Spectral calibration by using low cost optical fibers
Posted: Fri Feb 04, 2022 4:23 pm
I'm developing the following precision spectral calibration :
(1) The spectral calibration flux is permanent at the entrance of the telescope/refractor or semi-permanent (low intensity miniature lamps or low cost plastic optical fibers (1.5 mm diameter, 25 euros for 100 meters - see Amazon - see photos + 3D print). So, these illumination is permanent (here neon lamp for calibrate Halpha region) during the exposures. The spectral lines do not saturate the exposed image.
(2) Each image therefore contains a mixture of the star spectrum and the calibration spectrum.
(3) processing (specINTI software for exemple) to precisely calibrate each image (compute the first order shifting, for exemple) and removal of calibration lines in the final profile.
Obstruction in the entrance pupil is negligible (less than 0.04 magnitude with a 100 mm diameter refractor). This new approach is effective in eliminating the effect of mechanical flexure (calibration error), economical and easy to made. Valuable for all spectrograph.
Christian Buil
Sol'Ex/Star'Ex web: http://www.astrosurf.com/solex/
Chaine YouTube Astro-Spectro: https://www.youtube.com/channel/UCdlVj1 ... g/featured
(1) The spectral calibration flux is permanent at the entrance of the telescope/refractor or semi-permanent (low intensity miniature lamps or low cost plastic optical fibers (1.5 mm diameter, 25 euros for 100 meters - see Amazon - see photos + 3D print). So, these illumination is permanent (here neon lamp for calibrate Halpha region) during the exposures. The spectral lines do not saturate the exposed image.
(2) Each image therefore contains a mixture of the star spectrum and the calibration spectrum.
(3) processing (specINTI software for exemple) to precisely calibrate each image (compute the first order shifting, for exemple) and removal of calibration lines in the final profile.
Obstruction in the entrance pupil is negligible (less than 0.04 magnitude with a 100 mm diameter refractor). This new approach is effective in eliminating the effect of mechanical flexure (calibration error), economical and easy to made. Valuable for all spectrograph.
Christian Buil
Sol'Ex/Star'Ex web: http://www.astrosurf.com/solex/
Chaine YouTube Astro-Spectro: https://www.youtube.com/channel/UCdlVj1 ... g/featured