ASTRO: Splitting the 658.4 [NII] line from the 656.4 Halpha line
the Custom Scientific 3nm FWHM filters were confirmed tonight to split the
very close emission lines of the [NII] doublet at 658.4 nm and the Halpha
line at 656.4 nm.
I used the 450mm f/12.6 classical cassegrain with the Lumicon GEG reducer in
the rearmost position for an effective focal ratio of f/7.1
Exposures were 20 minutes binned 2x2 using the FLI Maxcam10 at 3366mm focal
length (0.84 arc-sec/pixel)
It is clear that the filters will in fact separate those two very closely
spaced emission lines.
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