Introduction

Have you ever wondered how astronomers learn about objects in the Universe if they can’t visit them in person? Nearly everything we know about the stars and galaxies in the Universe comes from the light we receive from these objects. Fortunately, that light contains a wealth of information. In this investigation, you will learn how astronomers use light and filters to investigate stars and galaxies.

LBN 777 gas and dust cloud
LBN 777 is a large cloud of gas and dust. The brownish color is caused by large dust grains embedded in the gas. Credit: T.A. Rector and H. Schweiker (WIYN and NOAO/AURA/NSF)