Calling William Optics RedCat owners to take part in a unique astrophotography collaboration.

In April 2021 I did an image collaboration with an Astrophotographer I met on Twitter @astromatt75. Discovering we had an identical setup of telescope, camera and filter, we decided to photograph the same object and share our data sets so we each effectively doubled our data.

Together we managed around 5hrs on Markarian’s Chain and the images we produced were better than our individual attempts.

Taking this collaborative approach one step further, we now propose a Summer Challenge for WO RedCat users to photograph and share data on a new target: The Veil Nebula Complex in Cygnus. This target is perfectly situated for northern hemisphere observers and well suited to this scope’s wide 250mm focal length. Rather than just the two of us, we thought why not throw the invitation open to our other Astro friends, and anyone who wants to contribute? Maybe we could get 10 hours from 10 different astrophotographers? Or even 20hrs…

Please note this has no affiliation with WO or ZWO and is purely for fun, for amateurs like myself and Matt.

The Aim

The aim is to create a wonderfully detailed, colourful low-noise image by combining the efforts of as many contributors as possible using the same, commonly-paired equipment. The Veil Nebula Complex is a lovely bright target that is very obliging to amateur photographers shooting in colour with narrowband filters. As it’s summer and nights are short, collecting many hours takes real effort and dedication, so why not take just one hour but have the benefit of many hours effort? We can all try to process the shared data and compare the results - noting that this is not a processing competition.

How you chose to process the shared data is entirely up to you.

The Invitation

As a RedCat owner, you are invited to collect a minimum of 1 hour of data over the Summer of 2021 on The Veil Nebula Complex which you will share with all other contributors and then process the combined data yourself. By taking part you’d consent to your data being used by others and that the processed images would be credited as a collaborative effort by all. The period for collecting images will run from now (late June) to the end August 2021, after which the data will be made available to share.

Equipment list

Myself and @astromatt75 will be using this setup below, and we encourage you to use the same (if you have it) or as close as possible such that image processing software can handle any minor variations:

Telescope - William Optics RedCat 51 (or variants WhiteCat / SpaceCat), 250mm focal length at f/4.9.

Camera - ZWO ASI294MC Pro single shot cooled colour camera. This uses the Sony IMX294 sensor, produces images at 10.7 megapixels, 4144 x 2822 resolution at 4.63um pixel size.

Filter - Optolong L-eXtreme dual narrowband filter (7nm Ha & OIII). This type of filter should really make the Veil pop.

Mount - Your choice, but should be an equatorial mount that eliminates the Earth’s rotation and enables long duration subs.

Image Framing

We will all need to frame our images in the same orientation to match our data as closely as possible. Whether you use software for this, or just by eye, referencing the image below from the Sky Safari App, use star HD198626 as your central point with the bright 52 Cyg at 45deg to the right/ west. This will frame the three elements of The Veil Nebula Complex NGC 6992 (Eastern Veil), NGC 6960 (Western Veil) & NGC 6974 (Pickering’s Triangle) with enough margin for some cropping and misalignment tolerance.

Your Data Set

You’ll want your data to be easy for others to use without any need for conversion or complex manipulation. Please try to capture as close to these settings as possible:

• min. 1 hour of data using 120s subs, (so min. 30 x 120s Lights) in FITS format.

• on the ASI294 MC Pro, use settings Bin 1x1, Gain 120.

• select cooling to suit your conditions (I’ll be aiming for maybe -10deg or better).

• collect calibration frames at the same time/ temperature including (suggestion) 20x Darks at 120s (to match your Lights), 60x Bias, 30x Flats and if you can be bothered, 30x Dark Flats too.

Sharing Data

Once everyone has collected their images, we’ll need to share it with each other. You’ll need access to a Dropbox (or similar) where you can upload and then allow others to download using a link. We will each host out own data and will need to keep the link active for a few weeks. It will be a few GBs worth so bear this in mind. Try and organise everything neatly into folders for each image set; Lights, Darks, Flats, Bias and Dark Flats.

If you’d like to take part, please drop me an email or tweet and I will ensure everyone gets a list of all the download links when available. If you consent, I can always publish a list of links online too. Use this email: blt_astro@icloud.com

The Results updated Oct 2021

Below is a gallery of images produced with the data from the RC51SC collaborators. We had four astrophotographers from UK x2, California and Poland submit around 17hrs of data which was combined together in each image. Each used a RedCat51 with either a ZWO294MC Pro one shot colour camera, a ZWO1600 Mono or ZWO2600 Mono. We used a variety of mounts and peripherals including the Optolong L-eXtreme filter.

The contributors were: Myself @blt_astro, @astromatt75, @jtronson and @WojciechITB (all Twitter handles).

I will probably continue to tinker with these images as I’ve never had so much data to play with on one image before. It is such a dynamic object that had loads of fascinating imaging possibilities.

First of many?

Despite a poor summer for weather which delayed most of us until late Aug or early Sept, we achieved what I’d hoped - to capture far more good data together than we would each have had the time to do alone. I hope this will inspire others to collaborate with others with similar set-ups and that we can expand the team to do more RedCat51 collaborations in the future.