| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 20h 09m 28.30936s [1] |
| Declination | +52° 16′ 34.8000″ [1] |
| Apparent magnitude (V) | 8.08±0.01 [2] |
| Characteristics | |
| Spectral type | rG0V [3] |
| B−V color index | +0.63 [2] |
| Astrometry | |
| Radial velocity (Rv) | −15.33±0.13 [1] km/s |
| Proper motion (μ) | RA: 114.022±0.022 mas/yr [1] Dec.: 91.296±0.022 mas/yr [1] |
| Parallax (π) | 15.1975 ± 0.0182 mas [1] |
| Distance | 214.6 ± 0.3 ly (65.80 ± 0.08 pc) |
| Absolute magnitude (MV) | +3.89 [4] |
| Details | |
| Mass | 1.1±0.1 [5] M☉ |
| Radius | 1.48+0.14 −0.13 [6] R☉ |
| Luminosity | 2.23±0.16 [7] L☉ |
| Surface gravity (log g) | 4.15±0.15 [6] cgs |
| Temperature | 5,894+155 −86 [5] K |
| Metallicity [Fe/H] | +0.30±0.02 [7] dex |
| Rotation | 20.6±6.9 d [7] |
| Rotational velocity (v sin i) | 3.3 [7] km/s |
| Age | 2.9±0.4 [7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 191806 is a star located in the northern constellation Cygnus. With an apparent magnitude of 8.093, it's undetectable with the naked eye, but can be seen with binoculars. HD 191806 is currently placed at a distance of 215 light years based on parallax measurements and is drifting towards the Solar System with a spectroscopic radial velocity of −15.28 km/s .
HD 191806 has a stellar classification of G0V, [3] indicating that it is a G-type main sequence star. It has 110% the mass of the Sun [5] and a slightly enlarged radius of 1.48 R☉ . [6] It radiates at 2.23 times the luminosity of the Sun [7] from its photosphere at an effective temperature of 5,894 K , [5] giving a yellow hue. HD 191806 is estimated to be about 3 billion years old and has a metallicity nearly twice of the Sun's. [7] It spins with a projected rotational velocity of 3.3 km/s , which corresponds to a rotational period of 21 days. [7]
Observations for exoplanets orbiting the star began in 2007 when it was selected by the N2K Consortium as a potential host due to its high metallicity. [9] After ten years of, a team of astronomers found a super Jupiter orbiting the star. [7] The star has a secular acceleration of >11 km/s , suggesting either the presence of a stellar companion or another planet. [7] In 2022, the inclination and true mass of HD 191806 b were measured via astrometry. [10]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (years) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 9.334+0.919 −0.852 MJ | 2.749+0.106 −0.118 | 4.390+0.027 −0.031 | 0.213+0.029 −0.028 | 66.519+5.830 −4.851 ° | — |
HD 88133 is a yellow star with an orbiting exoplanet in the equatorial constellation of Leo. It has an apparent visual magnitude of 8.01, which is too faint to be visible to the naked eye. With a small telescope it should be easily visible. The distance to this system, as measured through parallax, is 240 light years, but it is slowly drifting closer with a radial velocity of −3.6 km/s.
HD 63454, formally named Ceibo, is a star located in the southern circumpolar constellation Chamaeleon near the border with Mensa. To see the star, one needs a small telescope because it has an apparent magnitude of 9.36, which is below the limit for naked eye visibility. The object is located relatively close at a distance of 123 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 33.8 km/s. At its current distance, HD 63454's brightness is diminished by two tenths of a magnitude due to interstellar dust. It has an absolute magnitude of +6.68.
HD 125612 is a binary star system with three exoplanetary companions in the equatorial constellation of Virgo. It is too dim to be visible to the naked eye, having an apparent visual magnitude of 8.31. The system is located at a distance of 188 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −18 km/s.
HD 66428 is a G-type main sequence star located approximately 174 light-years away in the constellation of Monoceros. This star is similar to the Sun with an apparent magnitude of 8.25, an effective temperature of 5705 ± 27 K and a solar luminosity 1.28. Its absolute magnitude is 11.1 while its U-V color index is 0.71. It is considered an inactive star and it is metal-rich . This star has a precise mass of 1.14552 solar masses. This precision comes from the Corot mission that measured asteroseismology.
HD 107148 is a wide binary star system in the constellation of Virgo. A pair of exoplanets have been confirmed in orbit around the brighter star. This system is located at a distance of 161 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 25.2 K. Although having an absolute magnitude of 4.47, at that range the system is too faint to be visible with the naked eye, having an apparent visual magnitude of 8.01.
HD 11506 is a star in the equatorial constellation of Cetus. It has a yellow hue and can be viewed with a small telescope but is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.51. The distance to this object is 167 light-years based on parallax, but it is drifting closer to the Sun with a radial velocity of −7.5 km/s. It has an absolute magnitude of 3.94.
HD 43691 is a star with an orbiting exoplanet in the constellation Auriga. With an apparent visual magnitude of 8.03, it is too faint to be visible to the naked eye. This system is located at a distance of 279 light years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −29 km/s.
HD 30177 is a single star with a pair of orbiting exoplanets in the southern constellation Dorado. Based on parallax measurements, it is located at a distance of 181 light years from the Sun. It has an absolute magnitude of 4.72, but at that distance the star is too faint to be viewed by the naked eye with an apparent visual magnitude of 8.41. The star is drifting further away with a radial velocity of 62.7 km/s.
HD 4113 is a dual star system in the southern constellation of Sculptor. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.88. The distance to this star, as estimated by parallax measurements, is 137 light years. It is receding away from the Sun with a radial velocity of +5 km/s.
HD 109749 is a binary star system about 206 light years away in the constellation of Centaurus. The pair have a combined apparent visual magnitude of 8.08, which is too faint to be visible to the naked eye. The primary component has a close orbiting exoplanet companion. The system is drifting closer with a heliocentric radial velocity of −13.2 km/s.
HD 149143, also called Rosalíadecastro, is a star with a close orbiting exoplanet in the Ophiuchus constellation. Its apparent visual magnitude is 7.89 and the absolute magnitude is 3.87. The system is located at a distance of 239 light years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 12 km/s.
HD 139357 is a 6th magnitude K-type giant star located approximately 370 light years from Earth, visible in the constellation Draco. Its mass is four thirds that of the Sun but its radius is 11.47 times larger. However, despite being a giant star, it is only 3.07 billion years old, which is younger than the Sun.
HD 86264 is a single star with an exoplanetary companion in the equatorial constellation of Hydra. It is too faint to be readily visible to the naked eye with an apparent visual magnitude of 7.41. The distance to this star, as determined by parallax measurements, is 219 light-years, and it is drifting further away with a radial velocity of +7.4 km/s. A 2015 survey ruled out the existence of any stellar companions at projected distances above 30 astronomical units.
HD 175167 is a star with an exoplanet companion in the southern constellation of Pavo. It is too faint to be visible with the naked eye at an apparent visual magnitude of 8.01. The system is located at a distance of 232 light-years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.190 arcsec yr−1.
HD 175167 b is an exoplanet orbiting HD 175167, which is a G type star within the Pavo constellation 232 light-years away from the Earth. The planet was discovered by the Magellan Planet Search Program as the astronomical object fit the Keplerian orbital model. During the observations 13 doppler velocity tests were conducted, which showed this object's mass was at least 7.8 Jovian-masses and its orbit has a high eccentricity. The exoplanet takes 3.53 years to complete a full stellar orbit.
HD 79498 is a double star in the northern constellation of Cancer. The primary component of this pair has an orbiting exoplanet companion. This star is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.05. The system is located at a distance of 159 light years based on parallax measurements, and is drifting further away with a heliocentric radial velocity of 20 km/s. It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.2″·yr−1.
HD 98649 is a star with an orbiting exoplanet in the southern Crater constellation. Based on parallax measurements, it is located at a distance of 137.5 light years from the Sun. The system is drifting further away with a heliocentric radial velocity of 4.3 km/s. With an apparent visual magnitude of +8.00, it is too faint to be viewed with the naked eye. The system has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.24″·yr−1.
HD 106515 is a binary star in the constellation of Virgo.
HD 7449 is a binary star system about 126 light-years way. The primary star, HD 7449 A, is a main-sequence star belonging to the spectral class F9.5. It is younger than the Sun. The primary star is slightly depleted of heavy elements, having 80% of solar abundance.
HD 203473 is a star in the equatorial constellation Equuleus. With an apparent magnitude of 8.23, it’s only visible by using an amateur telescope. The star is located at a distance of 237 light years based on its parallax shift but is drifting closer at a high rate of 61.7 km/s. As of 2014, no stellar companions have been detected around the star.