All colloquia are held in Mendel Hall except as noted.
Call the department office, (610)519-4820, for more information.

Date: Friday, March 27, 2009 Title: From Foreground Trash to Bountiful Treasure: Galactic Stratiagraphy, Magnetic Activity & the Kinematics of M Dwarfs in the Sloan Digital Sky Survey
Speaker: Dr. Andrew West From: MIT Time/Place:  Reception 2:30 pm in Mendel 455 -- Lecture 3:00 pm in Mendel 341 M dwarfs are the smallest stars in the Galaxy that can still fuse hydrogen. They can be 10 times less massive, twice as cool, and over 1000 times dimmer than the Sun. Yet despite their diminutive physical properties, M dwarfs make up ~75% of all of the stars in the Milky Way and have main sequence lifetimes that exceed trillions of years. Their dominance in the Galaxy make M dwarfs excellent tracers of both the structure and evolution of the local Milky Way. In addition, these little stars have intense stellar flares and strong magnetic fields that allow us to probe their interiors and may have important consequences for the habitability of planets that orbit them. I will present results from several M dwarf studies that have come out of the Sloan Digital Sky Survey (SDSS) and represent the largest photometric and spectroscopic M dwarf samples ever assembled (35 million and 50,000 stars respectively).
Date: Friday, March 20, 2009 Title: Treasure Hunting in Photometric Seas: A Systematic Search for Eclipsing Binary Stars
Speaker: Dr. Jonathan Devor From: Harvard Smithsonian Center for Astrophysics: Harvard University Time/Place:  Reception 2:30 pm in Mendel 455 -- Lecture 3:00 pm in Mendel 341 Eclipsing binaries provide the most direct and accurate method of measuring both the masses and radii of stars. We need to know both the masses and radii of stars to constrain their structure and to solve the ongoing discrepancy between theory and observations found in low mass dwarfs. Data from the OGLE II and TrES multi-epoch photometric surveys was analyzed using the automated DEBil/MECI pipeline. Low mass and abnormal eclipsing binaries were identified.