Related Research Articles
HD 89744 is an F-type subgiant star about 126 light years away in the constellation of Ursa Major. This star has 1.45 times the mass of the Sun, with a projected rotational velocity of 8.0 km s−1. In 2004, stellar companion HD 89744 B with a projected separation of 2,456 AU was detected. There are two known exoplanets orbiting this star.
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 4203 is a single star in the equatorial constellation of Pisces, near the northern constellation border with Andromeda. It has a yellow hue and is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.70. The distance to this object is 266 light years based on parallax, but it is drifting closer to the Sun with a radial velocity of −14 km/s.
Kappa Coronae Borealis, Latinized from κ Coronae Borealis, is a star approximately 98 light years away in the constellation of Corona Borealis. The apparent magnitude is +4.82 and the absolute magnitude is +2.35. It is an orange K-type subgiant star of spectral type K1IV, meaning it has nearly completely exhausted its hydrogen supply in its core. It is 1.32 times as massive as the Sun yet has brightened to 11.6 times its luminosity. Around 2.5 billion years old, it was formerly an A-type main sequence star.
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 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 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.
41 Lyncis, also designated HD 81688 and named Intercrus, is a fifth magnitude star located in the northern constellation of Ursa Major. An extrasolar planet is thought to be orbiting the star.
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 7924 is a single star located 55.5 light years away from the Sun in the northern constellation of Cassiopeia, near the northern constellation border with Cepheus. It has an orange hue and is only visible by means of binoculars or a telescope due to a low apparent visual magnitude of 7.167. The star is drifting closer to the Sun with a radial velocity of –22.7 km/s, and is expected to approach to within 9.3 light-years in around 711,700 years.
HD 1461 is a star in the equatorial constellation of Cetus, near the western constellation border with Aquarius. It has the Gould designation 32 G. Ceti, while HD 1461 is the Henry Draper Catalogue identifier. This object has a yellow hue and is a challenge to view with the naked eye, having an apparent visual magnitude of 6.47. The star is located at a distance of 76.5 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −10 km/s.
Gliese 649 is a red dwarf star in the constellation of Hercules, located roughly 34 light years from the Sun. The star has been found to host an extrasolar planet.
24 Sextantis, often abbreviated as 24 Sex, is the Flamsteed designation of a 7th-magnitude star located approximately 236 light years away in the constellation of Sextans. At an apparent visual magnitude of 6.61, this star can only be viewed from rural skies under good seeing conditions.
11 Comae Berenices is a binary star system in the northern constellation of Coma Berenices, located in the sky, east and slightly north of Denebola in Leo, but not nearly as far east as ε Virginis in Virgo. It is about a degree from the elliptical galaxy M85 and two degrees north of the spiral galaxy M100. Based upon an annual parallax shift of 10.7104 mas, the star is located 305 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.72. This body is moving away from the Sun with a heliocentric radial velocity of +44 km/s.
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.
75 Ceti is a single star in the equatorial constellation of Cetus with at least one planet. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.36. The star is located 271 light years distant from the Sun, based on parallax, but is drifting closer with a radial velocity of −6 km/s.
HD 5608 is an orange-hued star in the northern constellation of Andromeda with one known planet, HD 5608 b. It is a dim star near the lower limit of visibility to the naked eye, having an apparent visual magnitude of +5.98. The distance to HD 5608, as estimated from an annual parallax shift of 17.18 mas, is 190 light years. It is moving closer to the Earth with a heliocentric radial velocity of −23 km/s, and is expected to make its closest approach in 1.285 million years when it comes to within 124 light-years.
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.
References
- 1 2 3 4 5 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.
- 1 2 3 Sato, Bun'ei; et al. (2012). "Substellar Companions to Seven Evolved Intermediate-Mass Stars". Publications of the Astronomical Society of Japan. 64 (6). 135. arXiv: 1207.3141 . Bibcode: 2012PASJ...64..135S . doi: 10.1093/pasj/64.6.135 .
- 1 2 3 4 5 von Braun, Kaspar; et al. (2014). "Stellar diameters and temperatures – V. 11 newly characterized exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 438 (3): 2413–2425. arXiv: 1312.1792 . Bibcode: 2014MNRAS.438.2413V . doi: 10.1093/mnras/stt2360 .
- ↑ "HD 210702". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-09-15.
- ↑ 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 .
- ↑ 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. S2CID 102486961.
- "HR 8461". webviz.u-strasbg.fr/.
