The Lion Nebula

Officially known as Sh2-132, The Lion Nebula is around 10,000 light-years from Earth. Energetic stars are bombarding the surrounding gas with ultraviolet radiation, causing it to glow.


Version 2, reprocessed December 2022

From the Reprocessing Bonanza 2022. This version uses exactly the same data as version 1, but with better processing tools and skills. At 28 hours, this was my longest integration at the time. It was needed to bring out the faint nebulosity, but I remember having real trouble controlling the stars when processing the original version. The result was a decent enough image, but perhaps overly-peppered with stars. When reprocessing, BlurXTerminator helped to keep the stars nice and tight. I still like the original version, but do think that the reprocess has the edge.


Version 1, November 2021

This is a really faint nebula, and it’s still noisy even with 28 hours of integration. Scroll down for the source data and you’ll see that the nebula is barely visible in a single stretched sub, and even the integrated image is underwhelming. The noise level made it tough to process, but following my preferred workflow did bring out some nice colours. It’s a bit mad to image The Lion Nebula with an OSC camera from a city, but I like showing that it’s at least possible!

* October & November 2021
* Bristol, UK (Bortle 8)
* Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph
* Camera: ZWO ASI 2600MC-PRO
* Filter: Optolong L-eXtreme
* Mount: Orion Sirius EQ-G
* Guide: William Optics 32mm; ZWO ASI 120MM Mini
* Software: PixInsight, Photoshop, Topaz DeNoise AI, Lightroom
* Control: ASIAIR PRO
* 840 x 120 seconds

Total integration time: 28 hours

By Lee Pullen

Example source data

This is what a single 120-second subframe looks like, debayered and with a simple stretch.
This is the integration of 840 x 120 seconds (28 hours) just with a simple stretch, before any proper editing.

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