Featured Image: Reddened Stars Reveal Andromeda’s Dust

As distant light travels on a path toward us, it can be absorbed by intervening, interstellar dust. Much work has been done to understand this “dust extinction” in the Milky Way, providing us with detailed information about the properties of the dust in our galaxy. Far less, however, is known about the dust extinction of other galaxies. The image above, taken with the ultraviolet space telescope GALEX, identifies the locations of four stars in the nearby Andromeda galaxy (click for a full view!) that are reddened due to extinction of their light by dust within Andromeda. In a recent study led by Geoffrey Clayton (Louisiana State University), new, high-signal-to-noise spectra were obtained for these four stars using Hubble’s Space Telescope Imaging Spectrograph. These observations have allowed the authors to construct dust extinction curves to carefully study the nature of Andromeda’s interstellar dust. To learn about the results, see the paper below.


Geoffrey C. Clayton et al 2015 ApJ 815 14. doi:10.1088/0004-637X/815/1/14