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] |
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 | |
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]
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 ° |
— |
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] |
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 | |
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]
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 ° |
— |