This is linked from Solar System Graphics, which introduces the subject and shows how to use SatGraph. This node discusses SatGraph and technical aspects for anyone interested. The code can be accessed from the various sections discussed below but the actual Visual Basic source code may be harder to obtain.»
This describes a Visual Basic program which calculates and displays graphically information on the planets and their major satellites. Its aim is primarily to help amateur astronomers understand and see Mars, Jupiter, and Saturn and the phenomena associated with their satellites. ( 15 October, 2015. The website should now be usable in that the executable file of the program described can be accessed and run. Further modifications will be done, especially towards showing and running the source code.)
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.
Betelgeuse, α Orionis
α Ori is spectral class M2, with a low surface temperature of 3400K. It is well known to be a red giant star with a distinctive orange appearance through binoculars.
Gamma Velorum or γ Vel, is a very hot Wolf-Rayet (WR), star of spectral class WC08.
It has been called the “Spectral Gem of the Southern Skies”.