Higher Resolution Solar Spectrum 
with 600 lpmm grating and new spectrograph 
Uploaded 3/23/14

This pair of images illustrates the increase in resolution (about 4 Angstroms FWHM) with the 600 lpmm grating installed. It took 9 frames to fully cover the spectrum from UV to IR. The color images were taken with our brand new DBK41 camera from Imaging Source, and shows the spectral lines against a stunning backdrop of the colors of the rainbow.

The image on the left was taken through a Baader IR/UV blocking filter, which constrains the range from about 400 to 700nm which is the range that the eye can see. The image on the right I've extended the range on both ends by removing the blocking filter and recording the near UV and the IR to 900nm in the IR. As you can see, the color camera has a peculiar response to IR. This is due to the leakage of IR in the different Bayer mask filters over the chip that produce the normal colors.

Click on the largest images to see all the lines, many of them are very narrow and you can pan back and forth with the scroll bars on your browser to see the whole length!

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I've marked the primary absorption lines here, there are hundreds of them across the spectrum marking the traces of elements in the Suns outermost atmosphere. Two versions are shown. the bottom of the spectrum is the raw data constructed from six sections right out of the spectrograph. The upper section has been cleaned up using a standard technique used by spectroscopists and more clearly shows many of the faint bands in the spectrum.

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A total of 9 panel were exposed and combined very carefully to produce this set. The normal visual spectrum is on the bottom. The two extended spectrums on the top are what additional wavelengths you get when you remove the Baader IR/UV blocker and are beyond normal visual range. In the UV on the left, you can faintly see the Calcium K and H lines on the extreme left end. On the right IR extension, the super dark bands are from Oxygen in Earths atmosphere being superimposed on the Suns spectrum. They are very detailed and complex! On the right side I ended around 900nm because the spectrograph tilt mechanism bottomed out. The spectrum gets very dim out there.