The H a hydrogen emission line is spectacular. Exposure times of 30 seconds. Our homemade spectrograph can give access to galaxy spectra. Corresponding spectra are surrounded by an orange rectangle. They are pretty much similar to that of most stars.
North is to the right.
Thirty seven images of 120 seconds exposure have been composited, which is equivalent to an integrated exposure of 1 hour and 10 minutes. The wavelength measured for the emission line is 0.6740 micron. Atmospheric atomic oxygen's line at 0.76 microns is readily visible in the spectra for most stars. The Balmer lines are clearly visible in the blue part of the spectrum.