Session Organizers:
Andrew Mann (University of Texas at Austin),
Eric Gaidos (University of Hawaii at Manoa),
Adam Kraus (University of Texas at Austin)
Tabetha Boyajian (Yale University)

Touchstones are stones used to verify the authenticity and purity of precious metals. By analogy stars where stellar parameters (temperature, mass, radius, etc.) have been precisely established by direct observations (e.g., eclipsing binaries, wide binaries, astroseismology, interferometry). These stars can test models of stellar evolution and atmospheres and be used to develop empirical methods to determine the stellar properties of other stars.

The growing use of cool touchstone stars compels a better understanding of how their properties were determined, and also how they can be used to study stellar properties more generally. Important questions include:
-What assumptions are made when using a given technique (e.g., astroseismology)?
-What stellar characteristics can we safely infer from each method?
-How well do touchstone stars from different sources agree, and if there is disagreement what is the cause?
-What do the parameters of touchstone stars tell us about the reliability of stellar models?
-How will new instrumentation and observations (e.g., Gaia) widen our grid of touchstone stars and improve our understanding of cool stars?

This splinter session will bring together members of the astronomical community to discuss the above questions (and others). This will include a number of (short) talks on studies and uses of touchstone stars, with extra time for questions and discussion. The last 30 minutes of the session will be reserved for a panel discussion (comprised of the speakers) to help open up the dialogue for a broader discourse.

Preliminary Program:
2:00 - 2:20: Precise stellar diameters and temperatures from interferometry and transit light curves (Kaspar von Braun)
2:20 - 2:40: Astroseismology with Kepler (Dan Huber)
2:40 - 3:00: Testing stellar evolution model physics with touchstone stars (Gregory Feiden)
3:00 - 3:20: Improved mass-radius-magnitude relations from low-mass eclipsing binaries (Philip Muirhead)
3:45 - 4:00: Speaker
4:15 - 4:30: Speaker
4:30 - 5:00: Panel Discussion