Clear night tonight with moonlight not a huge influence. I took another low-res spectrum of Eta Car using Canon 650D, 200mm lens and SA100 grating, stacking 27 exposures.
There is something that seems quite unusual with it - the camera seems to be picking up a response in the 350-400nm range where nothing is visible in the four other spectra I've taken, using the same settings & exposures. In fact, I can't find any spectra taken with this set-up that show any significant response in this wavelength region.
Got me perplexed. The hi-res spectra campaign for this object is concentrated on the 460nm upwards region. Any ideas or suggestions?
I've attached a reduced-size image but the full size is at the following link - click to enlarge if necessary. My spectrum from tonight is the lower one, with the spectrum from 28 July at top.
http://i727.photobucket.com/albums/w...l.jpg~original
Cheers -