Homunculus Nebula with ejecta (now Sidonio'ed a 2nd time!)
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/s...ad.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.
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.
Last edited by SkyViking; 07-03-2011 at 04:15 PM.
Reason: Improved image
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 looks like you just need more exposure.
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.
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!
Amazing stuff u do there Can't imagine what your going to be like when u get that new camera.
Thank you, I look forward to it too but I'm sure it'll be a bit of a learning curve!
Quote:
Originally Posted by Octane
Rolf,
Incredible. So inspiring.
H
Thank you H, glad you liked it.
Quote:
Originally Posted by strongmanmike
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 looks like you just need more exposure.
Your original essay montage is excellent .
Mike
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
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
Quote:
Originally Posted by John Hothersall
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.
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.
Quote:
Originally Posted by Dennis
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
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.
Homunculus Nebula with ejecta (now Sidonio'ed a 2nd time!)
looks like you just need more exposure.
.
