Astronomy:Eta2 Hydri b

Short description: Extrasolar planet in the constrellation Hydrus

Eta² Hydri b

Discovery
Discovered by	Setiawan et al.
Discovery site	Chile, La Silla
Discovery date	25 May 2005
Detection method	Radial velocity
Orbital characteristics
Semi-major axis	1.93 AU (289,000,000 km)
Eccentricity	0.40±0.07
Orbital period	711±8 d
astron|astron|helion}}	2,451,420
astron|astron|helion}}	351.5±9.5
Semi-amplitude	105±8
Star	Eta2 Hydri
Physical characteristics
Mass	>6.54 |♃|J}}}}}}

Eta² Hydri b (η² Hyi b, η² Hydri b), commonly known as HD 11977 b, is an extrasolar planet that is approximately 217 light-years away in the constellation of Hydrus. The presence of the planet around an intermediately massive giant star provides indirect evidence for the existence of planetary systems around A-type stars.

References

• Setiawan, J.; Rodmann, J.; Da Silva, L.; Hatzes, A. P.; Pasquini, L.; Von Der Lühe, O.; De Medeiros, J. R.; Döllinger, M. P. et al. (2005). "A substellar companion around the intermediate-mass giant star HD 11977". Astronomy & Astrophysics 437 (2): L31–L34. doi:10.1051/0004-6361:200500133. Bibcode: 2005A&A...437L..31S. http://www.aanda.org/articles/aa/full/2005/26/aahb021/aahb021.html. 

External links

• "HD 11977 B, a planet around a giant star". Max-Planck-Institut für Astronomie. Archived from the original on March 14, 2007. https://web.archive.org/web/20070314061322/http://www.mpia.de/homes/setiawan/hd11977_english.html. Retrieved 2008-07-03. 
• "Notes for planet HD 11977 b". Extrasolar Planets Encyclopaedia. https://exoplanet.eu/catalog/hd_11977_b--285/. Retrieved 2008-07-03.