HD 984
HD 984 is the brightest star in this Sloan Digital Sky Survey image. The spiral galaxy NGC 47 can be seen at upper left. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 00h 14m 10.25283s |
| Declination | −07° 11′ 56.8127″ |
| Apparent magnitude (V) | 7.32 |
| Characteristics | |
| A | |
| Evolutionary stage | Main sequence |
| Spectral type | F7V |
| B−V color index | 0.522±0.01 |
| B | |
| Evolutionary stage | Brown dwarf |
| Spectral type | M6.5±1.5 |
| Apparent magnitude (J) | 13.28±0.06 |
| Apparent magnitude (H) | 12.6±0.05 |
| Astrometry | |
| Radial velocity (Rv) | 1.04±0.25 km/s |
| Proper motion (μ) | RA: 104.775 mas/yr Dec.: −68.016 mas/yr |
| Parallax (π) | 21.877±0.0249 mas |
| Distance | 149.1 ± 0.2 ly (45.71 ± 0.05 pc) |
| Absolute magnitude (MV) | 3.95±0.07 |
| Orbit | |
| Primary | A |
| Companion | B |
| Period (P) | 140+50 −30 yr |
| Semi-major axis (a) | 28+7 −4 AU |
| Eccentricity (e) | 0.76±0.05 |
| Inclination (i) | 120.8+1.8 −1.6° |
| Details | |
| A | |
| Mass | 1.2±0.06 M☉ |
| Radius | 1.247±0.053 R☉ |
| Luminosity | 2.218+0.142 −0.134 L☉ |
| Surface gravity (log g) | 4.38±0.06 cgs |
| Temperature | 6326±80 K |
| Metallicity [Fe/H] | −0.01±0.12 dex |
| Rotation | 1.39±0.05 days |
| Rotational velocity (v sin i) | 42.13±1.65 km/s |
| Age | 30–200 Myr |
| B | |
| Mass | 61±4 MJup |
| Radius | 0.162 R☉ |
| Luminosity | 1.318+0.094 −0.088×10−3 L☉ |
| Temperature | 2730+120 −180 K |
| Metallicity [Fe/H] | −0.62±0.02 dex |
| Rotational velocity (v sin i) | 12.72+0.03 −0.02 km/s |
| Position (relative to A) | |
| Component | B |
| Epoch of observation | 2015 |
| Angular distance | 201.6±0.4 mas |
| Position angle | 92.2±0.5° |
| Other designations | |
| BD−08 24, Gaia DR2 2431157720981843200, Gaia DR3 2431157720981843200, HIP 1134, SAO 128650, PPM 182008, TIC 408012676, TYC 4670-773-1, GSC 04670-00773, 2MASS J00141025-0711569 | |
| Database references | |
| SIMBAD | data |
HD 984 is a F-type main-sequence star located in the equatorial constellation Cetus. It is a young star, estimated 30 to 200 million years old, and is orbited by a brown dwarf companion. Parallax measurements by the Gaia spacecraft imply a distance of 150 light-years (46 pc) to HD 984. At an apparent magnitude of 7.32, the star is too dim to be visible to the naked eye.