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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 175541 is an intermediate-mass subgiant star in the constellation Serpens. That means when this star was a main-sequence, it was an A-type star. It is an 8th magnitude star about 424 light years from Earth. Despite its distance of over 100 ly, It was given the number 736 in the Gliese Catalogue of Nearby Stars.
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 192699 is a yellow subgiant star located approximately 214 light-years away in the constellation of Aquila. It has the apparent magnitude of 6.45. Based on its mass of 1.68 solar, it was an A-type star when it was a main-sequence. In April 2007, a planet was announced orbiting the star, together with HD 175541 b and HD 210702 b.
HD 210702 is an orange subgiant star located approximately 177 light-years away in the constellation of Pegasus. With a mass of 1.8 times that of the Sun, the star spent its main-sequence life as an A-type star. The visual luminosity is 11.38 times that of the Sun and the magnitude is near the naked-eye limit, but binoculars can easily see it.
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 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 175541 b 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 our 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.
6 Lyncis is a star in the northern constellation of Lynx, located approximately 179 light years from Earth. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.86. This object is moving away from the Earth with a heliocentric radial velocity of +40 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.341 arc seconds per annum.
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 181342 b is an extrasolar planet orbiting the K-type star HD 181342 approximately 394 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 180902 is a binary star approximately 342 light years away in the constellation Sagittarius. The primary is a K-type star while the nature of the secondary is unknown since it has only been detected by its effect on the radial velocity of the primary.
HD 181342 is a star in the constellation of Sagittarius. With an apparent magnitude of 7.55, it cannot be seen with the naked eye. Parallax measurements made by Gaia spacecraft put the star at a distance of 394 light-years away.
HD 98219 is a subgiant star in the constellation Crater. It has a confirmed exoplanet. At around 4 billion years old, it is a star around 1.3 times as massive as the Sun that has cooled and expanded to 4.5 times the Sun's diameter, brightening to be around 11 times as luminous. The International Astronomical Union (IAU) gave the opportunity to Honduras to name the star Hunahpú. Hunahpú was one of the twin gods who became the Sun in K'iche' (Quiché) Mayan mythology.
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 131496 is an evolved subgiant star in the constellation Boötes. With an apparent visual magnitude of 7.9 it is too faint to be visible to the naked eye. Stars like HD 131496 are sometimes referred to as "retired A-stars", since they would have been A-type stars while on the main sequence. This name is most commonly used in connection with the search for extrasolar planets, where they are useful because these evolved stars are cooler and have more spectral lines than their main sequence counterparts, making planet detection easier.
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.
References
- 1 2 Johnson, John Asher; et al. (2007). "Retired A Stars and Their Companions: Exoplanets Orbiting Three Intermediate-Mass Subgiants". The Astrophysical Journal. 665 (1): 785–793. arXiv: 0704.2455 . Bibcode: 2007ApJ...665..785J . doi: 10.1086/519677 .
- 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.
- ↑ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
- "HR 8461". webviz.u-strasbg.fr/.
