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The Bubble Nebula in Ha

steppenwolf

By steppenwolf
in Imaging - Deep Sky

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steppenwolf

steppenwolf

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The Bubble Nebula

The Bubble Nebula in the constellation Cassiopeia appears in several catalogues under the entries of NGC 7635, Sharpless 162 and Caldwell 11.  The bubble is an HII emission nebula created by the stellar wind generated by the super hot Wolf-Rayet star BD +602522 which is believed to be 4 million years old. This star is 45x more massive than our own Sun and its intense heat has ejected some of the star’s outer atmosphere into space where it is somewhat contained by a giant molecular cloud and it is the interaction of this cloud with the expanding gas that highlights the strong edge of the expanding bubble. Perhaps as much as 25% of the star’s atmosphere has been ejected.

Discovery

The nebula was discovered on 3rd November, 1787 by William Herschel from his Slough observatory where he described it as ‘A star of 9th magnitude with a very faint nebulosity of small extent about it’.

Location

Chart.thumb.png.6aad9d867c0c34f048790ad32902b2bc.png

Image Stats

Mount: Mesu 200
Telescope: Sky-Watcher Esprit 150
Flattener: Sky-Watcher Esprit specific
Camera: QSI 683 WSG-8
Filter: Astrodon 3nm Ha
Subframes: 24 x 1800 sec Ha
Integration: 12 hours
Control: CCD Commander
Capture: MaxIm DL
Calibration, Stacking and Deconvolution: PixInsight
Post-Processing: PhotoShop PS3

Ha Version

Bubble_Nebula_Ha.thumb.png.38313517169ab0c5ed726da5ff3c6fa1.png

Bi-colour Ha/OIII/OIII Version

My wife is always disappointed when I don't produce a 'colour' version so here is a down and dirty quick bi-colour version using the original Ha data with the addition of OIII data captured under very poor skies!

Ha_OIII_OIII_SGL.thumb.png.1a6cca6741c401207ff10ea54fa3dd0f.png

A Wider Context

The nearby star cluster M52 makes an excellent pairing if you have an imaging system with a wide field of view. To demonstrate this, the following is an image I took soon after I had started out in astrophotography so technically it isn't great but it does show the pairing well. M52 is in the bottom right hand corner.

Bubble_Nebula_M52_OSC.thumb.png.2ebe036607d8efd0c6c99d4e2d1f5e72.png

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Hallingskies

Hallingskies

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Nice Bubble!  It was my first proper target when I returned to the hobby last year.  You have done a great job of hiding the distracting sea of tiny stars that otherwise show up in the field.  It would be interesting to see your OIII stack - is there much in this object?

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alan4908

alan4908

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Very impressive Steve.

On the processing front, I see that you've moved to Pixinsight for the calibration, stacking and deconvolution. I could never get deconvolution to give good results in MaximDL although stacking and calibration seemed OK. 

Alan

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steppenwolf

steppenwolf

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6 hours ago, souls33k3r said:

Oh my! that is just grand imaging mate. Really impressed sir!

Thank you, it was fun doing it!

5 hours ago, ollypenrice said:

Very fine Bubble, Steve. It's a delightful target.

It is indeed an amazing object, Olly.

4 hours ago, swag72 said:

Lovely Bubble Steve - My favourite is the mono version..... that's sublime :) 

Thank you, Sara, the Ha version is certainly my favourite - there is so much going on.

4 hours ago, celestron8g8 said:

All three a very nice captures especially the WF with the GC ! 

Thank you, Ron.

4 hours ago, Z3roCool said:

Wow! That is truly beautiful :D  Great shot ?

Thank you, I'm pleased you like it.

3 hours ago, Demonperformer said:

Very nice, Steve.

Would agree with Sara that the mono is my favourite - the OIII doesn't seem to be adding a lot to it.

I absolutely agree, the OIII adds nothing special to this particular image except the opportunity to add false colour to keep the boss happy ?

3 hours ago, JimothyC said:

Well that's just stunning.

I'd like to think a little bit of the money I spent on your book went into creating that ?  Maybe one of the fainter stars in the bottom right hand corner....

Because you have been so nice, I'll donate that star to you for your own personal use .....

2 hours ago, daz said:

Two very nice images Steve!!

The bubble just seems to 'hang' in the surrounding gases! 

Like that lots!!!

Thanks, Daz those surrounding gases are in a way suspending the bubble - they're certainly constraining it as hard as they can.

2 hours ago, Hallingskies said:

Nice Bubble!  It was my first proper target when I returned to the hobby last year.  You have done a great job of hiding the distracting sea of tiny stars that otherwise show up in the field.  It would be interesting to see your OIII stack - is there much in this object?

The narrow bandwidth helps with the stars but I also spent some serious time with the deconvolution. You will be as disappointed as I was with the OIII as you will see in the comparison images that follow. This was 18 x 1800 sec exposures with my Astrodon 3nm OIII filter. Now it would be fair to say that conditions were not that great but I had expected more than this! Ha on the left, OIII on the right.

Ha_OIII_comparison.thumb.png.510a5d031441fbc48dac15ada9b16ca1.png

2 hours ago, AndyUK said:

Very nice indeed, Steve :icon_salut:.  (I too prefer the mono version, but my wife's the same - Whenever I've shown her a mono image, it barely gets a glance...!). 

Surely this must just be their 'ignorance', Andy but I promise not to tell yours if you keep schtum to mine! ?

1 hour ago, alan4908 said:

Very impressive Steve.

On the processing front, I see that you've moved to Pixinsight for the calibration, stacking and deconvolution. I could never get deconvolution to give good results in MaximDL although stacking and calibration seemed OK. 

Thanks, Alan, I did indeed use PI for the deconvolution. I make no secret of the fact that deconvolution and I do not always see eye to eye! Sometimes MaxIm DL would deconvolve for me and for other images it just wouldn't. To be honest, the same is true for PI - I have 3 hours of rather shabby SII data for this image captured with a wider bandwidth filter and I just can't get it to deconvolve in PI no matter what settings I use. Deconvolution remains a bit of a dark art to me but I am persevering. MaxIm DL calibrates and stacks very well indeed and I still use if I am not going to deconvolve - however, if I intend to deconvolve, I use PI for all three processes. In ALL cases though, I move onto PhotoShop as soon as I can! ?

12 minutes ago, PhotoGav said:

You have that Esprit singing Steve, lovely bubbly!

Thanks, Gav - I do love this Esprit, it is my weapon of choice these days.

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Hallingskies

Hallingskies

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2 hours ago, steppenwolf said:

Deconvolution remains a bit of a dark art to me but I am persevering.

Moot point I suspect, but I find Astroart to be a real boon for stacking, sub-set alignment and deconvolution. I’m no processing wiz but in most cases I find gentle application of either AA’s maximum entropy or Lucy-Richardson tools to be a useful and easy method for massaging stars that aren’t too bloated.

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steppenwolf

steppenwolf

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55 minutes ago, newbie alert said:

Deconvolution..is that just a pixinsight tool or can it be done in Photoshop etc?

Deconvolution is a process that is available in several processing packages and is carried out when the data is in a linear state (i.e. before 'stretching'). PhotoShop doesn't offer this facility, relying instead on sharpening tools.

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tomato

tomato

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Very nice Steve, super sharp right out to the edges of the frame, the 150 is certainly delivering. I do prefer the monochrome version, but having said that I have just purchased an OIII filter to add some colour to my NB imaging. True to form, it has yet to see any clear, moonless sky from North Yorkshire.

 

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steppenwolf

steppenwolf

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On 23/08/2018 at 20:30, smr said:

Stunning!

Thank you!

16 hours ago, Adreneline said:

The Bi-Colour version is amazing - beautifully done Steve.

Will there be a cross-stitch version to follow?

Adrian, I've asked the 'stitcher' and she says 'NO, not enough colour' - well there's a surprise then. You see, this is what I have to put up with at home ?

2 hours ago, tomato said:

Very nice Steve, super sharp right out to the edges of the frame, the 150 is certainly delivering. I do prefer the monochrome version, but having said that I have just purchased an OIII filter to add some colour to my NB imaging. True to form, it has yet to see any clear, moonless sky from North Yorkshire.

The Esprit 150 and 3nm Ha filter are working out very well for me when the sky allows but I often find that it is worthwhile capturing the OIII as well to produce a bi-colour but it just didn't work for me on this object. I am sure that you will find the OIII filter a really good addition to your imaging and there is something rather fun about bi-colour work as you really can put your own colours to the image.

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ollypenrice

ollypenrice

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I did this in RGB enhanced by NB recently and did find the OIII useful in that context.  It just brought a change in the reds towards the central part of the outlying nebula round the Bubble. There wasn't much to resolve in it though.

Olly

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steppenwolf

steppenwolf

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3 hours ago, ollypenrice said:

I did this in RGB enhanced by NB recently and did find the OIII useful in that context.  It just brought a change in the reds towards the central part of the outlying nebula round the Bubble. There wasn't much to resolve in it though. 

I concur! ?

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