HR 8442

Last updated
HR 8442
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Cepheus
Right ascension 22h 07m 09.634s [1]
Declination +58° 50 26.58 [1]
Apparent magnitude  (V)6.32 [2]
Characteristics
Spectral type G8.6 III [3]
U−B color index 0.63 [2]
B−V color index 0.88 [2]
Astrometry
Radial velocity (Rv)−7.37±0.03 [4]  km/s
Proper motion (μ)RA: −16.09±0.41 [1]   mas/yr
Dec.: −22.30±0.41 [1]   mas/yr
Parallax (π)4.80 ± 0.46  mas [1]
Distance 680 ± 70  ly
(210 ± 20  pc)
Absolute magnitude  (MV)−0.3±0.2 [4]
Orbit [4]
PrimaryHR 8442A
CompanionHR 8442B
Period (P)737.4±0.4 days
Eccentricity (e)0.308±0.007
Periastron epoch (T)54113.3±2.1
Argument of periastron (ω)
(secondary)
61.9±1.3°
Semi-amplitude (K1)
(primary)
5.55±0.04 km/s
Details
Mass 2.97 [5]   M
Temperature 5261±40 [5]   K
Age 0.35 [5]   Gyr
Other designations
BD+58 2393, FK5  3770, HD  210220, HIP  109190, HR  8442, SAO  34072
Database references
SIMBAD data

HR 8442 is a spectroscopic binary star in the constellation Cepheus. The primary is a G type giant star while the secondary's spectral type is unknown. [4]

The spectroscopic binary nature of the star was first noticed by Jose Renan de Medeiros and Michel Mayor using radial velocity measurements from the Coravel spectrometer at Haute-Provence Observatory. [6] Roger Griffin then placed the star on his observing program at Cambridge Observatory leading to an orbital solution being published in 2015. [4]

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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: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600. Vizier catalog entry
  2. 1 2 3 Argue, A. N. (1966). "UBV photometry of 550 F, G and K type stars". Monthly Notices of the Royal Astronomical Society. 133 (4): 175–493. Bibcode:1966MNRAS.133..475A. doi: 10.1093/mnras/133.4.475 .
  3. Gray, David F. (1989). "The rotational break for G giants". Astrophysical Journal. 347: 1021–1029. Bibcode:1989ApJ...347.1021G. doi: 10.1086/168192 .
  4. 1 2 3 4 5 Griffin, R. F. (2015). "Spectroscopic binary orbits from photoelectric radial velocities. Paper 241: HR 1884, HD 174103, HD 182563, and HR 8442, with a note on zeta Cephei". The Observatory. 135: 71–95. Bibcode:2015Obs...135...71G.
  5. 1 2 3 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal. 150 (3). 88. arXiv: 1507.01466 . Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. S2CID   118505114.
  6. de Medeiros, J. R.; Mayor, M. (1999). "A catalog of rotational and radial velocities for evolved stars". Astronomy and Astrophysics Supplement. 139 (3): 433–460. arXiv: astro-ph/0608248 . Bibcode:1999A&AS..139..433D. doi:10.1051/aas:1999401.