APOD: 2019 September 30 - Orion Rising over Brazil

Good morning, Rallypoint. Today's Astronomy Picture of the Day (APOD) is titled "Orion Rising over Brazil." This supine perspective of Orion is one that most of us in the Northern Hemisphere don't get to see. The shoulders of Orion are to the left (Betelgeuse, bottom; Bellatrix, top), and the feet of Orion to the right (Saiph, bottom; Rigel, top).

Orion's Belt is centered in the image, and Orion's Sword hangs off to the right. The sword contains the Orion Nebula (Messier 42). Betelgeuse is a red supergiant at least 300 times the Sun's diameter, and perhaps much more. It puts out about 100,000 times more energy than the Sun does, but its surface temperature is cooler than that of the Sun. This temperature difference gives the star a red-orange hue. Rigel is a blue supergiant. Like Betelgeuse, it is much bigger and heavier than the Sun. It's surface is thousands of degrees hotter, however, so it shines blue-white.