HD 208527
HD 208527 is a M1III red giant star located in Pegasus.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 21h 56m 23.98467s[1] |
| Declination | +21° 14′ 23.4961″[1] |
| Apparent magnitude (V) | +6.39 |
| Characteristics | |
| Spectral type | M1III[2][3] |
| Astrometry | |
| Radial velocity (Rv) | 4.79 ± 0.06[3] km/s |
| Proper motion (μ) | RA: 2.00[1] mas/yr Dec.: 15.30[1] mas/yr |
| Parallax (π) | 2.48 ± 0.38[1] mas |
| Distance | approx. 1,300 ly (approx. 400 pc) |
| Absolute magnitude (MV) | –1.24[3] |
| Details | |
| Mass | 1.6 ± 0.4[2] M☉ |
| Radius | 51.1 ± 8.3[2] R☉ |
| Surface gravity (log g) | 1.6 ± 0.3[3] cgs |
| Temperature | 4035 ± 65[3] K |
| Metallicity [Fe/H] | −0.09 ± 0.16[2] dex |
| Rotational velocity (v sin i) | 3.6[3] km/s |
| Age | 2 ± 1.3[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
It has been considered K5V, but is now known as M1III due to radius, as well as surface gravity.[3]
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.[2] Along with HD 220074 b this is one of the first two planets proposed around a red giant.
| 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 | — | — |
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References
- van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- "hd_208527_b".
- B.-C. Lee; I. Han; M.-G. Park (2012). "Planetary companions orbiting M giants HD 208527 and HD 220074". Astronomy & Astrophysics. 549: A2. arXiv:1211.2051. Bibcode:2013A&A...549A...2L. doi:10.1051/0004-6361/201220301.
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