HAT-P-11
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HAT-P-11, also known as GSC 03561-02092 and Kepler-3, is a metal-rich orange dwarf star located 123 light-years away in the constellation Cygnus. It is notable for its high proper motion and an unusually small radius attributed to an anomalously high helium fraction. The star has active latitudes generating starspots with coverage about 100 times greater than the Sun's.
Quick Facts
- Designations
- GSC 03561-02092, Kepler-3
- Distance
- 123 ly
- Constellation
- Cygnus
- Apparent magnitude
- 9.6
- Star type
- metal-rich orange dwarf
Facts from the source article.
Planetary system
The first exoplanet, HAT-P-11b, was discovered by the HATNet Project via the transit method and is believed to be slightly larger than Neptune. Its orbit is misaligned with the star's spin axis, having an obliquity of about 100°. Water vapor and ammonia have been detected in its atmosphere.
A radial velocity trend suggested an additional body, confirmed in 2018 as HAT-P-11c on an approximately nine-year orbit. In 2020, astrometric detection of HAT-P-11c allowed determination of its inclination and true mass. Multiple 2024 studies present conflicting results: one suggests the radial velocity variations may stem from a magnetic activity cycle, possibly indicating a different outer planet; another reaffirms the previously proposed planet; a third corroborates the planetary nature of HAT-P-11c with additional radial velocity data.
More in Planetary Systems with Two Confirmed Planets
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: HAT-P-11 (CC BY-SA 4.0).
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