HD 115404

HD 115404
Observation data
Epoch J2000      Equinox J2000
Constellation Coma Berenices
HD 115404 A
Right ascension 13h 16m 51.051430s[1]
Declination +17° 01′ 01.840901″[1]
Apparent magnitude (V) 6.66[2]
HD 115404 B
Right ascension 13h 16m 51.554014s[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]
Distance35.834 ± 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]
Distance35.862 ± 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
Mass0.70 ± 0.09[9] M☉
Radius0.76 ± 0.02[9] R☉
Luminosity3.1[9] L☉
Surface gravity (log g)4.58 ± 0.03[9] cgs
Temperature4976[9] K
Metallicity [Fe/H]−0.08[9] dex
Rotational velocity (v sin i)2.8[9] km/s
Age10.2 (5.4–13.5)[9] Gyr
HD 115404 B
Mass0.542[10] M☉
Radius0.550[10] R☉
Other designations
BD+17° 2611, GJ 505, HD 115404, HIP 64797, SAO 100491, LHS 2713[11]
Database references
SIMBADA
B
ARICNSA
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° 		—
  1. ^ a b c d Cite error: The named reference GaiaDR3A was invoked but never defined (see the help page).
  2. ^ a b c 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. ^ a b c d e Cite error: The named reference GaiaDR3B was invoked but never defined (see the help page).
  4. ^ a b 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. ^ a b 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. ^ a b 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. ^ a b "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. ^ a b c d e f g h i j 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. ^ a b c 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. ^ a b "HD 115404". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 11 August 2017.
  12. ^ Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Feng2022 was invoked but never defined (see the help page).