HD 217107 c
HD 217107 c is an extrasolar planet similar to Jupiter that orbits its star HD 217107 once every eight years. It was identified in 2005 as the second planet after HD 217107 b as the star's satellite. Its mass and orbital parameters are still not exactly known and can only be narrowed down.
discovery
As early as 1998, measurements of the radial velocity of the star HD 217107 revealed deviations that could be explained by the presence of a planet orbiting the star in 7.1 days. Since this planet, HD 217107 b, had an eccentricity of its orbit that was atypical for such planets , the existence of a second planet was postulated. Long-term observations of the star revealed a second deviation that had a period of 8 years and pointed to a planet that had to have at least twice the mass of Jupiter and whose distance to the star had to be at least a few astronomical units . This confirmed the existence of HD 217107 c in 2005.
Data
HD 217107 c has a semi-major axis of 4.41 ± 0.21 astronomical units, an eccentricity of 0.537 ± 0.026, an orbital period of 3352 ± 157 days (9.18 ± 0.43 years), and a mass greater than 2.5 ± 0.48 masses of Jupiter .
Web links
- SIMBAD: HD 217107
- The exoplanet in the "Encyclopedia of Extrasolar Planets"
- Extrasolar Visions: HD 217107 c ( Memento from February 11, 2012 in the Internet Archive )
Notes and evidence
- ↑ Fischer et al. : Planetary Companions around Two Solar-Type Stars: HD 195019 and HD 217107 . In: Publications of the Astronomical Society of the Pacific . 111, No. 755, 1999, pp. 50 - 56.
- ↑ Fischer et al. : Planetary Companions to HD 12661, HD 92788, and HD 38529 and Variations in Keplerian Residuals of Extrasolar Planets . In: The Astrophysical Journal . 551, No. 2, 2002, pp. 1107 - 1118. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Vogt et al. : Five New Multicomponent Planetary Systems . In: The Astrophysical Journal . 632, No. 1, 2005, pp. 638 - 658. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
