HD 220074

HD 220074 is a M2III red giant star located in Cassiopeia.

HD 220074
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Right ascension  23h 20m 14.380s[1]
Declination +61° 58′ 12.46″[1]
Apparent magnitude (V) +6.39
Characteristics
Spectral type M2III[2][3]
Astrometry
Radial velocity (Rv)–36.89 ± 0.21[2] km/s
Proper motion (μ) RA: 7.68 ± 0.44[1] mas/yr
Dec.: –5.43 ± 0.41[1] mas/yr
Parallax (π)3.08 ± 0.43[1] mas
Distanceapprox. 1,100 ly
(approx. 320 pc)
Absolute magnitude (MV)– 1.52[2]
Details
Mass1.2 ± 0.3[3] M☉
Radius49.7 ± 9.5[3] R☉
Luminosity? L☉
Surface gravity (log g)1.3 ± 0.5[2] cgs
Temperature3935 ± 110[2] K
Metallicity–0.25 ± 0.25[3]
Rotation3.0[2]
Age4.5 ± 2.8 × 109[3] years
Other designations
BD+61° 2427, HD 220074, HIP 115218, HR 8881, SAO 20567
Database references
SIMBADdata
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia		data

It had been considered K1V but is now known as M2III 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 220074 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 eccentric planet was deduced by radial velocity. This was published in November, gaining the designation HD 220074 b.[3] Along with HD 208527 b this is one of the first two planets proposed around a red giant.

The HD 220074 planetary system[3]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b >11.1 ± 1.8 MJ 1.6 ± 0.1 672.1 ± 3.7 0.14 ± 0.05 — —

References
  1. 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.Vizier catalog entry
  2. B.-C. Lee, I. Han, M.-G. Park (2012). "Planetary companions orbiting M giants HD208527 and HD 220074". Astronomy & Astrophysics. arXiv:1211.2051. Bibcode:2013A&A...549A...2L. doi:10.1051/0004-6361/201220301.CS1 maint: uses authors parameter (link)
  3. "hd_220074_b".
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.