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View Full Version here: : Homunculus Nebula with ejecta (now Sidonio'ed a 2nd time!)


SkyViking
06-03-2011, 09:38 PM
Hi everybody, I've not been as active lately since I'm mostly waiting to purchase a larger CCD cam later in the year. However I always wanted to capture the faint ejecta around Eta Carinae and the Humunculus Nebula, since I didn't get it in my previous effort back in 2010 (see http://www.iceinspace.com.au/forum/showthread.php?t=56087), and thought this must be a good challenge for the ToUCam.
The difficulty in capturing this part of the nebula lies in overwhelming glare from Eta itself which drowns out the ejecta since it is so close to the star.

Image is available here: http://upload.pbase.com/rolfolsen/image/132966741/original

This time I tried taking longer subs with the 5x Powermate (@ f/25) but the results were just too blurry at that focal length and long exposure times. I then resorted to prime focus (wish I had a 2x Powermate...) and got a decent view of the ejecta which is visible around the Homunculus in the image.
There is a noticable colour difference between the Homunculus and the ejecta, with the ejecta having a much redder hue.

I blended my previous Homunculus image taken af f/25 over the new one of the ejecta to get a complete view of the fascinating structures in the area, hence the obvious difference in resolution. In the background are faint traces of the much larger Keyhole Nebula, especially to the upper right.

Hope you enjoy! :)

UPDATE: I have now, thanks to Mr. Sidonio's kind suggestions, managed to dig out some old data with longer exposure time and indeed found some further traces of the ejecta which I have blended into the image. The caption under the image is now updated to include all the 6 layers of varying exposure time that make up the image.

Mighty_oz
06-03-2011, 09:49 PM
Amazing stuff u do there :) Can't imagine what your going to be like when u get that new camera.

Octane
06-03-2011, 09:54 PM
Rolf,

Incredible. So inspiring.

H

strongmanmike
06-03-2011, 10:25 PM
Looks cool Rolf but I'm not sure your latest data really adds to the original high res shot of the lobes..? There is a lot more ejecta around the Homunculus than the new data shows :shrug: looks like you just need more exposure.

Your original essay montage is excellent :thumbsup:.

Mike

John Hothersall
07-03-2011, 12:48 AM
That shorter fl has given you really fine detail, stars suffer a bit but they are not important, colour is about right and redness of ejecta you captured is quite startling. Eta C is so bright it does drown out a bit but you controlled it pretty well with chosen exposures.

John.

Dennis
07-03-2011, 06:44 AM
Hi Rolf

Some really nice work on such a difficult object – well done! You have a knack for digging out the difficult stuff and producing these remarkable images with such basic equipment. I also like how you present the results with the comprehensive descriptions. In a word – inspirational!

Cheers

Dennis

jjjnettie
07-03-2011, 08:27 AM
You've done good Rolf. :D
All that detail!

SkyViking
07-03-2011, 10:56 AM
Thank you, I look forward to it too but I'm sure it'll be a bit of a learning curve! :)


Thank you H, glad you liked it.


Thanks Mike, I was aware of the large amounts of ejecta there but couldn't detect it in my raw shots other than the brightest arc. However, upon reflecting on your comment I dug down a bit further and streched one of my longer exposures to the very limit. One that at first glance didn't show anything of interest - and there it was :D
Definitely no easy task due to Eta's glare but I was able to squeeze a bit extra out so that the ejecta is now visible all the way around, in quite good agreement with the famous ESO images that have shown this earlier.
Image is now updated with the new version. Thanks again Mike :)


Thank you John, yes the key to this one is to combine multiple images of varying exposure. Thats what I did for the Homunculus itself originally, otherwise I couldn't have got any detail in the core at all, and now I also had to do it for the ejecta but it's definitely worth it.


Thanks Dennis :) I think a proper CCD camera would be better suited to this object, especially regarding the ejecta. But the Homunculus itself absolutely benefits from the many short exposures a webcam can capture. In this case it's very similar to planetary imaging.


Thank you JJJ, glad you enjoyed it :)

iceman
07-03-2011, 11:08 AM
Amazing image, so great!

astroron
07-03-2011, 11:22 AM
Great Pic , I love these latest High Res pics of the Homunculus:thumbsup:

von Tom
07-03-2011, 12:38 PM
Fantastic detail - well done Rolf!

gregbradley
08-03-2011, 04:47 PM
That's a ripper. Well done.

Greg.

jjjnettie
08-03-2011, 04:55 PM
:D Even Betterer!

DavidU
08-03-2011, 04:59 PM
Your awesomeness is showing.:thumbsup:

SkyViking
10-03-2011, 10:23 PM
Thank you all for your nice and ecouraging comments :)
It's great fun to be able to image these extreme objects and share the results with you here.

Octane
10-03-2011, 10:49 PM
Rolf,

Is it a processing artifact, are my eyes deceiving me, or is there a tertiary shell visible in your image?

I took the liberty of examining the red channel where it shows up quite prominently and have attached a crop with a stroke around what caught my eye.

Fabulous image, mate.

H

ballaratdragons
10-03-2011, 11:25 PM
Absolutely fantastic result Rolf!!!!

The detail in the Humunculous is amazing. :thumbsup:

Toucam's Rock ;)

strongmanmike
10-03-2011, 11:29 PM
Yep, there sure is (http://www.pbase.com/strongmanmike2002/image/131992798/original)Humi and then some :thumbsup:

Amazing what a web cam can pick up Rolf :eyepop:

Mike

JD2439975
11-03-2011, 03:24 AM
Pushing the envelope once again Rolf & with spectacular results.

Gold star & an elephant stamp for that effort. :thumbsup:

gregbradley
11-03-2011, 07:31 AM
That's an amazing result. Fabulous.

Greg.

SkyViking
11-03-2011, 09:58 PM
Thanks H :) And thanks for taking the time to investigate. I hadn't thought of checking the red channel, but I can see clearly what you mean.
Yes it might be a glimpse of the tertiary shell which indeed does exist. I can't say for sure however if it's not just the remnant of the glare from Eta (which did show prominently in the raw images). It still has to be said that a lot of processing has gone into this image so these tiny subtleties could be real or not. But it does correspond roughly to the extent of the tertiary shell, so maybe... :D


Thank you very much Ken. Yes, TouCams are surprisingly good, I'm glad I modded mine back then 8 years ago :lol::eyepop:


Thank you for confirming Mike, yes it really does looke like it. I'll get some more data some day and then maybe it'll show up better. In either case I can't be unhappy with 2 out of 3 shells though :lol:


Thank you Justin :) It's nice to be able to do these things even with such a basic camera. Such small and bright targets are where webcams have their force.


Thanks a lot Greg :)