Science Seminars

3/17/2016- Travis Metcalfe; Breaking Magnetic Braking in Sun-like Stars

Speaker: Travis Metcalfe (SSI)
Date: Tuesday, Mar 17, 2020
Time: 4:00 PM
Location: SPSC N100

Seminar Abstract:

Precise photometry from the Kepler space telescope allows not only the measurement of rotation in solar-type field stars, but also the determination of reliable masses and ages from asteroseismology. These critical data have recently provided the first opportunity to calibrate rotation-age relations for stars older than the Sun. The evolutionary picture that emerges is surprising: beyond middle-age the efficiency of magnetic braking is dramatically reduced, implying a fundamental change in angular momentum loss beyond a critical Rossby number (Ro~2). I will discuss the rotation detection methods and asteroseismic modeling that provide these key data, and review recent efforts to expand the sample and minimize systematic uncertainties. I will conclude by presenting multiple lines of evidence that the Sun is in a transitional evolutionary phase, and that its magnetic cycle must represent a special case of stellar dynamo theory.