Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Roberto on Feb 21, 2021, 10:35:15

Title: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: Roberto on Feb 21, 2021, 10:35:15
This one took a while to complete - from November to February.  The Jellyfish nebula at the feet of Castor.  Also shown is the blue reflection nebula van den Bergh 75 illuminated by 12 Geminorum.  IC444 is of dubious origin though as it does not seem to correspond to the index catalog object assigned to the coordinates.  The beautiful, bright, golden stars are Tejat Prior (Propus - a great double) and Tejat Posterior (Calx).

Details of acquisition can be found here:  https://www.astrobin.com/8qexuf/E/ (https://www.astrobin.com/8qexuf/E/)

Thanks

Roberto

(https://cdn.astrobin.com/thumbs/DFph7BTx_WJA_16536x0_85166Htd.jpg)
Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: RobertM on Feb 21, 2021, 14:40:58
Lovely image Roberto.

The triangle of the two yellow and the blue star contrast with and frame the nebulosity very well.

Robert



Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: Roberto on Feb 21, 2021, 15:28:13
Thank you Robert!
Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: Carole on Feb 21, 2021, 17:59:03
Very nice Roberto.

This is quite a large Nebula and needs a Mosaic which I presume you have done by the shape of the image.

Carole
Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: Roberto on Feb 21, 2021, 20:05:00
Hi Carole

Thank you!  Yes, it's a 2x1 mosaic - only way to fit it all in.  I could have made a 2x2 to include an open cluster to the right of vdB75, but only managed to complete these two panels over 3 months...

Roberto
Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: MarkS on Mar 16, 2021, 16:32:36
Wow - that is a great result!  An incredible 18 hours of data.

I like your subtle processing.  I imaged the same area this time last year and in comparison I feel my processing is rather harsh:  http://forum.orpington-astronomy.org.uk/index.php?topic=11960.0

Mark
Title: Re: IC443, vdB 75, IC444 - 2x1 mosaic at feet of Castor in Gemini - HaRGB
Post by: Roberto on Mar 16, 2021, 16:36:32
Thank you Mark.  The amount of OSC data helped smooth the background a bit.  I also used the star reduction technique of Adam Block (using PixInsight) which gives more prominence to the nebulae as the field is full of beautiful - but very bright - stars.

Roberto