HR 8442

HR 8442
Observation data; Epoch J2000.0 Equinox ICRS
Constellation	Cepheus
Right ascension	22h 07m 09.634s
Declination	+58° 50′ 26.58″
Apparent magnitude (V)	6.32
Characteristics
Spectral type	G8.6 III
U−B color index	0.63
B−V color index	0.88
Astrometry
Radial velocity (Rv)	−7.37±0.03 km/s
Proper motion (μ)	RA: −16.09±0.41 mas/yr ; Dec.: −22.30±0.41 mas/yr
Parallax (π)	4.80±0.46 mas
Distance	680 ± 70 ly ; (210 ± 20 pc)
Absolute magnitude (MV)	−0.3±0.2
Orbit
Primary	HR 8442A
Secondary	HR 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 M☉
Radius	14.4 R☉
Luminosity	143 L☉
Surface gravity (log g)	3.21 cgs
Temperature	5261±40 K
Rotational velocity (v sin i)	1.8 km/s
Age	0.35 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.

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. Roger Griffin then placed the star on his observing program at Cambridge Observatory leading to an orbital solution being published in 2015.

References

↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
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
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.
↑ Gray, David F. (1989). "The rotational break for G giants". Astrophysical Journal. 347: 1021–1029. Bibcode:1989ApJ...347.1021G. doi:10.1086/168192.
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.
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.
1 2 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel; Jenkins, Jon M.; Stassun, Keivan; Twicken, Joseph D.; Vanderspek, Roland; Winn, Joshua N. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series. 268 (1): 4. arXiv:2208.11721. Bibcode:2023ApJS..268....4F. doi:10.3847/1538-4365/acdee5.
↑ Soubiran, C.; Brouillet, N.; Casamiquela, L. (2022). "Assessment of [Fe/H] determinations for FGK stars in spectroscopic surveys". Astronomy and Astrophysics. 663: A4. arXiv:2112.07545. Bibcode:2022A&A...663A...4S. doi:10.1051/0004-6361/202142409.
↑ De Medeiros, J. R.; Da Silva, J. R. P.; Maia, M. R. G. (2002). "The Rotation of Binary Systems with Evolved Components". The Astrophysical Journal. 578 (2): 943. arXiv:astro-ph/0207288. Bibcode:2002ApJ...578..943D. doi:10.1086/342613.
↑ 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.

[Roman1987-1] Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.

[van_Leeuwen2007-2] 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

[Argue1966-3] 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.

[Gray1989-4] Gray, David F. (1989). "The rotational break for G giants". Astrophysical Journal. 347: 1021–1029. Bibcode:1989ApJ...347.1021G. doi:10.1086/168192.

[Griffin2015-5] 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.

[Luck2015-6] 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.

[fetherolf2023-7] 1 2 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel; Jenkins, Jon M.; Stassun, Keivan; Twicken, Joseph D.; Vanderspek, Roland; Winn, Joshua N. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series. 268 (1): 4. arXiv:2208.11721. Bibcode:2023ApJS..268....4F. doi:10.3847/1538-4365/acdee5.

[soubiran2022-8] Soubiran, C.; Brouillet, N.; Casamiquela, L. (2022). "Assessment of [Fe/H] determinations for FGK stars in spectroscopic surveys". Astronomy and Astrophysics. 663: A4. arXiv:2112.07545. Bibcode:2022A&A...663A...4S. doi:10.1051/0004-6361/202142409.

[demedeiros2002-9] De Medeiros, J. R.; Da Silva, J. R. P.; Maia, M. R. G. (2002). "The Rotation of Binary Systems with Evolved Components". The Astrophysical Journal. 578 (2): 943. arXiv:astro-ph/0207288. Bibcode:2002ApJ...578..943D. doi:10.1086/342613.

[de_Medeiros1999-10] 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.