2012/09/06 by Guillermo Torres, G. Torres
Physics and Astronomy · Social Sciences · #Astronomy and Astrophysical Research #Educational Leadership and Practices #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1002/asna.201211743
7 pages, to appear in the Proceedings of the 17th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, eds. K. Strassmeier & M. Lopez-Morales (AN, Vol. 334)
arxiv created 2012/09/06 · openalex publication_date 2013/02/01 · arxiv updated 2015/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The field of exoplanet research has revitalized interest in M dwarfs, which have become favorite targets of Doppler and transit surveys. Accurate measurements of their basic properties such as masses, radii, and effective temperatures have revealed significant disagreements with predictions from stellar evolution theory in the sense that stars are larger and cooler than expected. These anomalies are believed to be due to high levels of activity in these stars. The evidence for the radius discrepancies has grown over the years as more and more determinations have become available; however, fewer of these studies include accurate determinations of the temperatures. The ubiquitous mass-radius diagrams featured in many new discovery papers are becoming more confusing due to increased scatter, which may be due in part to larger than realized systematic errors affecting many of the published measurements. A discussion of these and other issues is given here from an observer's perspective, along with a summary of theoretical efforts to explain the radius and temperature anomalies.