Southern HK project Metcalfe et al. (2009, arXiv: ) Small telescopes at CTIO run by SMARTS partners: Yale, GSU, STScI, et al. Service observing 2-3x per month using RC Spec with R ~ 2500 at Ca HK Monitor bright southern asteroseismic targets for stellar activity variations

HD (  Hor) Shortest measured stellar activity cycle in a solar- type star: 1.6 years Sampling permits some indication of the rotation rate: ~3x solar (8.5 days) Coronal activity cycle found from XMM x-ray measurements Metcalfe et al. (2010) Sanz Forcada et al. (2013)

 Eri: exoplanet host Jovian-mass exoplanet in ~7 year orbit from radial velocity observations Magnetic activity ruled out as the source of RV signal using Ca HK data Exoplanet confirmed from astrometric orbit with HST fine guidance sensors Hatzes et al. (2000) Benedict et al. (2006)

Ca HK observations Metcalfe et al. (2013)

 Eri: dual magnetic cycles Recent data since 1994 show coherent cycle with short period ~3 years Archival data from Mount Wilson also reveal long period cycle ~13 years Artificial data with two periods: remaining peaks are artifacts of sampling Metcalfe et al. (2013)

Short cycle grand minimum? Metcalfe et al. (2013)

Future prospects Bad news: the SMARTS low-res spectrograph was decommissioned in Feb 2013, bringing the southern HK project to an unexpected end. Good news: an archive of the time-series Ca HK measurements since 2007 is publicly available at (collaborations welcome). More good news: Las Cumbres Observatory Global Telescope (LCOGT) network will have medium-res spectrographs with Ca HK in 2015.