P Cygni 8th July 2005

P Cygni is a Blue Supergiant and is one of the most luminous stars in the Galaxy. It is famous for the characteristic spectrum line profile which bears its name. (an emission line paired closely with a blue shifted absorption line)

This spectrum was recorded using the 100 l/mm grating. The slit was narrowed to reduce the sky glow from the twilight sky. The star was bright enough not to require long exposure mode on the camera.

SC3 "PIPCAM" +VC200L @ f6.4

Emission lines due to Hydrogen and Helium can be identified. The characteristic P-Cyg blue shifted absorption bands are not resolved however at this low dispersion. (A dispersion at least 5x greater would be needed)

Beta Lyrae (Sheliak) 8th July 2005

Beta Lyrae is the prototype for a class of variable star which are close eclipsing binaries. The two stars orbit each other every 12.9 days. They are so close that the larger star is distorted into an elipse and there is evidence that matter is being exchanged between the two stars.

This spectrum was recorded using the 100 l/mm grating. The slit was narrowed to reduce the sky glow from the twilight sky. The star was bright enough not to require long exposure mode on the camera.

SC3 "PIPCAM" +VC200L @ f6.4

Note the out of focus "fish tail" effect at the violet and infra red ends of the spectrum due to the eyepiece not being well corrected chromatically beyond the visual range.

Emission lines for Hydrogen alpha and possibly Helium can be seen.