HD 220074

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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
LuminosityL
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

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

It had been considered K1V but is now known as M2III due to radius and surface gravity.[2]

Planetary system[edit]

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[edit]

  1. ^ a b c d e 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. ^ a b c d e f g 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.
  3. ^ a b c d e f g "hd_220074_b".