The Wolf Nebula

[lazjen (Chris)]

Nothing much I can add other than I like it.

[jase (Jason)]

Nice one Greg! Its be interesting to see the different renditions of this target over the last couple of months. Paul's and Marcus' are the main ones I picked out. There are likely others. You've produced another splendid rendition. You've certainly been productive of late. Well done.

[madbadgalaxyman (Robert)]

The shell structure photographed by Greg appears to be just one section of an even much larger shell which extends a long way to the North.

However, the northern parts of the shell are not nearly as well behaved.....Very chaotic and complex in appearance.

A literature search for scientific papers since 1975 reveals that next to nothing is known about the origin and evolution and future of this vast H-alpha emitting shell, despite its extreme prominence in the southern Milky Way and despite the fact that the candidate energizing objects (NGC 6231, Scorpius OB1 association, plus the consequent core-collapse supernovae) seem to be obviously visible.

Here is the entire shell (in centre of image) from the SuperCOSMOS H-alpha survey.

[gregbradley]

Originally Posted by lazjen

Nothing much I can add other than I like it.

Thanks for that.

Originally Posted by jase

Nice one Greg! Its be interesting to see the different renditions of this target over the last couple of months. Paul's and Marcus' are the main ones I picked out. There are likely others. You've produced another splendid rendition. You've certainly been productive of late. Well done.

I found AAIC gave me a 2nd wind. I have a lot of images I haven't released yet. Some with the CDK17. These generally take a lot more processsing than the ones from the TEC110 which are easy.

Originally Posted by madbadgalaxyman

The shell structure photographed by Greg appears to be just one section of an even much larger shell which extends a long way to the North.

However, the northern parts of the shell are not nearly as well behaved.....Very chaotic and complex in appearance.

A literature search for scientific papers since 1975 reveals that next to nothing is known about the origin and evolution and future of this vast H-alpha emitting shell, despite its extreme prominence in the southern Milky Way and despite the fact that the candidate energizing objects (NGC 6231, Scorpius OB1 association, plus the consequent core-collapse supernovae) seem to be obviously visible.

Here is the entire shell (in centre of image) from the SuperCOSMOS H-alpha survey.

Attachment 148860

Fantastic Robert. I noticed this area doing my Ha of the Milky Way that there was a lot of Ha near NGC6188, which is here:

Greg.

[madbadgalaxyman (Robert)]

The Panther Observatory image of this region shows a plausible (arguable) outermost boundary for the overall giant shell of which Greg has photographed the most well-defined section.

http://panther-observatory.com

The overall shell might be oval in shape, but don't quote me on it.

Here I have taken Schedler's image, converted the H-alpha into some weird colour, and then made a negative, in order to show the hypothetical oval outline of the shell:



P.S.
(Added in edit) Regarding NGC 6188

The NGC 6188 identifier probably refers only to the brightest section of the Norma-Ara nebula. The entire 2-degree-scale HII region is known as RCW 108
(in the Rodgers and Campbell and Whiteoak catalog)(reference: 1960, MNRAS, Vol. 121, page 103)

The RCW is the primary nebular catalog between Ara and Crux, yet many star atlases still don't display RCW objects!!!!$%^&&*&*!!!

When I had the optimal visual sensitivity, in my 20s, I could trace this nebula for 1 and a half degrees, even just using the retinal detectors. (This nebula resembles a ghostly version of the Eta Carinae Neb.)

I will attach the RCW catalog in the science forum.

[gregbradley]

Originally Posted by madbadgalaxyman

The Panther Observatory image of this region shows a plausible (arguable) outermost boundary for the overall giant shell of which Greg has photographed the most well-defined section.

http://panther-observatory.com

The overall shell might be oval in shape, but don't quote me on it.

Here I have taken Schedler's image, converted the H-alpha into some weird colour, and then made a negative, in order to show the hypothetical oval outline of the shell:

Attachment 148890

P.S.
(Added in edit) Regarding NGC 6188

The NGC 6188 identifier probably refers only to the brightest section of the Norma-Ara nebula. The entire 2-degree-scale HII region is known as RCW 108
(in the Rodgers and Campbell and Whiteoak catalog)(reference: 1960, MNRAS, Vol. 121, page 103)

The RCW is the primary nebular catalog between Ara and Crux, yet many star atlases still don't display RCW objects!!!!$%^&&*&*!!!

When I had the optimal visual sensitivity, in my 20s, I could trace this nebula for 1 and a half degrees, even just using the retinal detectors. (This nebula resembles a ghostly version of the Eta Carinae Neb.)

I will attach the RCW catalog in the science forum.

Thanks for that Robert. Imaging that shell is something I have it on my list of things to do. I started to image it with a Pentax 300mm 67 lens. But couldn't locate it! The lens needed to be aligned a bit better with the go-to. Perhaps it would be a good target for the TEC110.

Greg.

[marco (Marco Lorenzi)]

Great image Greg! A lovely and rich of objects part of sky

Clear skies
Marco

[Shiraz (Ray)]

that certainly is a lovely image Greg - very pleasing to look at

[gregbradley]

Originally Posted by marco

Great image Greg! A lovely and rich of objects part of sky

Clear skies
Marco

Cheers Marco.

Originally Posted by Shiraz

that certainly is a lovely image Greg - very pleasing to look at

Thanks very much Ray.

Greg.

[madbadgalaxyman (Robert)]

Hello Greg and other H-alpha imagers,

the latest professional H-alpha survey of the southern Milky Way is called VPHAS+

It utilizes the 2.6 meter VLT Survey Telescope (the VST) together with the OmegaCAM array of CCDs ( http://www.eso.org/sci/facilities/pa...omegacam/inst/ ) , and it will survey much of the southern Milky Way:

http://www.vphasplus.org/

[[
VPHAS+ is the successor to the H-alpha survey that was done (on film!) with the UK Schmidt:
http://www-wfau.roe.ac.uk/sss/halpha/
]]

Some of the first H-alpha images from the new survey are probably available through the ESO data archive. They were made through the NB 659 filter, which is similar to an H-alpha filter :

http://archive.eso.org/wdb/wdb/adp/phase3_main/form

galaxyman's opinionated commentary :

Despite the use of a gigantic telescope, and perhaps because of the prohibitively large time and money expenditure that would be necessary to undertake the best ever survey of the Milky Way with a 2.6 meter telescope, VPHAS+ is far from being the ultimate H-alpha survey of the band of the Milky Way.....

(1)
Firstly, these Large Telescope H-alpha images are not going to be very deep images, though the angular resolution of the images is very good; 1 arcsecond or even better.
Apparently only 120 second exposures !!!....
In my view, this means that the survey won't be able to detect very faint nebular structures; It seems to me that even with a 100 inch telescope, such short exposures might not detect faint expanding supershells and faint Supernova Remnants.
Why on Earth use a giant telescope and then make shallow exposures??? (actually, the same criticism could be made about many Hubble Telescope exposures)

So I predict that the deepest H-alpha survey of the Milky Way is going to be done by an amateur astronomer.

(2)
Another deficiency of the VPHAS+ is that the survey fields do not stretch very far above the galactic equator (the apparent plane of our galaxy), so highly unusual and interesting structures high above the plane, such as those detected in Greg Bradley's very deep Milky Way exposures, will not be imaged in this survey.
Many of the least known and most interesting gaseous structures in spiral galaxies are well above the principal plane of a galaxy, e.g. gas being ejected from a galaxy and gas falling into a galaxy from its halo. Yet it is precisely these least understood H-alpha structures that won't be surveyed!

_________________________

[Paul Haese]

Urgh, Robert. It took enough time to image my image of this area. At 21 hours I have probably the deepest image of the object with 11 or 12 hours of Ha. Perhaps it might be prudent for a group of us to image the region in Ha and produce a combined survey. I am more than happy to contribute and participate in such a survey.

It goes to show that sometimes when you stubble on something and decide to image it for whatever reason; it may just be of interest to more than yourself.

[gregbradley]

Originally Posted by Paul Haese

Urgh, Robert. It took enough time to image my image of this area. At 21 hours I have probably the deepest image of the object with 11 or 12 hours of Ha. Perhaps it might be prudent for a group of us to image the region in Ha and produce a combined survey. I am more than happy to contribute and participate in such a survey.

It goes to show that sometimes when you stubble on something and decide to image it for whatever reason; it may just be of interest to more than yourself.

Definitely your image sparked off all this interest in what has been a relatively unimaged part of the Milky Way.

Looking at the widefield Ha images of this area there are some other objects of interest nearby. Like directly above on the 180mm lens shot you can see a brighter area of Ha with a bit of black dust and also diagonally off to the right there is another similar patch that may be worth imaging.

I think a mosaic would be great for this area. But its too late for this year probably or perhaps over 4 nights and 1 panel per night of 2.5 hours is all that is left for this year if you got 4 nights of clear weather.

galaxyman's opinionated commentary :

Despite the use of a gigantic telescope, and perhaps because of the prohibitively large time and money expenditure that would be necessary to undertake the best ever survey of the Milky Way with a 2.6 meter telescope, VPHAS+ is far from being the ultimate H-alpha survey of the band of the Milky Way.....

(1)
Firstly, these Large Telescope H-alpha images are not going to be very deep images, though the angular resolution of the images is very good; 1 arcsecond or even better.
Apparently only 120 second exposures !!!....
In my view, this means that the survey won't be able to detect very faint nebular structures; It seems to me that even with a 100 inch telescope, such short exposures might not detect faint expanding supershells and faint Supernova Remnants.
Why on Earth use a giant telescope and then make shallow exposures??? (actually, the same criticism could be made about many Hubble Telescope exposures)

So I predict that the deepest H-alpha survey of the Milky Way is going to be done by an amateur astronomer.

(2)
Another deficiency of the VPHAS+ is that the survey fields do not stretch very far above the galactic equator (the apparent plane of our galaxy), so highly unusual and interesting structures high above the plane, such as those detected in Greg Bradley's very deep Milky Way exposures, will not be imaged in this survey.
Many of the least known and most interesting gaseous structures in spiral galaxies are well above the principal plane of a galaxy, e.g. gas being ejected from a galaxy and gas falling into a galaxy from its halo. Yet it is precisely these least understood H-alpha structures that won't be surveyed!

_________________________[/QUOTE]

http://www.pbase.com/gregbradley/image/152449036 Closer up shot of the MW Wolf Nebula is top right corner area showing the broader shell of Ha

http://www.pbase.com/gregbradley/ima...95727/original most of the Milky Way Wolf Nebula is to the left side near the big loop RCW114
so you get oriented where this is overall.

That big loop of Ha is worth a mosaic. It doesn't show up in O111 unfortunately so that limits its beauty for a pretty picture.

Greg.

[DavidTrap (David)]

Nice image Greg.

Couple of queries - can you tame the cluster of stars in the widefield. I think they add to the overall image, but I find them distracting. Have they blown out in the long images required for the nebulosity? Would a HDR with some shorter images help?

Paul - your image has bigger halos around the bright stars. What do you think is the reason for this?? You're both using good quality glass to image??

Ta
DT

[gregbradley]

Originally Posted by DavidTrap

Nice image Greg.

Couple of queries - can you tame the cluster of stars in the widefield. I think they add to the overall image, but I find them distracting. Have they blown out in the long images required for the nebulosity? Would a HDR with some shorter images help?

Paul - your image has bigger halos around the bright stars. What do you think is the reason for this?? You're both using good quality glass to image??

Ta
DT

I did a minor repro on the image. I toned down the glob without losing its relative brightness and reduced the overall red look to the image.

Same links. I am happier with this version.

Greg.

[Paul Haese]

Originally Posted by DavidTrap

Paul - your image has bigger halos around the bright stars. What do you think is the reason for this?? You're both using good quality glass to image??

Ta
DT

Most likely the filters used and the f ratio. Mine is at f5.8 and I am using Astronomiks type II C. The Ha filter produces really large halos despite being replaced. I am about to change out my filters for Astrodons.

[Paul Haese]

I have also considered that it could be partly the imaging window on the QSI683. When I finish the current project I will find out the answer to that question.

[gregbradley]

Originally Posted by Paul Haese

I have also considered that it could be partly the imaging window on the QSI683. When I finish the current project I will find out the answer to that question.

Roland Christen posted something about that at one time he was using one.

Greg.

[David Fitz-Henr]

That's a great image Greg; nice colour processing! My imagination is only slightly better than madbadgalaxyman; I can see the wolf but not sure about the broken heart ...

[DavidTrap (David)]

Originally Posted by gregbradley

I did a minor repro on the image. I toned down the glob without losing its relative brightness and reduced the overall red look to the image.

Same links. I am happier with this version.

Greg.

I think it's better Greg, but the stars are all white - I was wondering if some shorter subs might give you back some star colour??

Originally Posted by Paul Haese

Most likely the filters used and the f ratio. Mine is at f5.8 and I am using Astronomiks type II C. The Ha filter produces really large halos despite being replaced. I am about to change out my filters for Astrodons.

Originally Posted by Paul Haese

I have also considered that it could be partly the imaging window on the QSI683. When I finish the current project I will find out the answer to that question.

I've never seen halos like that with my QSI583, Astrodons and my Tak. Hope it's not the imaging window - rather fond of my QSI...

DT

[madbadgalaxyman (Robert)]

Originally Posted by gregbradley

Definitely your image sparked off all this interest in what has been a relatively unimaged part of the Milky Way.

Looking at the widefield Ha images of this area there are some other objects of interest nearby. L

I think a mosaic would be great for this area.

http://www.pbase.com/gregbradley/image/152449036 Closer up shot of the MW Wolf Nebula is top right corner area showing the broader shell of Ha

Greg.

I think it worth mentioning that the pioneering original H-alpha imaging surveys and the consequent catalogs of HII regions that were produced from these surveys, for example Gum, Rodgers Campbell Whiteoak (RCW), Georgelin et al , do not even go as deep as your 180mm exposure!!

To me, the latest H-alpha shots by experienced imagers like yourself and Paul are a discovery machine.

There is so much diffuse Ha on your image that it is going to be difficult to distinguish individual objects from the Ha background, in ultra-deep Ha exposures!

Actually, the main scientific interest of deep amateur Ha imaging might be the detection of highly unusual Ionized Gas structures far above the plane of the Milky Way, like ultra-faint outflows and supergiant Ha shells.

cheers, Robert

Frankly, I am disappointed with the limited sky coverage and limited depth of the VPHAS+ survey. All that effort, for a partial coverage of the Milky Way plus limited depth......
Maybe amateurs can do better than this hurried project with a 100 inch telescope.