The Eagle Nebula (M16)
The cloudy weather lately has been bad news for Friday Night Star Parties but it has given us some time to reduce a back-log of pretty pictures the UIS Barber Observatory took over the summer. Below is an image of the Eagle Nebula (M16) in the constellation Serpens. The nebula gets its name from the dark silhouette at the center of the nebula that appears like an eagle flying from the lower left to upper right in this picture. The nebula itself is a cloud of gas about 7000 light-years from Earth that has been lit up by young massive stars forming in it. We picked this as a target because it covers a relatively wide field of view that shows off the capabilities of our CCD camera.
The colors in the picture are not “true” colors. A color image like this is made by taking three black and white images through different color filters and assigning each image the color of red, green, or blue. In this case we combined three 10 minute exposures in the V-band, R-band, and I-band filters. The combination mimics a color picture. The red and green channels are filters that roughly correspond to colors your eyes see as red and green. But the blue channel in this image is from the infrared I-filter image. We combined them this way because this was the most visually pleasing combination.
The red and blue streaks below some of the stars are because they were over exposed in the R and I filter images.