HD 171028

HD 171028
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]
Distance365 ± 2 ly
(112.0 ± 0.6 pc)
Details
Mass1.01±0.06[2] M
Radius2.42+0.01
−0.03
[1] R
Luminosity5.406+0.042
−0.041
[1] L
Surface gravity (log g)3.84±0.03[2] cgs
Temperature5,671±16[2] K
Metallicity [Fe/H]−0.48±0.01[2] dex
Rotational velocity (v sin i)2.3[3] km/s
Age4.890±0.229[4] Gyr
Other designations
BD+06 3833, TYC 458-1450-1, 2MASS J18321548+0656446[5]
Database references
SIMBADdata

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]

The HD 171028 planetary system[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
  1. ^ a b c d e f g h i j Cite error: The named reference Gaia DR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Sousa_et_al_2011 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Santos2007 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Costa_Silva_et_al_2020 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Haywood2008 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Santos2011 was invoked but never defined (see the help page).