HD 208527

HD 208527

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Pegasus
Right ascension	21^h 56^m 23.98^s[1]
Declination	+21° 14′ 23.4″[1]
Apparent magnitude (V)	+6.39
Characteristics
Spectral type	M1III[1][2]
Astrometry
Radial velocity (Rv)	4.79 ± 0.06[2] km/s
Proper motion (μ)	RA: ? mas/yr Dec.: ? mas/yr
Parallax (π)	2.48 ± 0.38[2] ± ? mas
Distance	1,044 ± 199 ly (320.2 ± 61.1[1] pc)
Absolute magnitude (MV)	–1.24[2]
Details
Mass	1.6 ± 0.4 [1] M☉
Radius	51.1 ± 8.3[1] R☉
Luminosity	? L☉
Surface gravity (log g)	1.6 ± 0.3[2] cgs
Temperature	4035 ± 65[2] K
Metallicity	-0.09 ± 0.16[1]
Rotation	51.1 ± 8.3[2]
Age	2 ± 1.3 × 10^9[1] years
Other designations
HD 208527, HIP 108296, HR 8372
Database references
SIMBAD	data
Exoplanet Archive	data
Extrasolar Planets Encyclopaedia	data

HD 208527 is a M1III red giant star located in Pegasus.

It has been considered K5V but is now known as M1III due to radius and surface gravity.^[2]

Planetary system

From September 2008 to June 2012, the team B.-C. Lee, I. Han, and M.-G. Park observed HD 208527 with "the high-resolution spectroscopy of the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) at Bohyunsan Optical Astronomy Observatory (BOAO)".

In 2012, a long-period, wide-orbiting planet was deduced by radial velocity. This was published in November, gaining the designation HD 208527 b.^[1] Along with HD 220074 b this is one of the first two planets proposed around a red giant.

The HD 208527 planetary system^[1]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	>9.9 ± 1.7 MJ	2.1 ± 0.2	875.5 ± 5.8	0.08 ± 0.04	—	—

References

1. "hd_208527_b".
2. B.-C. Lee, I. Han, M.-G. Park (2012). "Planetary companions orbiting M giants HD 208527 and HD 220074". Astronomy & Astrophysics. arXiv:1211.2051. Bibcode:2013A&A...549A...2L. doi:10.1051/0004-6361/201220301.