HD 20781

HD 20781
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Fornax[1]
Right ascension 03h 20m 02.94286s[2]
Declination −28° 47′ 01.7905″[2]
Apparent magnitude (V) 8.48[3]
Characteristics
Spectral type K0V[3]
B−V color index 0.82[3]
Astrometry
Radial velocity (Rv)40.27±0.12[2] km/s
Proper motion (μ) RA: 348.869±0.015 mas/yr[2]
Dec.: −66.614±0.019 mas/yr[2]
Parallax (π)27.8123 ± 0.0239 mas[2]
Distance117.3 ± 0.1 ly
(35.96 ± 0.03 pc)
Absolute magnitude (MV)5.70[3]
Details[3]
Mass0.7 M
Luminosity0.49±0.04 L
Surface gravity (log g)4.37±0.05 cgs
Temperature5256±29 K
Metallicity [Fe/H]−0.11±0.02 dex
Rotation46.8±4.4 d
Rotational velocity (v sin i)1.1 km/s
Other designations
CD–29° 1229, HIP 15526, LTT 1581, SAO 168468, 2MASS J03200291-2847016, Gaia DR1 5060105892897388288[4]
Database references
SIMBADdata

HD 20781 is a star which is part of a wide binary system with HD 20782. The companion star has a very large angular separation of 252 arcsec, corresponding to 9080 AU at the distance of HD 20782.[5] Both stars possess their own planetary systems in S type orbits, with a total of five known planets around both stars.[3][6] This is the first known example of planets being found orbiting both components of a wide binary system.[5][7] HD 20781 has no noticeable starspot activity.[3]

  1. ^ Cite error: The named reference Roman1987 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b c d e f g Cite error: The named reference Udry2017 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Desidera was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference NASAExoplanetArchive was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Mayor2011 was invoked but never defined (see the help page).