Astro 1: Introductory Astronomy David Cohen Class 27: Tuesday, April 29 Spring 2014 http://apod.nasa.gov/apod/ap130927.html Andromeda Galaxy http://apod.nasa.gov/apod/ap130927.html Andromeda http://apod.nasa.gov/apod/ap130416.html M 51: The Whirlpool Galaxy http://apod.nasa.gov/apod/ap060219.html Messier 83: a (mildly) barred spiral http://apod.nasa.gov/apod/ap140128.html NGC 1300: a (significantly) barred spiral The Hubble sequence of galaxies not nearly as explanatory/fundamental as stellar types and the HR diagram are for stars Messier 87: elliptical galaxy (with several others) http://apod.nasa.gov/apod/ap110829.html an elliptical galaxy and a spiral galaxy http://apod.nasa.gov/apod/ap120914.html Centaurus A http://apod.nasa.gov/apod/ap100313.html NGC 7049: dusty spiral that otherwise looks like an elliptical - a merger product? http://apod.nasa.gov/apod/ap090408.html Large Magellanic Cloud (irregular galaxy and near neighbor to the Milky Way) the “Magellanic Stream” - gas being pulled out of the Magellanic Clouds (our nearby neighbor galaxies) by the gravity of the Milky Way http://apod.nasa.gov/apod/ap100125.html The Hydra cluster http://apod.nasa.gov/apod/ap120512.html a galaxy is stripped of its gas as it orbits around its cluster blue is X-ray emitting hot gas http://apod.nasa.gov/apod/ap140328.html Abell 2744: huge galaxy cluster, filled with X-ray emitting gas http://apod.nasa.gov/apod/ap110629.html http://apod.nasa.gov/apod/ap130308.html The Hubble Deep Field (multi-week exposure: 1000s of galaxies): this is a relatively empty part of the sky! http://apod.nasa.gov/apod/ap121014.html.