HD 208527

HD 208527
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pegasus
Right ascension 21h 56m 23.984s[1]
Declination +21° 14′ 23.49″[1]
Apparent magnitude (V) +6.39[2]
Characteristics
Spectral type M1III[3]
B−V color index 1.698±0.002[2]
Astrometry
Radial velocity (Rv)+4.79±0.06[3] km/s
Proper motion (μ) RA: 1.433 mas/yr[1]
Dec.: 14.675 mas/yr[1]
Parallax (π)3.0302 ± 0.049 mas[1]
Distance1,080 ± 20 ly
(330 ± 5 pc)
Absolute magnitude (MV)–1.24[3]
Details[3]
Mass1.6±0.4 M
Radius57.6±6.5[4] R
Luminosity729±30[4] L
Surface gravity (log g)1.6±0.3 cgs
Temperature4,035±65 K
Metallicity [Fe/H]−0.09±0.16 dex
Rotational velocity (v sin i)3.6 km/s
Age2±1.3 Gyr
Other designations
BD+20° 5046, GJ 841.1, HD 208527, HIP 108296, HR 8372, SAO 90112[5]
Database references
SIMBADdata
Exoplanet Archivedata

HD 208527 is a star with an orbiting exoplanet located in the northern constellation of Pegasus. It has a reddish hue and is dimly visible to the naked eye with an apparent visual magnitude of +6.39.[2] The star is located at a distance of approximately 1,080 light years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +4.8 km/s.[3] It is currently the largest star known to have an exoplanet.

This was once catalogued as a K-type main-sequence star with a stellar classification of K5V, but is now known as an aging red giant with a class of M1III, based on its dimensions and low surface gravity.[3] This indicates that the two-billion year old star has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. It has an estimated 1.6[3] times the mass of the Sun but has swollen to 58 times the Sun's radius. The star is radiating 729[4] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,035 K.[3]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference Anderson_Francis_2012 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Lee was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Johns_et_al_2018 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).