| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 18h 32m 15.4933s [1] |
| Declination | 06° 56′ 44.6858″ [1] |
| Apparent magnitude (V) | 8.301 [2] |
| Characteristics | |
| Spectral type | G0 [3] |
| B−V color index | 0.61 [3] |
| Astrometry | |
| Radial velocity (Rv) | +13.48±0.28 [1] km/s |
| Proper motion (μ) | RA: −42.869±0.084 [1] mas/yr Dec.: −14.705±0.077 [1] mas/yr |
| Parallax (π) | 8.9274 ± 0.0497 mas [1] |
| Distance | 365 ± 2 ly (112.0 ± 0.6 pc) |
| Details | |
| Mass | 1.01±0.06 [2] M☉ |
| Radius | 2.42+0.01 −0.03 [1] R☉ |
| Luminosity | 5.406+0.042 −0.041 [1] L☉ |
| Surface gravity (log g) | 3.84±0.03 [2] cgs |
| Temperature | 5,671±16 [2] K |
| Metallicity [Fe/H] | −0.48±0.01 [2] dex |
| Rotational velocity (v sin i) | 2.3 [3] km/s |
| Age | 4.890±0.229 [4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 171028 is a star with an exoplanet companion in the equatorial constellation of Ophiuchus. With an apparent visual magnitude of 8.3, [2] it is too faint to be readily visible with the naked eye. Unlike most planet-harboring stars, it does not have a Hipparcos number. The star is located at a distance of approximately 365 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +13.5 km/s. [1]
This is a yellow-hued G-type star of unknown luminosity class with a stellar classification of G0. [3] It is a metal-poor star belonging to the thin disk population. [6] HD 171028 is estimated to be nearly five billion years old and is spinning with a projected rotational velocity of 2.3 km/s. [3] It has the same mass as the Sun, but the radius is 2.4 times larger. The star is radiating 5.4 [1] times the luminosity of the Sun from its photosphere at an effective temperature of 5,671 K. [2]
In the summer of 2007, a Jovian planetary companion was discovered by the HARPS planet search program using the radial velocity method. [3] This object is orbiting at a distance of 1.32 AU from the host star with a period of 1.5 years and an eccentricity (ovalness) of 0.59. Since the inclination of the orbit is unknown, only a minimum mass can be determined. This planet has at least double the mass of Jupiter. [7]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.98 MJ | 1.32 | 550±3 | 0.59±0.01 | — | — |
HD 4308 is a single star in the southern constellation of Tucana. It has a yellow hue and is a challenge to view with the naked eye even under good seeing conditions, having an apparent visual magnitude of 6.54. This object is located at a distance of 72 light years, as determined from parallax measurements. It is a population II star and is considered to be a member of the thick disk. The star is receding from the Sun with a radial velocity of +95 km/s.
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 190647 is a yellow-hued star with an exoplanetary companion, located in the southern constellation of Sagittarius. It has an apparent visual magnitude of 7.78, making this an 8th magnitude star that is much too faint to be readily visible to the naked eye. The star is located at a distance of 178 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −40 km/s. It is also called HIP 99115.
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 47186 is a star located approximately 129 light-years away in the constellation of Canis Major. It is a G6V star with the characteristics very similar to the Sun, but it is 1.7 times more metal-rich. In 2008, two extrasolar planets were discovered orbiting the star.
HD 131664 is an 8th magnitude star in the southern constellation of Apus with an orbiting brown dwarf or stellar companion. Parallax measurements by the Gaia space observatory provide an estimated distance of 172.5 light years from the Earth. The system is moving further away with a baseline heliocentric radial velocity of +35 km/s.
HD 45364 is a star in the southern constellation of Canis Major. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 8.08. The distance to this system is 112 light years based on parallax. It is drifting further away from the Sun with a radial velocity of +16.4 km/s, having come within 49 light-years some 1.5 million years ago.
HD 5388 is a single star in the southern constellation of Phoenix. It has the Gould designation 78 G. Phoenicis, while HD 5388 is the star's Henry Draper Catalogue identifier. This object has a yellow-white hue and is too faint to be readily visible to average human eyesight, having an apparent visual magnitude of 6.73. It is located at a separation of 173 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +39 km/s.
HD 181720 is an 8th-magnitude G-type main sequence star located approximately 190 light-years away in the constellation Sagittarius. This star is larger, hotter, brighter and less massive than the Sun. Also its metal content is three-tenths as much as the Sun.
HD 190984, also known as HIP 99496, is a star located in the southern circumpolar constellation Pavo, the peacock. It has an apparent magnitude of 8.76, making it readily visible in small telescopes, but not to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 486 light years away from the Solar System. It appears to be receding with a heliocentric radial velocity of 20.3 km/s.
HD 215497 is a single star in the southern constellation of Tucana. It has an orange hue with an apparent visual magnitude of 8.96, which is too dim to be viewed with the naked eye. A 2015 survey ruled out the existence of any stellar companions at projected distances from 26 to 300 astronomical units. Based on parallax measurements, it is located at a distance of 132 light years from the Sun. The star is drifting further away with a radial velocity of +49 km/s, having come as close as 45 light-years some 774,000 years ago. The absolute magnitude of this star is 5.77.
HD 85390 is a star with an exoplanet companion in the southern constellation of Vela. It was given the proper name Natasha by Zambia during the 100th anniversary of the IAU. Natasha means "thank you" in many languages of Zambia. This star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.54. It is located at a distance of 109 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 33 km/s.
HD 103197 is a star with a planetary companion in the southern constellation of Centaurus. It has an apparent visual magnitude of 9.40, which is too faint to be viewed with the naked eye. Based on parallax measurements, HD 103197 is located at a distance of 187 light years from the Sun. It is drifting closer with a radial velocity of −4.6 km/s.
HD 104067 is a star with a planetary companion in the southern constellation of Corvus. It has an apparent visual magnitude of 7.92 which is too faint to be visible with the naked eye. The distance to this star is 66 light years based on parallax. It is drifting further away with a radial velocity of +15 km/s.
HIP 70849 is a star with two non-stellar companions in the southern constellation Lupus. It is a 10th magnitude star, making it too faint to be visible to the naked eye. The system is located at a distance of 78.7 light-years from the Sun based on parallax measurements.
HD 113538 is a star with two planetary companions in the southern constellation of Centaurus. It is much too faint to be viewed with the naked eye at an apparent visual magnitude of 9.05. The distance to this star is 53 light years and it is drifting further away with a radial velocity of +39 km/s.
HD 106515 is a binary star in the constellation of Virgo.
HD 109271 is a star in the constellation of Virgo. With an apparent magnitude of 8.05, it cannot be seen with the naked eye. Parallax measurements made by Gaia put the star at a distance of 182 light-years away.
HD 7199 is a star in the constellation Tucana located 118 light years distance from the Sun based on parallax. It has an orange hue but is too dim to be viewed with the naked eye, having an apparent visual magnitude of +8.06. The star is drifting further away from the Sun with a radial velocity of +5.6 km/s.
HD 96700 is the Henry Draper Catalogue designation for a star in the equatorial constellation of Hydra. It has an apparent visual magnitude of 6.51, which puts it below the limit that can be seen with the naked eye by a typical observer. Based upon parallax measurements, this star is around 83 light years away from the Sun. It is drifting further away with a radial velocity of 12.8 km/s.