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View Full Version here: : Cometary Globules CG 30, CG 31 and CG 38 in Puppis


SkyViking
19-03-2014, 10:42 PM
Hi All,

I felt it was time to once again explore some of the lesser travelled paths in our Southern skies:
Here is my latest image with the new 12.5" f/4 scope, showing cometary Globules CG 30, CG 31 and CG 38 in Puppis.
These globules are very faint and they did take a reasonable amount of exposure (16 hours) to rein in even with this fast scope.

Link to high resolution image (4.2MB) (http://www.rolfolsenastrophotography.com/Astrophotography/Nebulae/i-W2Npd4z/X3)

About the image:
Pictured against the sprawling star fields and dark clouds of the Southern constellation Puppis are some ghostly glowing structures known as cometary globules. They owe their existence to complex interactions between gas and dust and the intense ultraviolet radiation from young O type stars in their neighbourhood. And possibly also to supernova explosions in the distant past.
Passing shock waves and radiation pressure have interacted with density fluctuations in the interstellar medium, and caused the formation of condensations called Bok globules. The radiation is also ionizing Hydrogen gas in the area, visible as the faint pink glow, while slowly eroding away the condensed globules and blowing their contents out into long tails, similar to that of a comet.
Radio observations from ESO's La Silla observatory in Chile have shown that the gas in the globules has a temperature of some 5,000 to 14,000 Kelvin.
Within the dense globules new stars are being born and at least one of these is visible as a bright orange glow in the dense upper right globule CG 30. This is a Herbig-Haro object (HH120); the result of plasma jets ejected from young protostars which collide with the surrounding gas and dust and cause the glowing emission.
These delicate light-year wide structures are relatively short lived and will ultimately succumb to the emerging radiation pressure from the very stars born within them. Within a few hundred thousand years a splendid cluster of young bright stars will emerge and take their place.
This particular region in the southern constellation of Puppis is very rich. Surrounding the globules are faint dark clouds and countless stars in all colours. The beautiful little blue reflection nebula on the left is Bran 106 / vdB-Ha 5.

Image details:
Date: 31st January and 2nd, 3rd, 25th, 27th February and 1st, 4th, 5th, 6th March 2014
Exposure: LRGB: 675:105:95:85 mins, total 16 hours @ -25C
Telescope: Homebuilt 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

Comments and critique is most welcome.

Regards,
Rolf

nebulosity.
20-03-2014, 07:36 AM
That is quite stunning Rolf :thumbsup:

What size FOV is this?

Cheers
Jo

gregbradley
20-03-2014, 08:35 AM
What a wonderful image. A very pretty field and an area I have not seen imaged before. A great capture.

The star colours look terrific.

Greg.

strongmanmike
20-03-2014, 01:27 PM
Yeah, great result on a very faint area Rolf, great target for your new Palomar scope too :D It probably looks a bit noisy to some but this aspect doesn't detract much from the view IMO I can still appreciate it as a deep and atractive image :love: of a faint dusty region :thumbsup:

Mike

alpal
20-03-2014, 02:15 PM
Hi Rolf,
Top image.
It compares well with this one from the giant Subaru 8.2m telescope:

http://www.robgendlerastropics.com/CG-30-Subaru-DSS-LL.html

cheers
Allan

sjastro
20-03-2014, 02:24 PM
Very nice Rolf.

Regards

Steven

atalas
20-03-2014, 05:02 PM
Awesome work Rolf!

Paul Haese
20-03-2014, 11:02 PM
Nice and unique view Rolf. Colours are lovely and I really like the composition.

mithrandir
20-03-2014, 11:35 PM
I made up a blinking GIF comparison of Rolf's and the Subaru image. It's too big to load in IIS but a somewhat reduced size images is here -> http://1drv.ms/1hGjUqI
You need to do a "View Original" to get it to blink.

alpal
21-03-2014, 01:08 AM
That looks great.
I used this link to go straight to it:

https://public.by3301.livefilestore.com/y2p4CDt9iyrZYllKCnnnJOaaE9o2wmw6qob 25Oy1mE36zRw3BoonbLbY2n65zBiy6aBaht g20w2_9e-BNgHD0kiFKHUNh-_jwAwr03jgBd2Qhk/CG_30-31-38.gif?psid=1

The dark areas seem totally different - (right in the middle.)
I wonder why that is?


cheers
Allan

SkyViking
21-03-2014, 09:09 AM
Thank you Jo, this FOV is approximately 48' x 36'.


Thanks Greg, cometary globules are fascinating and rather beautiful with their drawn out wisps of material. There seems to be a concentration of them in this area.
I do take particular care with star colours, so I'm glad you noticed that :)


Thanks very much Mike. Certainly if you zoom in on the original size there is noise in the darker areas. As you know, I don't mind that since I dislike the 'processed' look that is often the signature of excessive noise reduction. :)


Thank you Allan, yes I saw that one last year. As you pointed out there are some differences, which I presume are due to different filters used and perhaps processing? The mottled look of the central dark globule was completely absent in my data, maybe it only shows up in Ha :shrug:


Thank you Steven :)


Thanks very much Louie :)


Thanks a lot Paul, re composition I did actually consider including more of the bottom extensions but on the other hand the intensely red (carbon?) star at the top is also a nice touch, so I decided on this FOV in the end.


Thank you Andrew, that is a nice comparison. Interesting that my image seems to show more background details but the globule features vary slightly. Perhaps due to different filters I presume.

Leonardo70
23-03-2014, 09:59 PM
Congrats Rolf ... what a wonderful image.

All the best,
Leo

SkyViking
25-03-2014, 07:56 AM
Thank you very much Leo, I'm glad you enjoyed it. It is a very interesting area of the sky and not often imaged.

multiweb
25-03-2014, 07:58 AM
Wow!. That's a beautiful shot Rolf. Gotta be stoked with that new toy of yours. :thumbsup:

bratislav
25-03-2014, 01:48 PM
Another outstanding image, Rolf! Really nice to see some new stuff, and done so well.

RickS
25-03-2014, 10:04 PM
Lovely image, Rolf!

Stevec35
26-03-2014, 09:47 AM
Terrific image as usual Rolf! I envy the clear skies you must be getting. It ain't happening here.

Cheers

Steve

SkyViking
27-03-2014, 10:33 AM
Thanks very much Marc, yes the scope is performing beautifully. No issues at all, and the Ovision worm upgrade really helped.


Thanks you Bratislav, it's not an often visited patch of sky for sure :)


Thank you Rick! :)


Thank you Steve, it has been a bit patchy lately, with mostly clear skies but the odd little cloud coming in to upset my guiding... I hope it clears completely soon :thumbsup:

astronobob
29-03-2014, 02:00 AM
Quite a WizzBang view there, strong colours and a great look :thumbsup:

SkyViking
03-04-2014, 08:45 PM
Thanks Bob, I like colourful scenes and the somewhat mystic atmosphere of this one made it a bit special I reckon :)