| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Coma Berenices [1] |
| HD 115404 A | |
| Right ascension | 13h 16m 51.05143s [2] |
| Declination | +17° 01′ 01.8409″ [2] |
| Apparent magnitude (V) | 6.66 [3] |
| HD 115404 B | |
| Right ascension | 13h 16m 51.55401s [4] |
| Declination | +17° 00′ 59.8921″ [4] |
| Apparent magnitude (V) | 9.50 [3] |
| Characteristics | |
| HD 115404 A | |
| Evolutionary stage | main sequence [2] |
| Spectral type | K2 V [5] |
| U−B color index | +0.623 [6] |
| B−V color index | +0.917 [6] |
| HD 115404 B | |
| Evolutionary stage | main sequence [4] |
| Spectral type | M0.5 V [7] |
| B−V color index | +1.232 [8] |
| Astrometry | |
| HD 115404 A | |
| Radial velocity (Rv) | 7.62 ± 0.09 [9] km/s |
| Proper motion (μ) | RA: 636.285(28) mas/yr [2] Dec.: −264.678(31) mas/yr [2] |
| Parallax (π) | 91.0176±0.0236 mas [2] |
| Distance | 35.834 ± 0.009 ly (10.987 ± 0.003 pc) |
| Absolute magnitude (MV) | +6.3 [10] |
| HD 115404 B | |
| Radial velocity (Rv) | 5.95±0.13 [4] km/s |
| Proper motion (μ) | RA: 649.666(31) mas/yr [4] Dec.: −263.937(26) mas/yr [4] |
| Parallax (π) | 90.9475±0.0232 mas [4] |
| Distance | 35.862 ± 0.009 ly (10.995 ± 0.003 pc) |
| Absolute magnitude (MV) | 10.1 [10] |
| Orbit [11] | |
| 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 [12] M☉ |
| Radius | 0.76±0.02 [12] R☉ |
| Luminosity | 3.1 [12] L☉ |
| Surface gravity (log g) | 4.58±0.03 [12] cgs |
| Temperature | 4976 [12] K |
| Metallicity [Fe/H] | −0.08 [12] dex |
| Rotation | 18.2 days [13] |
| Rotational velocity (v sin i) | 2.8 [12] km/s |
| Age | 10.2 (5.4–13.5) [12] Gyr |
| HD 115404 B | |
| Mass | 0.542 [14] M☉ |
| Radius | 0.550 [14] R☉ |
| Luminosity | 0.043 [15] L☉ |
| Surface gravity (log g) | 4.90 [15] cgs |
| Temperature | 3,709 [16] K |
| Rotational velocity (v sin i) | 9.6 [15] km/s |
| Age | 3.0 [16] Gyr |
| Other designations | |
| BD+17°2611, GJ 505, HD 115404, HIP 64797, SAO 100491, LHS 2713 [17] | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
| 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. [18] The combined apparent magnitude of the system is 6.52, [17] with the magnitudes of the components being 6.66 and 9.50. [3]
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. [12] Its companion is a red dwarf (M0.5 V). [7] It has 54.2% the mass of the Sun, and is 0.55 times as wide. [14] The two stars orbit each other every 770 years, and are separated by about 8″. [11] The system is thought to be fairly old, at 5.4 to 13.5 billion years old. [12]
In 2022, two exoplanets, Neptunian and super-Jovian in mass, were reported in orbit around the primary star using a combination of radial velocity and astrometry. [19] However, a 2025 study using radial velocity observations failed to detect these planets. [20]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b(disputed [20] ) | ≥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(disputed [20] ) | 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 ° | — |