Media

Enhancing Exoplanet Discovery and Characterization through Stellar Photometric “Flicker”

 

 

Dr. Fabienne Bastien Pennsylvania State University As a result of the high precision and cadence of surveys like MOST, CoRoT, and Kepler, we may now directly observe the very low-level light variations arising from stellar granulation in cool stars. Here, we discuss how this enables us to more accurately determine the physical properties of Sun-like stars, to understand the nature of surface convection and its connection to activity, and to better determine theproperties of planets around cool stars. Indeed, such sensitive photometric "flicker" variations are now within reach for thousands of stars, and we estimate that upcoming missions like TESS will enable such measurements for ~100 000 stars. We present recent results that tie “flicker” to granulation and enable a simple measurement of stellar surface gravity with a precision of 0.1 dex. We use this, together and solely with two other simple ways of characterizing the stellar photometric variations in a high quality light curve, to construct an evolutionary diagram for Sun-like stars from the Main Sequence on towards the red giant branch. We discuss further work that correlates “flicker” with stellar density, allowing the application of astrodensity profiling techniques used in exoplanet characterizationto many more stars. We also present results suggesting that the granulation of F stars must be magnetically suppressed in order to fit observations. Finally, we show that we may quantitatively predict a star's RV jitter using our evolutionary diagram, permitting the use of discovery light curves to help prioritize follow-up observations of transiting exoplanets.

 

 

Muonium, Positronium, Proton Radius, and all that

Dr. Michael Eides University of Kentucky I will discuss physics of exotic muonium and positronium atoms, high precision quantum electrodynamic calculations of energy levels, and determination of the electron-muon mass ratio. I'll introduce the proton radius puzzle, discuss briefly the experimental data on muonic hydrogen, deuterium, and helium, and explain the status of the respective theory.

Dr. Anne Sayers Interview

Chris Holbrook

Greenhouse Preview

Where were you? Woodrum

Carlos de la Torre, "The Promise and Perils of Populism: Global Perspectives"

“The Promise and Perils of Populism: Global Perspectives” ‒ is a panel discussion at 2-4 p.m. Friday, Jan. 23, in the James F. Hardymon Theatre in the UK Davis Marksbury Building. The program title is also the name of the just-released book edited by Carlos de la Torre, UK professor of sociology and director of the UK International Studies Program. Moderated by Emily Beaulieu, UK assistant professor of comparative politics, the panel will include de la Torre, Cas Mudde of the University of Georgia, Cristóbal Rovira Kaltwasser of Diego Portales University (Chile) and Ron Formisano, the William T. Bryan Professor of American History at the University of Kentucky.

Mr. Shapiro on using the UK Library

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