HD 217107 b

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HD 217107 b is an exoplanet that orbits the Sun-like star HD 217107 every 7.1 days. It is the innermost known star in its planetary system and was discovered by the California and Carnegie Planet Search team . Due to its size and its proximity to the central star, the planet is assigned to the type " hot Jupiter ".

discovery

HD 217107 b was found by measuring the radial velocity . Small fluctuations with a period of 7.1 days were found in the radial speed. The period and amplitude of the deviation indicated a relatively large companion orbiting the star in those 7.1 days. Mathematical models resulted in a mass for HD 217107 b that is only slightly larger than that of Jupiter, perfect.

It could be shown that the semi-major axis of the planet is 0.074 (± 0.002) AU. The eccentricity of the orbital ellipse is 0.13 (+/- 0.02), the circulation time 7.1269 (± 0.00022) days, the mass of the planet is in the range of 1.37 (± 0.14) Jupiter masses confined .

Reference to the second planet

Planets orbiting this close to their sun tend to have very circular orbits. Therefore, the eccentricity found at HD 217107 b indicated the presence of a second planet relatively far from the star. Long-term observation of the star HD 217107 confirmed the existence of a second planet, HD 217107 c , in 2005.

Individual evidence

  1. ↑ 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. doi : 10.1086 / 316304 .
  2. ↑ Vogt et al. : Five New Multicomponent Planetary Systems . In: The Astrophysical Journal . 632, No. 1, 2005, pp. 638 - 658. doi : 10.1086 / 432901 .
  3. ↑ 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. doi : 10.1086 / 320224 .

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