Explore the fascinating facts and visual wonder of stars in this easy-to-read and beautifully illustrated guide from astrophysicist and popular science blogger Dr. Jillian Scudder. Stars, the building blocks of the universe, are simply luminous spheres of plasma held together by gravity, but there are many kinds and many remarkable examples. Astoundingly, there are at least 100 billion stars in our galaxy and an estimated two trilliongalaxies in our visible universe.Understanding the birth, life, and death of stars is key to a knowledge of astronomy. 40 Ways to Know a Star offers forty short essays that explore everything from the Milky Way to planetary nebulae, from how a star is born to the colors of stars, each enhanced by a color illustration or graphic image.