Solar Spectrum From Raheny.

Thought you guys might enjoy this. A full solar spectrum taken this morning at Raheny observatory, Dublin. Taken while a massive flare was kicking off. However as this was reflected sunlight the entire continuum is covered rather than just a discreet slit. The full visible spectrum takes four frames to cover with my C14 and ST8 CCD. This is the first serious image I have taken with my new L200 spectrograph (R=3000). I'm quite pleased with the result.

Anyway I've written it all up and commented the lines as much as my limited knowledge of this area allows. All line's are measured (rather than transcribed) line idents are done with vspec.exe.

Here's the link

www.webtreatz.com/index.php/articles/34-...es/78-solar-spectrum


Hope you enjoy.

Interesting Dave.

Would it be possible to insert a particular filter into the lightpath and measure how much light it blocks at each wavelength?
How accurate would the measurements be?
Presumably, the darker the filter, the longer the exposure?

Michael.

Michael, the easy way to test a filter would be to place it in front of the spectroscope and shine a source without absorption or emission lines. A smalol halogen bulb would be a good choice. You could then do a simple intensity profile to determine the transmissiveness at any given wavelength. The spectral resolution of the L200/ST8 of 0.75angstroms/pix binned 1x1 would be absolute overkill for an application like this.

You would also need to take into account the spectral response curve of the camera and any field curvature introduced by the optics. The former could be derived empiracally by imaging the continuum without a filter. The latter resolved using spectroscopic flats.

For example you could easily measure and verify the transmission width of a narrow band filter or such.

Great work Dave,

Everyone really enjoyed the little talk yesterday on the above subject. Well done again.

Nice work Dave!

Regarding Michael's question re light source.

I use both an Argon lamp and a Neon lamp for this process.

This provides a good test for resolving at sub angstrom resolution for your spectroscope.

Eamonn A