HD 219828
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Star HD 219828 |
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| AladinLite | |||||||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Pegasus | ||||||||||
| Right ascension | 23 h 18 m 46.74 s | ||||||||||
| declination | + 18 ° 38 ′ 44.6 ″ | ||||||||||
| Apparent brightness | 8.04 mag | ||||||||||
| Typing | |||||||||||
| Known exoplanets | 1 | ||||||||||
| Spectral class | G0 IV | ||||||||||
| Astrometry | |||||||||||
| Radial velocity | (−24.2 ± 0.3) km / s | ||||||||||
| parallax | (13.83 ± 0.74) mas | ||||||||||
| distance | (236 ± 13) ly (72.3 ± 4) pc |
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| Visual absolute brightness M vis | +3.7 mag | ||||||||||
| Proper movement | |||||||||||
| Rec. Share: | (−4.15 ± 0.84) mas / a | ||||||||||
| Dec. portion: | (+4.14 ± 0.70) mas / a | ||||||||||
| Physical Properties | |||||||||||
| Dimensions | (1.2 ± 0.1) M ☉ | ||||||||||
| Luminosity |
8 L ☉ |
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| Effective temperature | (5891 ± 18) K. | ||||||||||
| Metallicity [Fe / H] | 0.19 ± 0.03 | ||||||||||
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Other names and catalog entries |
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HD 219828 is the name of a star approx. 70 parsecs (approx. 240 light years ) away from the Sun , which is orbited by an exoplanet . The star in the constellation Pegasus is a subgiant of the spectral type G0 and with its apparent magnitude of 8.04 mag is invisible to the naked eye. With a surface temperature of approx. 5900 K, the star is relatively similar to the sun.
The planet
Due to the large number of newly found, extrasolar planets, newly discovered companions are no longer given proper names. Therefore the planet orbiting HD 219828 is simply called “b”, ie HD 219828 b. HD 219828 b is a planet similar to Neptune, and is at least 21 times as heavy as Earth. It is not yet known whether the object is an ice planet, a gas planet or even a stone planet, which would then be something like "super earth".
Web links
swell
- Melo et al .: A new Neptune-mass planet orbiting HD 219828 . In: Astronomy and Astrophysics . 467, May 2007, pp. 721-727. bibcode : 2007A & A ... 467..721M . doi : 10.1051 / 0004-6361: 20066845 .