Southern HK project

Metcalfe et al. (2009, arXiv:0909.5464)

• 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 17051 ( 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 http://solar-stellar.org (collaborations welcome).

• More good news: Las Cumbres Observatory Global Telescope (LCOGT) network will have medium-res spectrographs with Ca HK in 2015.