HD 219828

HD 219828
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pegasus
Right ascension 23h 18m 46.734156s[1]
Declination +18° 38′ 44.619358″[1]
Apparent magnitude (V) 8.04[2]
Characteristics
Spectral type G0IV[2]
B−V color index 0.654[2]
Astrometry
Radial velocity (Rv)−24.07±0.12[1] km/s
Proper motion (μ) RA: −5.010±0.028 mas/yr[1]
Dec.: 5.758±0.022 mas/yr[1]
Parallax (π)13.7872 ± 0.0278 mas[1]
Distance236.6 ± 0.5 ly
(72.5 ± 0.1 pc)
Absolute magnitude (MV)3.58[2]
Details[2]
Mass1.23±0.10 M
Radius1.69 R
Luminosity3.08 L
Surface gravity (log g)4.08±0.10 cgs
Temperature5,891±18 K
Metallicity [Fe/H]+0.19±0.03 dex
Rotational velocity (v sin i)2.9 km/s
Age4.6±0.7 Gyr
Other designations
BD17 4896, HIP 115100, SAO 108536, GSC 01716-01182[3]
Database references
SIMBADdata

HD 219828 is a star with two exoplanetary companions in the constellation of Pegasus. With an apparent visual magnitude of 8.04,[2] it is an eighth magnitude star that is too dim to be readily visible to the naked eye. The star is located at a distance of approximately 237 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −24 km/s.[1]

The stellar classification of this star is G0IV, matching a subgiant star that is ending the hydrogen fusion in its core. It is a metal-rich star that has slightly evolved off the main sequence. HD 219828 is older than two billion years with a low level of chromospheric activity and is spinning with a projected rotational velocity of 2.9 km/s. It has 1.23 times the mass of the Sun with radius estimates ranging from 1.47 to 1.69 the Sun's girth. The star is radiating three times the luminosity of the Sun from its slightly enlarged photosphere at an effective temperature of 5,891 K.[2]

  1. ^ a b c d e f Cite error: The named reference Gaia DR3 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference Santos_et_al_2016 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Simbad was invoked but never defined (see the help page).