| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Hydrus |
| Right ascension | 01h 54m 56.13s [1] |
| Declination | -67° 38′ 50.3″ [1] |
| Apparent magnitude (V) | +4.68 |
| Characteristics | |
| Spectral type | G8.5III |
| B−V color index | 0.931 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | -16.2 km/s |
| Proper motion (μ) | RA: 76.22 ± 0.14 [1] mas/yr Dec.: 72.94 ± 0.17 [1] mas/yr |
| Parallax (π) | 14.91 ± 0.16[1] mas |
| Distance | 219 ± 2 ly (67.1 ± 0.7 pc) |
| Absolute magnitude (MV) | +0.57 |
| Details | |
| Mass | 1.91 M☉ |
| Radius | 10.09 R☉ |
| Luminosity | 55.5 L☉ |
| Temperature | 4970 K |
| Metallicity | -0.21 [Fe/H] 0.61 |
| Rotation | 230 d |
| Age | 500 - 2000 Million years |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta2 Hydri (η2 Hyi, η2 Hydri), often catalogued as HD 11977, is a yellow giant star approximately 219[1] light-years away in the constellation of Hydrus. Based on its mass, it was probably a class A star (similar to Vega or Fomalhaut) when it was on the main sequence, though it is now in the giant stage of its evolution. As of 2005, an extrasolar planet was confirmed to be orbiting the star.
Contents |
In 2005, the giant planet Eta2 Hydri b was found in orbit around Eta2 Hydri.[2]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity |
|---|---|---|---|---|
| b | >6.54 MJ | 1.93 | 711±8 | 0.40±0.07 |
Coordinates: 01h 54m 56s, −67° 38′ 50″
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