Epsilon Eridani has been a target of searches for planetary systems for many years. The Figure shows a combination of Walker et al.'s (1995 Icarus 116, 359) 11.1 yr radial velocity (RV) series with our 7.3 yr series. Annual averages are plotted. This variation might be interpreted as the gravitational action of a substellar companion. However, Gray and Baliunas (1995 ApJ 441, 436) saw a period of 5 yr in epsilon Eri's Ca II H&K emission and in the velocity span of the star's absorption line bisectors, illustrated here by the open triangles. The correlation suggests that the apparent RV variation may be caused by the changes in granular convection in the star's photosphere. This may be the first discovery of a correlation between the apparent integrated-disk Doppler shift of a star and the star's magnetic cycle. This project is funded by grants from NASA, NSF, and private donors to Tom Gehrels' Spacewatch Project.
AAS/Division for Planetary Sciences Meeting Abstracts #28
- Pub Date:
- September 1996