HD 7924

HD 7924

Position of star HD 7924 in the constellation Cassiopeia
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia
Right ascension 01h 21m 59.11s[1]
Declination +76° 42′ 37.0″[1]
Apparent magnitude (V) 7.185
Characteristics
Spectral type K0V
Apparent magnitude (B) 8.005
Apparent magnitude (J) 5.618
Apparent magnitude (H) 5.231
Apparent magnitude (K) 5.159
B−V color index 0.820
Variable type none
Astrometry
Radial velocity (Rv)–22.7 km/s
Proper motion (μ) RA: –34.23 ± 0.43[1] mas/yr
Dec.: –33.28 ± 0.48[1] mas/yr
Parallax (π)59.49 ± 0.46[1] mas
Distance54.8 ± 0.4 ly
(16.8 ± 0.1 pc)
Absolute magnitude (MV)6.056
Details
Mass0.81 ± 0.01[2] M☉
Radius0.74 ± 0.01[2] R☉
Luminosity0.364 ± 0.001[2] L☉
Surface gravity (log g)4.6 ± 0.01[2] cgs
Temperature5216 ± 13[2] K
Metallicity-0.15 ± 0.03
Age3.0 ± 1.8[2] Gyr
Other designations
BD+75°58, GCRV 766, Gliese 56.5, GSC 04494-01396, HIP 6379, 2MASS J01215911+7642372, PPM 4675, SAO 4386, TYC 4494-1346-1, Wo 9054
Database references
SIMBADdata
Exoplanet Archivedata
ARICNSdata
Extrasolar Planets
Encyclopaedia		data

HD 7924 is a 7th magnitude K-type main sequence star located approximately 55 light years away in the constellation Cassiopeia. This star is smaller, cooler, dimmer, and less massive than our Sun. Also its metal content is about seven-tenths as much as the Sun. In 2009, a super-Earth exoplanet was found in orbit around the star.[3] In 2015, two more planets were discovered, and the mass of the original planet was revised downwards slightly.[4][5]

The HD 7924 planetary system[3][5]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥8.68 ± 0.52 M⊕ 0.05664 ± 0.00068 5.39792 ± 0.00025 0.058 +0.056
−0.040		 — —
c ≥7.86 ± 0.72 M⊕ 0.1134 ± 0.0014 15.299 ± 0.0033 0.098 +0.096
−0.069		 — —
d ≥6.44 ± 0.79 M⊕ 0.1551 ± 0.0019 24.451 ± 0.016 0.21 +0.13
−0.12		 — —

See also

References

  1. 1 2 3 4 5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. 1 2 3 4 5 6 Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302Freely accessible. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
  3. 1 2 Howard, Andrew W.; et al. (2009). "The NASA-UC Eta-Earth Program. I. A Super-Earth Orbiting HD 7924". The Astrophysical Journal. 696 (1): 75–83. arXiv:0901.4394Freely accessible. Bibcode:2009ApJ...696...75H. doi:10.1088/0004-637X/696/1/75.
  4. ↑ http://newscenter.berkeley.edu/2015/04/28/robotic-telescope-discovers-three-super-earth-planetary-neighbors/
  5. 1 2 http://arxiv.org/abs/1504.06629

Coordinates: 01h 21m 59.1153s, +76° 42′ 37.024″


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