Welcome to week two of "Analyzing the Universe". This week we will be exploring some of the means we have at our disposal to find out many things about the stars. It is really quite incredible that these tiny pinpoints of light can yield so much information about their nature and about the structure of the Universe as a whole. And if this is your first visit to the course, welcome and jump right in!

This week is our first in-depth look at an x-ray source, and it involves a white dwarf in a binary system. So sharpen up your detective skills, keep your copy of DS9 at the ready, and let's get down to business. It should be an exciting week.

This week we turn our attention to another fascinating cosmic source, discovered in the infancy of x-ray astronomy: Cen X-3. In so doing, we will see how binary stars can determine and influence many of the interesting and surprising features of our observations.

This week, we will be examining supernovae, and their remnants. These fascinating objects are the breeding grounds for future stars, and were the sources of virtually all the atoms that make up our solar neighborhood. Every atom of calcium in every bone in your body, for example, was once shot out of a supernova, billions of years ago.

This week we wrap things up with trips to galaxies and exotic objects, seen long ago and far away. The mysterious quasars provide clues about the way our Universe is evolving in time. They are incredible objects (actually, come to think of it, what isn't incredible in the x-ray sky?) discovered almost exactly a half century ago, quite by accident. We will explore the astonishingly prodigious x-ray output of 3C 273, one of the nearest ones, at a mere 2.5 billion light years away.