation of Lyra. The primary star is slightly more massive than the Sun, but cooler being a type K star. Therefore, it is a subgiant clearly more evolved than the Sun. In visual light it is four times brighter than the Sun, but because of its distance, about 205 light years, it is not visible to the unaided eye. With binoculars it should be easily visible.
109 Piscium is a yellow hued G-type main-sequence star located about 108 light-years away in the zodiac constellation of Pisces. It is near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.27. The star is moving closer to the Earth with a heliocentric radial velocity of −45.5 km/s. It has one known exoplanet.
HD 185269 is a stellar triple system approximately 170 light-years away in the constellation Cygnus. It is easily visible to binoculars, but not the naked eye.
HD 118203 is a star located in the northern circumpolar constellation of Ursa Major. It has the proper name Liesma, which means flame, and it is the name of a character from the Latvian poem Staburags un Liesma. The name was selected in the NameExoWorlds campaign by Latvia, during the 100th anniversary of the IAU.
Kappa Coronae Borealis b is an extrasolar planet approximately 98 light-years away in the constellation of Corona Borealis. This planet was discovered by Johnson et al., who used the radial velocity method to detect wobbling of the star caused by a planet move around by its tug of gravity. It was first discovered in September 2007 and was published in November.
HD 192699 b, also named Khomsa, is an exoplanet located approximately 214 light-years away in the constellation of Aquila, orbiting the star HD 192699. This planet was discovered in April 2007, massing at least 2.5 times the mass of Jupiter (MJ). Despite its orbital distance more than that of Earth, the orbital period is less than a year, because the parent star is more massive than the Sun.
HD 210702 b is an exoplanet located approximately 177 light-years away in the constellation of Pegasus, orbiting the star HD 210702. This planet, together with HD 175541 b and HD 192699 b, are planets around intermediate mass stars that were announced in April 2007 by Johnson et al. It has at least twice the mass of Jupiter and it orbits with semimajor axis of 1.17 AU, corresponding to a period of 341.1 days.
HD 175541 b, also named Kavian, is a jovian planet located approximately 424 light-years away in the constellation of Serpens, orbiting the star HD 175541. This planet was discovered in April 2007. Despite the distance of planet to star slightly more than Earth to the Sun, the period is less than 300 days that orbits in an eccentric orbit, because the parent star is 65% more massive than the Sun.
HD 185269 b is a hot Jupiter extrasolar planet approximately 170 light years away in the constellation of Cygnus. The minimum mass is slightly less than Jupiter and the orbital period is about one week. Most hot Jupiters are thought to have undergone tidal circularization, making the eccentricity of HD 185269 b (e=0.3) unusual. Despite having a large transit probability, none have yet been detected by various photometric monitoring campaigns.
HD 17156 b, named Mulchatna by the IAU, is an extrasolar planet approximately 255 light-years away in the constellation of Cassiopeia. The planet was discovered orbiting the yellow subgiant star HD 17156 in April 2007. The planet is classified as a relatively cool hot Jupiter planet slightly smaller than Jupiter but slightly larger than Saturn. This highly-eccentric three-week orbit takes it approximately 0.0523 AU of the star at periastron before swinging out to approximately 0.2665 AU at apastron. Its eccentricity is about the same as 16 Cygni Bb, a so-called "eccentric Jupiter". Until 2009, HD 17156 b was the transiting planet with the longest orbital period.
HD 212771 b is an extrasolar planet orbiting the G-type star HD 212771 approximately 364 light years away in the constellation Aquarius.
HD 180902 b is an extrasolar planet orbiting the K-type star HD 180902 approximately 342 light years away in the constellation Sagittarius.
HD 4313 b is an extrasolar planet orbiting the K-type star HD 4313 approximately 447 light years away in the constellation Pisces. This planet was discovered using the Doppler spectroscopy method.
HD 163607 c is the outermost planet discovered to orbit a star HD 163607, a star somewhat brighter and older than the Sun. It was discovered using the radial velocity method, and was initially observed as part of the N2K Program. Its minimum mass is at least 2.4 of Jupiter's. It is located in its host star's habitable zone.
HD 179070, also known as Kepler-21, is a F-type subgiant star 354 light-years away in the constellation Lyra. A transiting exoplanet was discovered orbiting this star by the Kepler spacecraft. At a magnitude of 8.25 this was the brightest star observed by Kepler to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018.
HD 38801 b is an extrasolar, gas giant planet located in the constellation of Orion whose discovery was announced in 2009 and was made using the radial velocity method. The object, with a mass roughly 12 times that of Jupiter, is located 324 light years from Earth orbiting 1.65 astronomical units from its G-type star, HD 38801. HD 38801 b, besides being the only planet in its system also lies within the inner habitable zone and takes around 1.9 years, or 693.5 days to complete a full orbit.
HD 102956 b or Isagel is an extrasolar planet discovered in 2010 by a team of American astronomers led by John Johnson using Doppler spectroscopy and the Keck Observatory in Hawaii. HD 102956 b is in the orbit of host star HD 102956. The planet is at most the mass of Jupiter, orbiting every 6.5 days at a distance of 12 million km. HD 202956 b has a very circular orbit. The system is roughly 399 light years from us.
HD 108863 is a subgiant star, the primary of a binary star system 540 light-years away, belonging to spectral class K0. Its age is younger than the Sun's at 1.8±0.4 billion years. The primary star is slightly enriched in heavy elements, having 115% of solar abundance. The primary star does not have detectable flare activity.
HD 99706 is an orange-hued star in the northern circumpolar constellation of Ursa Major. With an apparent visual magnitude of 7.65, it is too dim to be visible to the naked eye but can be viewed with a pair of binoculars. Parallax measurements provide a distance estimate of approximately 480 light years from the Sun, and the Doppler shift shows it is drifting closer with a radial velocity of −30 km/s. It has an absolute magnitude of 2.12, indicating it would be visible to the naked eye as a 2nd magnitude star if it were located 10 parsecs away.
References
- 1 2 Giguere, Matthew J.; et al. (2012). "A High-eccentricity Component in the Double-planet System around HD 163607 and a Planet around HD 164509". The Astrophysical Journal. 744 (1): 4–13. arXiv: 1109.2955 . Bibcode: 2012ApJ...744....4G . doi: 10.1088/0004-637X/744/1/4 .
- 1 2 Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv: 1811.03043 . Bibcode:2019AJ....157..149L. doi: 10.3847/1538-3881/aaf5d0 .
