Wednesday 12 Jul 2017Solving the M-dwarf Luminosity Problem

Mr. Sam Morrell - University of Exeter

Physics, 4th Floor 14:00-15:00

It is shown in Stauffer et al. 2007 and Bell et al. 2012 that M-dwarf stars cooler than about 4000K exhibit half as much flux at optical wavelengths than is suggested by their equivalent stellar models. This can cause the ages of stars in young clusters, (less than 10Myr in age), to be underestimated by a factor of 2-3 depending on choice of colour. Not only does this in turn cause large discrepancies with planet formation timescales, but the excess flux in the models can drastically affect many other fields of study, including exoplanet climatology.

By observing visible spectra of stars in the Pleiades and Praesepe, two clusters for which we have well understood memberships, ages and metallicities, and deriving robust flux calibrations for those spectra, we can directly compare them to the suspect stellar models. In this seminar I will present our motivations, method and initial findings for this project.

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