Eta2 Hydri b

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.

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 (sidereal)	711±8 d
Time of periastron	2,451,420
Argument of periastron	351.5±9.5
Semi-amplitude	105±8
Star	Eta2 Hydri
Physical characteristics
Mass	>6.54 MJ

References

• Setiawan, J.; Rodmann, J.; Da Silva, L.; Hatzes, A. P.; Pasquini, L.; Von Der Lühe, O.; De Medeiros, J. R.; Döllinger, M. P.; Girardi, L. (2005). "A substellar companion around the intermediate-mass giant star HD 11977". Astronomy & Astrophysics. 437 (2): L31 – L34. arXiv:astro-ph/0505510. Bibcode:2005A&A...437L..31S. doi:10.1051/0004-6361:200500133. S2CID 6362483.

External links

• "HD 11977 B, a planet around a giant star". Max-Planck-Institut für Astronomie. Archived from the original on March 14, 2007. Retrieved 2008-07-03.
• "Notes for planet HD 11977 b". Extrasolar Planets Encyclopaedia. Retrieved 2008-07-03.