HD 217107 b
A hot Jupiter with an eccentric orbit in Pisces.
HD 217107 b is an extrasolar planet roughly 65 light-years away in the constellation Pisces. It orbits the star HD 217107 every seven days, classifying it as a hot Jupiter. Its somewhat eccentric orbit helped scientists confirm a second planet in the system.
Quick Facts
- Discoverer
- Marcy et al.
- Discovery site
- United States
- Discovered
- November 24, 1998
- Discovery method
- Doppler spectroscopy
- Apsis
- astron
- Time periastron
- 2455201.109, 0.014
- Arg peri
- 22.78, 0.71, 0.70
- Semi-amplitude
- 140.30, 0.40
Facts from the source article.
Discovery
The planet was detected through small variations in the radial velocity of HD 217107, caused by the gravitational pull of the orbiting body. A 1998 study of the star's radial velocity revealed a 7.1-day cycle in its motion along the line of sight. The period and amplitude indicated a planetary companion with a minimum mass slightly greater than Jupiter's. The planet's mean distance from the star is less than one fifth of Mercury's distance from the Sun. Unlike most planets with orbital periods under 10 days, HD 217107 b has a somewhat eccentric orbit. Its discoverers hypothesized that a second planet several astronomical units away might cause this eccentricity. Confirmation of that second planet, HD 217107 c, came in 2005.
Frequently Asked Questions
Who discovered HD 217107 b?
HD 217107 b was discovered by Marcy et al.
When was HD 217107 b discovered?
HD 217107 b was discovered on November 24, 1998.
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