M27 – The Dumbbell Nebula

M27, known as the Dumbbell Nebula, is a planetary nebula in the constellation Vulpecula, about 1360 light years from Earth. These images are among the first I acquired while learning and experimenting with the telescope, camera, and color filters.

M27 in Natural Light

See M27 in narrowband light

The goal for this image was to collect as much luminance as possible to reduce background noise. With nearly three hours exposure, the image looks better than earlier attempts. The following night I got an hour apiece for the color images unbinned, and that worked fairly well. (It would have been better to bin the color frames 2x2 for this LRGB image. Doing so would have collected more color data, providing a better signal-to-noise ratio.)

M27 in Narrowband Light

See M27 in natural-color light

This narrowband image reveals the extent of M27's ionized gas with 30-minute sub-exposures (now that our differential flexure problem is resolved). Notice how the nebulosity visible here covers a much larger area than in the natural-color image above, especially above and below the main nebula. For example, the green texture in the lower-right corner is a patch of ionized hydrogen gas, and another patch (mixed with ionized oxygen) is visible at the top-center.

This image assigns sulfur-II to the red channel, hydrogen-alpha to the green channel, and oxygen-III to the blue channel (this is the same palette used by the Hubble Space Telescope for its false-color images).

Updated May 5, 2024