A casual glance at the constellation shows numerous faint stars punctuated by several brighter stars. However, a long-exposure photograph reveals subtleties in the star colors and intensities that may not easily be detected by the unaided eye (Fig. 1). While most of the stars appear as faintly colored specks of light, the stars outlining the figure of Orion are brilliant. Betelgeuse and Rigel are two of the brightest stars in the evening sky. Easily apparent is the ruddy red tint of Betelgeuese and the blue hue of Rigel. Upon closer inspection, we see that one of the stars in Orion’s sword is not a star at all, but rather a diffuse patch of red gas (Fig.2) . Why do the stars in Orion look so different from each other? To answer this question we must understand the story told to us by starlight.

Figure 1
The constellation of Orion with the primary members labeled. Orion is generally pictured to be the figure of a man; Betelgeuse and Bellatrix mark his right and left shoulders, respectively, while Rigel and Saiph mark his left and right knees. Alnitak, Alnilam and Mintaka mark his belt, while the line of stars including the Orion Nebula make up his sword. Many of the unlabeled fainter stars in the image are members of the Orion Association as well. Photograph taken by the author.

Figure 2
Closer view of the star-forming region known as the Orion Nebula. This glowing cloud of gas and dust contains thousands of newly forming stars, most of them hidden from our view. Photograph taken by the author using the 6" Goto refractor at Mt. Wilson Observatory.