filter and M76

by Richard Crisp


Finally I was able to shoot a tricolor image using my new Cust Sci [NII] filter.

I shot M76 using [SII], [NII] and [OIII]. The weather has been challenging for this project, but over two nights I did get three shots through each of the three filters. The individual exposures were 45 minutes each.

The shot still shows more graininess than I would like, more exposure time being necessary to address it.

Still it is interesting nonetheless. I did get a bit of the outer wings that are often missed. Unfortunately the narrowband filters really whack the stars though. They are hardly recognizeable as such within the nebula.

I used the C14 at approximately f/12.46 with the Dream Machine, AO7, beam splitter etc.

The new image is the third one on the page:

http://www.rdcrisp.darkhorizons.org/m76_emission_lines_page.htm

or the direct link:

http://www.rdcrisp.darkhorizons.org/images/M76_s2_N2_O3.jpg

I did not do any localized editing, just did a bit of deconvolution, ddp and curve stretching with a bit of median filtering and unsharp masking. When I get more data, I will do the full treatment to it, but for now it is more in the raw state.

I hope to take some Ha data to compare with the [NII] data. The emission lines are so close together it will be interesting to see the differences if any. Ha is at 656.3nm while this [NII] line is at 658.3nm. The 3nm FWHM Cust Sci filters should be able to separate these lines in theory. It will be interesting to see if they really do in practice.

Best wishes to all and here's hoping for clear skies!