Английская Википедия:HD 177830
Шаблон:Short description Шаблон:Starbox begin Шаблон:Starbox observe Шаблон:Starbox character Шаблон:Starbox astrometry Шаблон:Starbox detail Шаблон:Starbox catalog Шаблон:Starbox reference Шаблон:Starbox end HD 177830 is a 7th magnitude binary star system located approximately 205 light-years away in the constellation of Lyra. The primary star is slightly more massive than the Sun, but cooler being a type K star. Therefore, it is a subgiant clearly more evolved than the Sun. In visual light it is four times brighter than the Sun, but because of its distance, about 204 light years, it is not visible to the unaided eye. With binoculars it should be easily visible.
The primary star is known to have two extrasolar planets orbiting around it.
Stellar system
The secondary star is a Red dwarf star orbiting at a distance of 100 to 200 AU with a likely period of roughly 800 years.[1]
Planetary system
On November 1, 1999,[2] the discovery of a planet HD 177830 b was announced by the California and Carnegie Planet Search team using the very successful radial velocity method and an analysis on data released by the team performed by amateur astronomer Peter Jalowiczor along with two other planets. This planet is nearly 50% more massive than Jupiter (Шаблон:Jupiter mass) and takes 407 days to orbit the star in an extremely circular orbit.[3] In 2000 a group of scientists proposed, based on preliminary Hipparcos astrometrical satellite data, that the orbital inclination of HD 177830 b is as little as 1.3°. If that was the case, the planet would have a mass of Шаблон:Jupiter mass, making it a brown dwarf instead of a planet. However, it is very unlikely that the planet would have such orbit. Furthermore, brown dwarfs with short orbits around solar-mass (Шаблон:Solar mass) stars are exceedingly rare (the so-called "brown dwarf desert") making the claim even more unlikely.
On November 17, 2010, the discovery of a second planet HD 177830 c was announced along with four other planets. The planet has 50% the mass of Saturn and takes 111 days to orbit the star in a very eccentric orbit. This planet is in a near 4:1 resonance with the outer planet.[4]
Шаблон:OrbitboxPlanet begin Шаблон:OrbitboxPlanet Шаблон:OrbitboxPlanet Шаблон:Orbitbox end
See also
- List of exoplanets discovered before 2000 - HD 177830 b
- List of exoplanets discovered in 2010 - HD 177830 c
References
- ↑ Ошибка цитирования Неверный тег
<ref>; для сносокRoberts2015не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокKeckне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокVogt2000не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокMeschiari2011не указан текст
- Английская Википедия
- Henry Draper Catalogue objects
- Hipparcos objects
- Lyra
- K-type subgiants
- Planetary systems with two confirmed planets
- Durchmusterung objects
- Binary stars
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