Sirius, α CMa, Spectral class A1

As is well known, Sirius is the brightest star in the night sky at magnitude -1.37. Hence it’s spectrum can be photographed with short exposures.

The first image that I show here was done in positive spectral orders (spanning +1 and +2) so is mainly of low dispersion. With my spectrograph, positive orders have longer wavelengths on the left and shorter on the right but I have standardised by displaying the image in the opposite order. Hence, I have reversed them in Photoshop by rotating 180 degrees.