NOAO >   Observing Info >   Approved Programs >   2018A-0297

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Program Information for 2018A-0297


PI: Paul Wilson Cauley, Arizona State U., pwcauley@gmail.com
Address: School of Earth and Space Exploration, PO Box 871404, Tempe, AZ 85287 USA

CoI: Evgenya Shkolnik, Arizona State U.
CoI: Joe Llama, Lowell Observatory

Title: Magnetic Star-Planet Interactions in HAT-P-11 and WASP-69

Abstract: Massive planets that orbit within $approx 15 R_*$ of their host stars can have a measureable impact on activity levels in the stellar chromosphere via magnetic reconnection events between the stellar and planetary magnetospheres. The energy budget in these star-planet interactions (SPI) offers a potential window into the strength of the planetary magnetic field, a currently unconstrained parameter for exoplanets yet one that is critical, e.g., for atmospheric mass loss. SPI have been observed in Ca II H and K, UV, and X-rays for a handful of Jupiter-mass planets orbiting solar-like stars. However, little effort has been made to search for SPI around K and M-dwarf planet hosts, where, due to stronger stellar magnetic fields, the dissipated energy should be greater than for earlier type stars as it is proportional to $B_*^{4/3}$. Here we propose to monitor the Ca II H and K lines in two promising cool star SPI candidates, HAT-P-11 and WASP-69, in order to search for variability as a function of planetary orbital phase. Both HAT-P-11 and WASP-69 show activity levels above the average level for planet-hosting stars of a similar spectral type and age, potential evidence that their planets are influencing the stellar activity level.

Program Type: Standard/NASA WIYN

Scheduled Nights:
Run 1 (2018A):  WIYN/HYDR -- 5n on May 31 - Jun 04 2018


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



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