NGC 2244 Open Cluster in the Rosette Nebula

[Trev S]

Attached is my attempt at imaging NGC2244, the open star cluster in NGC2237, the Rosette Nebula in the constellation Monoceros. NGC2244 is visually uninspiring, but it consists of several K-class giants.

The brightest star in the direction of the cluster is 12 Monocerotis, a K-class giant. The two brightest members of the cluster are HD 46223 of spectral class O4V, 400,000 times brighter than the Sun, and approximately 50 times more massive, and HD 46150, whose spectral type is O5V, has a luminosity 450,000 time larger than that of our star, and is up to 60 times more massive than the Sun, but it may actually be a double star.

Imaged on the night 5th January 2026 from my back garden in Surrey

9.25 SCT with 0.63x flattener reducer

ZWO ASi1600-MM cooled to -10C

AZEQ6GT mount

Antlia filters

Ha (red) 10x300s

Sii (green) 10x300s

Oiii (blue) 10*300s

RGB (stars) 10*10s

SGPro for mount/camera control 

PHD2 guiding

PixInsight and PS2 processing

Thanks for looking

[drja...@aol.com]

Hi Trevor

That is a first rate image.  Huge amount and sharp detail, not least the Leaping Leopard at 9 o'clock, which has come out very clearly indeed in your processing.  Your 9.25" is an ideal telescope for getting in that close and capturing the narrowband data.

The stars in the cluster are truly behemoths at up to 450,000 times the Sun's luminosity.

Are you using any of the Russell Croman Exterminator processes in Pixinsight, eg Blur Exterminator?   I'd be interested to know what you think of them if you are.  They are constantly being hyped up by astro influencers but there's a plausible undercurrent that they only work well if you have excellent data to begin with. 

Well done getting the data with the recent weather.

I will add the Rosette to my list for the Dwarf.  

regards

James

Sent from my iPad

On 14 Jan 2026, at 17:25, Trev S <trevs...@gmail.com> wrote:



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[trevsie7]

Hi James, thanks for the kind comments. I don't use the RC-astro tools as the cost put me off. Instead I use the SetiAstro tools Cosmic Clarity. The Denoise one works very well though the Darkstar (star removal) one isn't quite as good ye, but they are currently free and still being developed, so should only get better in time

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[Kevin Phillips]

Very nice, beautiful. Live the detail and focus is spot on. Great job Trevor.

Sent from Outlook for Android

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From: 'drja...@aol.com' via croydonastro <croydo...@googlegroups.com>
Sent: Thursday, January 15, 2026 8:07:22 AM
To: croydo...@googlegroups.com <croydo...@googlegroups.com>
Subject: Re: [croydonastro - 8169] NGC 2244 Open Cluster in the Rosette Nebula

 

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[Tim Coskun]

Hi Trev

I think James and Kevin have said it all - that's a super image and one to be proud of.

The Rosette is a great target both from widefield and close up perspectives and broadband/narrowband too, so lots of scope (pardon the pun) for more images!

I've been imaging the Pacman Nebula through December, but more of that in due course...

Best wishes

Tim C

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From: croydo...@googlegroups.com <croydo...@googlegroups.com> on behalf of Kevin Phillips <Thewelsha...@hotmail.com>
Sent: Thursday, January 15, 2026 10:04 AM
To: croydo...@googlegroups.com <croydo...@googlegroups.com>
Subject: Re: [croydonastro - 8171] NGC 2244 Open Cluster in the Rosette Nebula

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