HD 114762
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Coma Berenices |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 7.30[2] + 15.00[3] |
| Characteristics | |
| A | |
| Evolutionary stage | Main sequence |
| Spectral type | F9V[4] |
| B−V Template:Engvar | 0.525[2] |
| B | |
| Evolutionary stage | Main sequence |
| Spectral type | sdM9[5] |
| J−K Template:Engvar | 0.70 |
| Astrometry | |
| Radial velocity (Rv) | Script error: No such module "val".[1] km/s |
| Proper motion (μ) | RA: −580.999 mas/yr[1] Dec.: 1.062 mas/yr[1] |
| Parallax (π) | 26.1979±0.1082 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Orbit[6] | |
| Companion | HD 114762 Ab |
| Period (P) | Script error: No such module "val". |
| Semi-major axis (a) | Script error: No such module "val".[7] |
| Eccentricity (e) | Script error: No such module "val". |
| Inclination (i) | Script error: No such module "val".° |
| Periastron epoch (T) | Script error: No such module "val". |
| Argument of periastron (ω) (primary) | Script error: No such module "val".[7]° |
| Semi-amplitude (K1) (primary) | Script error: No such module "val". km/s |
| Details | |
| HD 114762 A | |
| Mass | Script error: No such module "val".[6] Template:Solar mass |
| Radius | Script error: No such module "val".[2] Template:Solar radius |
| Surface gravity (log g) | Script error: No such module "val".[4] cgs |
| Temperature | Script error: No such module "val".[4] K |
| Metallicity [Fe/H] | Script error: No such module "val".[4] dex |
| Age | Script error: No such module "val".[4] Gyr |
| HD 114762 Ab | |
| Mass | Script error: No such module "val".[6] Template:Solar mass |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| HD 114762 B | |
| Mass | 0.0879[5] Template:Solar mass |
| Radius | 0.100[5] Template:Solar radius |
| Luminosity | 0.00043[5] Template:Solar luminosity |
| Surface gravity (log g) | 5.381[5] cgs |
| Temperature | 2,645[5] K |
| Metallicity [Fe/H] | −0.71[5] dex |
| Age | ~10[5] Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist[8] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
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HD 114762 is a triple star system[3][4] approximately Script error: No such module "convert". away in the constellation Coma Berenices. It consists of a yellow-white F-type main-sequence star (HD 114762 A) and two red dwarf companions (HD 114762 Ab & HD 114762 B) approximately 0.36 & 130 AU distant.[3][4] Both are low-metal subdwarfs. Planets around such metal-poor stars are rare (three known cases are HD 22781, HD 111232, and HD 181720).[9] A telescope or strong binoculars are needed to view the primary. HD 114762 had been used by scientists as a "standard star", one whose radial velocity is well established, but with the discovery of the spectroscopic companion HD 114762 Ab its usefulness as a standard has been called into question.[10]
The red dwarf companion is classified as an ultra-cool dwarf, with a spectral type around M9.[5] With a visual magnitude of 15 and separated from the primary by only three arcseconds, it can only be seen with a powerful telescope.[3] It is estimated to be around 10 billion years old, although the properties of such low-mass stars are very similar across a wide range of ages. It is calculated have only 8% of the mass of the Sun, a tenth of its radius, and with a temperature of about Script error: No such module "val". it produces less than a thousandth of its luminosity.[5]
Spectroscopic companion
Script error: No such module "Labelled list hatnote". In 1989, a companion object, HD 114762 Ab, was found orbiting HD 114762 A by Latham, et al., using Doppler spectroscopy,[11] but its existence was not confirmed until 1991 by Cochran, et al.[12] Its orbital distance and revolution is similar to that of Mercury, though it has twice the eccentricity.[12] It has a minimum mass of Template:Jupiter mass, and thus was originally thought to be a massive exoplanet; however, in 2019, its inclination was determined by Gaia astrometry, giving it a true mass of Template:Jupiter mass. This makes it a red dwarf star, or a massive brown dwarf.[4] A 2020 study provided further confirmation of this, and revised the mass upwards to Template:Jupiter mass,[7] and in 2022 this mass was revised upwards still further, to Template:Solar mass, based on Gaia DR3 data and a similar upwards revision to the mass of the primary star.[6]
References
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- ↑ a b c d e Template:Cite Gaia DR3
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- ↑ Template:Cite simbad
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