This lab explores the Ring Nebula, also known as M57 or NGC 6720, a textbook example of a so-called planetary nebula. The goal is to understand it in terms of mass loss rate. You will also look to see how much of this mass loss rate is responsible for the birth of the next generation of stars.

We will use the Properties of Planetary Nebulae exercise from the University of Washington Astronomy Clearing House. The exercise includes a worksheet which you are to fill out. You are free to work in pairs. If you do so, please be sure to put both your names on the worksheet.

There are some trivial typo's on the worksheet. The first "4)" in Part A should be "3)". The second "5)" in Part C should be "6)".

In addition to the questions on the worksheet, please also answer the following:

• In Part B, question 5, also calculate the size of the nebula in parsecs, and compare it to the distance from the Sun to our nearest star.
• In Part C, question 3, also calculate the number density n, in atoms per cubic centimeter, assuming the entire density is from atoms of some species that you know is present. Is your value high, low, or about the same as compared to the typical density in the interstellar medium?

If you'd like to learn more about the Ring Nebula, consider this article which made careful spectroscopic measurements to test various models of the shape of the nebula.