HD 115404

HD 115404 is a binary star system located in the constellation Coma Berenices. Parallax measurements made by Hipparcos put the system at 36 light-years, or 11 parsecs, away.[7] The combined apparent magnitude of the system is 6.52,[11] with the magnitudes of the components being 6.66 and 9.50.[1]

HD 115404

Observation data Epoch 2000      Equinox 2000
Constellation	Coma Berenices
HD 115404 A
Right ascension	13^h 16^m 51.048^s[1]
Declination	+17° 01′ 01.94″[1]
Apparent magnitude (V)	6.66[1]
HD 115404 B
Right ascension	13^h 16^m 51.0540^s[2]
Declination	+17° 01′ 01.829″[2]
Apparent magnitude (V)	9.50[1]
Characteristics
U−B color index	+0.64[3]
B−V color index	+0.92[3]
HD 115404 A
Spectral type	K2 V[4]
HD 115404 B
Spectral type	M0.5 V[5]
Astrometry
Radial velocity (Rv)	7.62 ± 0.09[6] km/s
Proper motion (μ)	RA: 632.60[7] mas/yr Dec.: −262.21[7] mas/yr
Parallax (π)	90.32 ± 0.74[7] mas
Distance	36.1 ± 0.3 ly (11.07 ± 0.09 pc)
Orbit[8]
Period (P)	770.0 yr
Semi-major axis (a)	8.06″
Eccentricity (e)	0.12
Inclination (i)	93.41°
Longitude of the node (Ω)	104.66°
Periastron epoch (T)	B 1875.0
Argument of periastron (ω) (secondary)	276.99°
Details
HD 115404 A
Mass	0.70 ± 0.09[9] M☉
Radius	0.76 ± 0.02[9] R☉
Luminosity	3.1[9] L☉
Surface gravity (log g)	4.58 ± 0.03[9] cgs
Temperature	4976[9] K
Metallicity [Fe/H]	−0.08[9] dex
Rotational velocity (v sin i)	2.8[9] km/s
Age	10.2 (5.4–13.5)[9] Gyr
HD 115404 B
Mass	0.542[10] M☉
Radius	0.550[10] R☉
Other designations
BD+17° 2611, GJ 505, HD 115404, HIP 64797, SAO 100491, LHS 2713[11]
Database references
SIMBAD	AB
ARICNS	A
	B

The primary component, designated A, is a K-type main sequence star.[4] It is about 70% as massive as the Sun, and is 0.76 times as wide.[9] Its companion is a red dwarf (M0.5 V).[5] It has 54.2% the mass of the Sun, and is 0.55 times as wide.[10] The two stars orbit each other every 770 years, and are separated by about 8″.[8] The system is thought to be fairly old, at 5.4 to 13.5 billion years old.[9]

References

1. Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics. 384: 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
2. Gaia Collaboration (2016). "Gaia Data Release 1". Astronomy & Astrophysics. 595: A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512.
3. Cowley, A. P.; Hiltner, W. A.; Witt, A. N. (1967). "Spectral classification and photometry of high proper motion stars". The Astronomical Journal. 72: 1334. Bibcode:1967AJ.....72.1334C. doi:10.1086/110413.
4. White, Russel J.; Gabor, Jared M.; Hillenbrand, Lynne A. (2007). "High-Dispersion Optical Spectra of Nearby Stars Younger Than the Sun". The Astronomical Journal. 133 (6): 2524. arXiv:0706.0542. Bibcode:2007AJ....133.2524W. doi:10.1086/514336.
5. Alonso-Floriano, F. J.; et al. (2015). "CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS" (PDF). Astronomy & Astrophysics. 577: A128. arXiv:1502.07580. Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803.
6. Maldonado, J.; Martínez-Arnáiz, R. M.; Eiroa, C.; Montes, D.; Montesinos, B. (2010). "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups". Astronomy and Astrophysics. 521: A12. arXiv:1007.1132. Bibcode:2010A&A...521A..12M. doi:10.1051/0004-6361/201014948.
7. 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
8. "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Retrieved 11 August 2017.
9. Brewer, John M.; Fischer, Debra A.; Valenti, Jeff A.; Piskunov, Nikolai (2016). "Spectral Properties of Cool Stars: Extended Abundance Analysis of 1,617 Planet-Search Stars". The Astrophysical Journal Supplement Series. 225 (2): 32. arXiv:1606.07929. Bibcode:2016ApJS..225...32B. doi:10.3847/0067-0049/225/2/32.
10. Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry; Calkins, Michael L.; Mink, Jessica (2017). "The Hα emission of nearby M dwarfs and its relation to stellar rotation". The Astrophysical Journal. 834: 85. arXiv:1611.03509. Bibcode:2017ApJ...834...85N. doi:10.3847/1538-4357/834/1/85.
11. "HD 115404". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 August 2017.