Eta2 Hydri
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| Observation data Epoch J2000.0 |
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| Constellation (pronunciation) |
Hydrus | |
| Right ascension | 01h 54m 56m | |
| Declination | -67° 38' 50" | |
| Apparent magnitude (V) | +4.68 | |
| Characteristics | ||
| Spectral type | G8.5III | |
| U-B color index | ? | |
| B-V color index | ? | |
| V-R color index | ? | |
| R-I color index | ? | |
| Variable type | none | |
| Astrometry | ||
| Radial velocity (Rv) | -16.2 km/s | |
| Proper motion (μ) | RA: 76.00 mas/yr Dec.: 73.17 mas/yr |
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| Parallax (π) | 15.04 ± .49 .40 1 mas | |
| Distance | 216.89 ly (66.53 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 | |
| Planet | ||
| Companion |
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| Other designations | ||
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HD 11977, HR 570, HIP 8928....
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Eta2 Hydri (η2 Hyi / η2 Hydri) is a yellow giant star approximately 217 light-years away in the constellation 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.
In 2005, the giant planet Eta2 Hydri b was found in orbit.
[edit] References
- Setiawan, J., Rodmann, J., da Silva, L., Hatzes, A., Pasquini, L., von der Lühe, O., de Medeiros, J., Döllinger, M., Girardi, L. (2005). "A substellar companion around the intermediate-mass giant star HD 11977". Astronomy & Astrophysics 437: L31 – L34. doi:.
[edit] See also
[edit] External links
- Extrasolar Planets Encyclopaedia: Notes for star HD 11977
- Extrasolar Visions: HD 11977
- SIMBAD: HD 11977
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