I still have had little luck finding Ultraviolet images that are easily comparable with yours.
However, here is a preview of a Hubble Space Telescope image of the Orion Nebula that I just downloaded from hla.stsci.edu(the Hubble Legacy Archive), which was taken at similar wavelengths to your image.
This Hubble image is a composite of an F439W filter image (this filter is similar to the standard Johnson B ("blue") filter) and another image taken with the F336W filter (which is very roughly similar to a U filter image)
Both images were taken with the HST and its WFPC2 instrument. The Principal Investigator of the program in which these images were taken was Beckwith, and the Proposal ID is 8894.
(I have not displayed only the UV image, as it is very ratty indeed)
I agree with Ken's comment that you are "boldly going" (!!)
There are always a few individuals who will be in the lead, while the others, like sheep, just go on doing what everybody else is doing.
What a great effort and result Steven
I particularly noticed the complete absence of the multitude of young stars that appear in IR images of this region. That's to be expected of course, but it's still a fascinating contrast if you compare for example with my recent NIR image of M42 here: http://www.iceinspace.com.au/forum/s...orion+infrared
Your UV version almost looks like a 'starless' rendition in comparison. It really highlights the difference in wavelength that these features are emitting.
I'm thinking it would be pretty cool to create an animation of M42 images, showing the transition through the spectrum from UV to IR.
Rolf,
The young O-B stars in the Trapezium and close by are the "powerhouse" which illuminates the M42 gas cloud.....
A lot of the other stars around them are severely dimmed due to the interstellar dust and reddened into the NIR.
I agree, an animation moving across the spectrum would be a very neat project!
What a great effort and result Steven
I particularly noticed the complete absence of the multitude of young stars that appear in IR images of this region. That's to be expected of course, but it's still a fascinating contrast if you compare for example with my recent NIR image of M42 here: http://www.iceinspace.com.au/forum/s...orion+infrared
Your UV version almost looks like a 'starless' rendition in comparison. It really highlights the difference in wavelength that these features are emitting.
I'm thinking it would be pretty cool to create an animation of M42 images, showing the transition through the spectrum from UV to IR.
Rolf,
That is an excellent image
An animation would be a great idea.
The enhancement of the dust regions in M43 in the UV image is very apparent when compared to your image.
Ken (Merlin66) raised the issue of significant red light leakage reported in UV pass filters. Red light leakage would result in H-Alpha contamination of the M42 image there by making it "not strictly" a UV image.
I am currently taking RGB images of M42. The M42 R images in the nebular regions indicated my ST-X10ME imaging at about 40-50% of full well capacity.
I decided to image a red LED using red and UV pass filters. The red LED has a frequency range of 610-760 nm which conveniently includes the H-Alpha emission at 656nm.
The exposure was adjusted to aim for a 40-50% of full well capacity with the red filter. The ADU counts for both red and UV filters was recorded.
The results and LED images are in the attachment.
The conclusion is while there is red leakage in the UV pass filter, the ADU count is so low that it would be difficult to distinguish this from the statistical and readout an noise in an image, and therefore the H-Alpha contribution is probably lost in the overall noise of the UV image.
We are getting some very interesting long and short wavelength images, thanks to Steven and Rolf.
I was surprised & amazed by how many extra stars Rolf's infrared image of the Orion nebula "dug out" from the dusty obscuring material in the nebula.
In contrast, the very short wavelengths block the background light from coming through the dust (by means of enhanced processes of scattering and absorption by dust grains), so we see the dark patches enhanced in Steven's near-ultraviolet image.
(UV imaging is good for detecting backlit dusty Protoplanetary Disks, for instance, at least if you have the angular resolution to image them.....)
This is very interesting Steven
I decided to hava a similar attempt at this.
I took 4 180 sec frames of the M42 region through an Astrodon U filter and simultaneously took a spectra of the region.
There is certainly lots of emission in the UV. The filter passes between about 3600 and 4000A. There are significant emission in this region as you an see from the spectra. There is emission at H delta and H ep plus there is a broad emission around 3720 that I'm not sure what it is. My spectrograph isn't very accurate in the UV so the measurement might not bee terribly accurate.
Interesting never the less.
Cheers
