HD 115404

HD 115404

Observation data Epoch J2000      Equinox J2000
Constellation	Coma Berenices
HD 115404 A
Right ascension	13^h 16^m 51.051430^s[1]
Declination	+17° 01′ 01.840901″[1]
Apparent magnitude (V)	6.66[2]
HD 115404 B
Right ascension	13^h 16^m 51.554014^s[3]
Declination	+17° 00′ 59.892133″[3]
Apparent magnitude (V)	9.50[2]
Characteristics
U−B color index	+0.64[4]
B−V color index	+0.92[4]
HD 115404 A
Spectral type	K2 V[5]
HD 115404 B
Spectral type	M0.5 V[6]
Astrometry
HD 115404 A
Radial velocity (Rv)	7.62 ± 0.09[7] km/s
Proper motion (μ)	RA: 636.285±0.028 mas/yr[1] Dec.: −264.678±0.031 mas/yr[1]
Parallax (π)	91.0176 ± 0.0236 mas[1]
Distance	35.834 ± 0.009 ly (10.987 ± 0.003 pc)
HD 115404 B
Radial velocity (Rv)	5.95±0.13[3] km/s
Proper motion (μ)	RA: 649.666±0.031 mas/yr[3] Dec.: −263.937±0.026 mas/yr[3]
Parallax (π)	90.9475 ± 0.0232 mas[3]
Distance	35.862 ± 0.009 ly (10.995 ± 0.003 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	A
	B
ARICNS	A
	B

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.[12] The combined apparent magnitude of the system is 6.52,[11] with the magnitudes of the components being 6.66 and 9.50.[2]

The primary component, designated A, is a K-type main sequence star.[5] 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).[6] 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]

In 2022, two exoplanets, Neptunian and super-Jovian in mass, were discovered in orbit around the primary star using a combination of radial velocity and astrometry.[13]

The HD 115404 A planetary system[13]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥0.097+0.020 −0.022 MJ	0.088+0.003 −0.004	10.5+0.001 −0.002	0.232+0.197 −0.138	—	—
c	10.319+1.473 −1.209 MJ	11.364+3.301 −1.905	15319.2+7240.3 −3526.2	0.211+0.173 −0.102	25.791+1.842 −2.157°	—

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. 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.
3. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
4. 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.
5. 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. S2CID 122854.
6. Alonso-Floriano, F. J.; Morales, J. C.; Caballero, J. A.; Montes, D.; Klutsch, A.; Mundt, R.; Cortés-Contreras, M.; Ribas, I.; Reiners, Ansgar; Amado, P. J.; Quirrenbach, A.; Jeffers, S. V. (2015). "CARMENES input catalogue of M dwarfs" (PDF). Astronomy & Astrophysics. 577: A128. arXiv:1502.07580. Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803. S2CID 53135130.^[permanent dead link‍]
7. 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. S2CID 119209183.
8. "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. 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. S2CID 118507965.
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 (1): 85. arXiv:1611.03509. Bibcode:2017ApJ...834...85N. doi:10.3847/1538-4357/834/1/85. S2CID 55000202.
11. "HD 115404". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 August 2017.
12. 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
13. Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.