December’s Object to Observe: The Orion Nebula
Located in Orion’s “sword,” the Orion Nebula is a cavern of rolling dust and gas where thousands of stars are forming. The Orion Nebula is a picture book of star formation, from the massive, young stars that are shaping the nebula to the pillars of dense gas that may be the homes of budding stars. At 1,500 light-years away, the Orion Nebula is nearest star-forming region to Earth. It is one of the brightest nebulae, and is visible to the naked eye in the night sky.
Most nebula have been sculpted by stellar winds into a deep bowl. The darker regions are the outermost layers of gas, the rim of the bowl. The energy and stellar winds of four massive stars carve out a cavity in the region called the Trapezium. The flow of ultraviolet light disrupts the development of near by smaller stars.
M43 is a young massive star that illuminates a region in the Orion Nebula. Like a miniature Orion Nebula this star is hollowing out its own cavity in the landscape of gas and dust. Dark dense pillars of gas and dust hang from the nebula’s outer layers resisting the erosion from the intense ultraviolet light of Orion’s largest stars. Pillars always point to the stars that cause their erosion. These specific pillars point to the massive stars in the Trapezium region.
The glowing region reveals arcs and bubbles formed by stellar winds, streams of large particles ejected by stars. The faint red objects in the Orion Nebula are brown dwarfs, cool objects too small to sustain nuclear fusion in their cores. Brown dwarfs are sometimes referred to as “failed stars”.