HD 9446
HD 9446 is a star located about 164 light-years away in the constellation of Triangulum, near the southwestern constellation border with Pisces. This object can be viewed with binoculars or a telescope, but it is too faint to be seen with the naked eye at its apparent visual magnitude of 8.35. It is drifting further away from the Sun with a radial velocity of +21 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Triangulum |
| Right ascension | 01h 33m 20.1848s |
| Declination | +29° 15′ 54.5390″ |
| Apparent magnitude (V) | 8.35 |
| Characteristics | |
| Spectral type | G5V |
| B−V color index | +0.680±0.015 |
| Astrometry | |
| Radial velocity (Rv) | +21.2±3.1 km/s |
| Proper motion (μ) | RA: 190.249±0.140 mas/yr Dec.: −53.650±0.201 mas/yr |
| Parallax (π) | 19.8336 ± 0.1376 mas |
| Distance | 164 ± 1 ly (50.4 ± 0.3 pc) |
| Absolute magnitude (MV) | 4.76 |
| Details | |
| Mass | 1.00±0.10 M☉ |
| Radius | 1.00 R☉ |
| Luminosity | 1.1 L☉ |
| Surface gravity (log g) | 4.53±0.16 cgs |
| Temperature | 5,793±22 K |
| Metallicity [Fe/H] | 0.09±0.05 dex |
| Rotational velocity (v sin i) | 4±1 km/s |
| Age | 2.0±1.5 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
This object is a G-type main sequence star with a stellar classification of G5V. The physical properties this star appear similar to the Sun, making it a candidate solar analog. However, the measured abundance of elements with more mass than helium is outside the accepted range. It is roughly two billion years in age and has an active chromosphere. The amount of activity measured in the chromosphere corresponds to a star with a rotation period of about 10 days.
On 5 January 2010, scientists announced the discovery of two planets orbiting around HD 9446.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.687±0.0056 MJ | 0.1892±0.0065 | 30.0608+0.0034 −0.0033 |
0.20±0.06 | — | — |
| c | ≥ 1.71±0.13 MJ | 0.646±0.022 | 189.6±0.13 | 0.06±0.06 | — | — |