Astronomy Colloquium

I will provide an overview on progress and problems in understanding the structure of the Milky Way, with a focus on recent results on the stellar structure of the Galaxy using the Spitzer Space Telescope. This will include the most recent estimates on the distance to the center of the Galaxy (shorter than you might have thought), the parameters of the stellar bar(s) of the Galaxy (more complicated than you might have assumed), the number of stellar spiral arms of the Galaxy (fewer than you may have heard). I will also present recent work on the vertical scaleheight (and radial dependence) of the different components of the stellar Galaxy. The relation between the mass density of the Galaxy, traced by the mid-infrared light, and the galactic scale star formation will also be discussed.