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.

• 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.

• "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.