A spectrum of Vega recorded 4/12/2013 from Chipping Norton Airfield.
Look – no telescope! Cannon 400D + Leica R 90mm f2.8 + StarAnalyser 100 grating
A single shot 0.5 secs at about f4 ( grating filter stop ) and ISO 800
The graphical image is from processing with IRIS + VSPEC software.
Dark blue line is the recorded data
Red line is from a library of “standard” spectra – in this case an A0V class star.
Light blue peaks indicate element transitions – hydrogen only selected and show from the left hydrogen gamma (434.0 nm) , beta (486.1 nm) and alpha (656.2 nm).
I guess a modified camera-filter would improve things at the red end.
Yes Mel just Vega selected – you don’t need many pixels for this game!
With well separated bright stars and short exposures it works ok – anything closer can cause an overlap of the dispersions which is then impossible to untangle.
I’ll try a busy star field for a demo next time.
This is fascinating. I’d like a go at this myself. My dad, who was one of the founders of the OU (the Faculty of Technology was his idea), got hold of an old spectrograph (a little black tube) so I’ve been fascinated by spectra since I was a little girl. I don’t know very much about them though!