1 research outputs found
Chromospheric Activity of HAT-P-11: an Unusually Active Planet-Hosting K Star
Kepler photometry of the hot Neptune host star HAT-P-11 suggests that its
spot latitude distribution is comparable to the Sun's near solar maximum. We
search for evidence of an activity cycle in the CaII H & K chromospheric
emission -index with archival Keck/HIRES spectra and observations from the
echelle spectrograph on the ARC 3.5 m Telescope at APO. The chromospheric
emission of HAT-P-11 is consistent with a year activity cycle,
which plateaued near maximum during the Kepler mission. In the cycle that we
observed, the star seemed to spend more time near active maximum than minimum.
We compare the normalized chromospheric emission index of
HAT-P-11 with other stars. HAT-P-11 has unusually strong chromospheric emission
compared to planet-hosting stars of similar effective temperature and rotation
period, perhaps due to tides raised by its planet.Comment: 16 pages, 8 figures; accepted to the Astrophysical Journa