M27 – The Dumbbell Nebula – Narrowband

The Dumbbell nebula in Vulpecula (the Fox) is a famous Messier object usually imaged in broadband RGB filters. It is displayed as such in an earlier post on this site (see here).

Although that post also displays an image with the hydrogen-alpha signal added, that imaging run did not at the time accumulate sufficient signal with the OIII and SII filters to produce a full narrowband image, as the outermost parts of the nebula are relatively faint.

This post attempts to rectify that by incorporating a much deeper OIII image along with more SII. The latter signal remains relatively faint and had to be boosted to reveal itself in this image.

The nebula is displayed in the Hubble (SHO) pallette. Exposure times were SII 12.5 hrs, H-α 8hrs, OIII 26 hrs.

In order to display the stars with correct colours, data from the original RGB imaging run was used, exposure times being: Red 3.5 hrs, Green 3 hrs, Blue 4 hrs. In post-processing the stars were removed from the narrowband image and replaced by those from the broadband run.

M27 is a planetary nebula – not a planet but a shell of expanding gas thrown off by a solar-mass star nearing the end of its life. Following its red giant stage, the Sun is expected to develop a planetary nebula of its own, before shrinking to become a white dwarf.

Planetary nebulæ are relatively short-lived on astronomical timescales, typically lasting around 20,000 years before dispersing into the interstellar medium.

Equipment: Planewave CDK14 corrected Dall-Kirkham telescope, Finger Lakes Instrumentation P9000 CCD camera, Astrodon RGB and 3nm narrowband filters, Monster Moag off-axis guider with Starlight Xpress Lodestar Pro guide camera.

Acquisition software: ACP Expert Scheduler, Maxim/DL. Image processing: PixInsight.