Poster Presentation

A Photometric and Spectroscopic Study on the Be Star CD−49 3441 with Large Near-Infrared Excess and Peculiar Variations

Chien-De Lee (Institute of Astronomy, National Central University), Frederick Walter (Department of Physics and Astronomy, Stony Brook University), and Wen-Ping Chen (Institute of Astronomy, National Central University))

CD-49 3441 is a Be star far away from any star-forming regions, so is a classical Be star. However, it shows many peculiarities, like extremely strong Hα flux, forbidden lines, and has among the largest near-infrared excess—which must be accounted for by thermal dust emission—in all known classical Be stars. The star should be on the verge of turning off the main sequence, and the expanding envelope cools off and condenses to form dust grains, which reprocess starlight to produce the observed excessive infrared emission. We present the results of photometric and spectroscopic observations carried out in 2011–2012 for which nearly simultaneous spectroscopic and photometric variations of CD−49 3441 were first found. A positive correlation was found between the brightness and the Hα equivalent width, signifying the causality between the gas activity and stellar mass loss.