All-new M45 Widefield.

[ollypenrice]

Another RASA project with Paul Kummer.  We shot a wide M45 mosaic last season in the RASA but it was done before we'd found the best front end cable routing and this compromised the star shapes. We are doing a mosaic right over to the California but Paul felt we ought to re-shoot the Pleiades rather than stick with the rather rough first version. Good decision, this is much better. Paul did the capture and assembled the linear mosaic in APP. The post processing is mine, mostly in Photoshop and using StarXterminator for star control.

Olly

 

Edited December 4, 2022 by ollypenrice
False click

[scotty38]

Very nice and some fine processing there!

[Sunshine]

An EPIC M45! wow, nothing like waking up this sunday morning to some fantastic images, I don't see many M45 in such wide a field and this is marvellous!

[geoflewis]

Simply gorgeous 

[Alien 13]

M45 looks majestic in wide field, love the spattering of the blue stars in the FOV too.

Alan 

[ollypenrice]

22 hours ago, scotty38 said:

Very nice and some fine processing there!

Processing was interesting.  I followed my usual routines in working on the starless image and got a result I liked very much. I then tried to extract the stars from the regular image and replace them, but they looked awful. I've used this method on at least 20 images without difficulty. A bit stuck, I tried placing the highly stretched starless image over the standard image which I'd stretched only till the stars were nice but the rest was still dark. I then changed to blend mode Screen and, with a little work in Curves for the bottom layer, I ended up with what you see. I really thought I was going to have to go back to stage one, but no.

Olly

[scotty38]

1 hour ago, ollypenrice said:

Processing was interesting.  I followed my usual routines in working on the starless image and got a result I liked very much. I then tried to extract the stars from the regular image and replace them, but they looked awful. I've used this method on at least 20 images without difficulty. A bit stuck, I tried placing the highly stretched starless image over the standard image which I'd stretched only till the stars were nice but the rest was still dark. I then changed to blend mode Screen and, with a little work in Curves for the bottom layer, I ended up with what you see. I really thought I was going to have to go back to stage one, but no.

Olly

Well it definitely worked and I did not realise there was so much more to this target, great work!

[clarkpm4242]

Beautiful @ollypenrice!  What is the exposure info?   I am keen to redo M45 with my RASA 8/ ASI2600 combo.  Thank you.  Paul 

[ollypenrice]

1 hour ago, clarkpm4242 said:

Beautiful @ollypenrice!  What is the exposure info?   I am keen to redo M45 with my RASA 8/ ASI2600 combo.  Thank you.  Paul 

Thanks Paul. This mosaic is based on a target of 3 hours per panel in 3 min subs. Naturally you do get panels which have more scrappers than others. Note that I live at a seriously dark site, SQM 22 on the very best nights. Regarding the main cluster, which I've shot many times in other rigs, I've never had so much control over the brightest stars, despite the speed of the system. I also think that these captures found the best ERE (extended red emission) of any attempt I've made on M45. Shoot away: you have the technology! 

Olly

[old_eyes]

Very nice indeed @ollypenrice. I particularly like how the widefield puts the cluster in context. I have shown many people M45 images who assume that the nebulosity is part of the cluster - "is that the gas the stars formed from?".  This image really shows M45 is illuminating the gas and dust. A candle on a foggy night!

[ollypenrice]

2 hours ago, old_eyes said:

Very nice indeed @ollypenrice. I particularly like how the widefield puts the cluster in context. I have shown many people M45 images who assume that the nebulosity is part of the cluster - "is that the gas the stars formed from?".  This image really shows M45 is illuminating the gas and dust. A candle on a foggy night!

I remember seeing an image, I think in infra-red, years ago which confirmed that the cluster was moving through a dusty region rather than being surrounded by its progenitor gasses. What I particularly like in deep M45s is the clearly visible 'wake' created by the cluster's motion.

Olly

[AKB]

On 04/12/2022 at 15:26, ollypenrice said:

before we'd found the best front end cable routing

Any "best practice" advice available on this?  I've gone as far as a semi-circular route with the power and USB cables going down opposite arcs to keep the diameter of the obstruction as low as possible.  Anything further to consider?

Great image, of course!

Tony

[ollypenrice]

22 minutes ago, AKB said:

Any "best practice" advice available on this?  I've gone as far as a semi-circular route with the power and USB cables going down opposite arcs to keep the diameter of the obstruction as low as possible.  Anything further to consider?

Great image, of course!

Tony

Thanks Tony. It sounds as if we've followed the same path:

Note the bit of black tape near the power lead on the camera. This blocks a small light which created a reflection heading down onto the chip from the cable!

Olly

[AKB]

Thanks Olly.  Yes, lights on cameras, who would have thought?  I think that some these days allow you to turn them off with a 'stealth' mode.  Less of an issue, in general,  when you put them at the other end of the scope.

[ollypenrice]

1 hour ago, AKB said:

Thanks Olly.  Yes, lights on cameras, who would have thought?  I think that some these days allow you to turn them off with a 'stealth' mode.  Less of an issue, in general,  when you put them at the other end of the scope.

Hosting six telescopes, all with their own dedicated astro-specific accessories, has taught me that the designers of these products must all be natives of Las Vegas. Before I went round with the black tape the site was ablaze with lights of many colors, flashing (at various rates) or permanently ablaze. They really don't get it!

lly

[old_eyes]

6 hours ago, ollypenrice said:

I remember seeing an image, I think in infra-red, years ago which confirmed that the cluster was moving through a dusty region rather than being surrounded by its progenitor gasses. What I particularly like in deep M45s is the clearly visible 'wake' created by the cluster's motion.

Olly

Might it have been this Hubble image? Ghostly Reflections in the Pleiades (hubblesite.org)

This shows gas and dust around Merope, but 'ahead' of the star. Radiation pressure is supposed to be affecting different particle sizes differentially, slowing down the smaller particles more and stretching out the nebula in the lines we see pointing away from the star.

I see the 'wake' effect in your image streaming behind the cluster, but I am always cautious about our human tendency to see what we believe makes sense. We are just too damn good at pattern recognition. Could the nebula have been sculpted by some other process? I would be really interested to know.