Sunday, 15 January 2012
The Spectrum of Gamma Velorum
Gamma Velorum - the brightest Wolf-Rayet star in the sky is sited at RA 08h09m Dec -47:20, and shines brilliantly in constellation Vela, close to the second brightest type O star Zeta Puppis. This (1998 3M1000) photo is to show what the Baader Spectroscope records. The visual view is much nicer! The star is multiple, A is the WR type, but fainter B has recorded too - & their spectra overlap.The stars were drifted in RA to widen the prime spectrum - tricky with film. The brilliant emission bands are arrowed, wavelengths in Angstroms. The faint orange line 5876A, easy visually, has barely recorded - film's response was far from linear.The UV enhancement at rhs is partly from the WR star A and secondary star B's overlapping spectrum. The bright blue and lemon-yellow lines (all carbon) have recorded well. Problem: the Airy disc of the star broadens the lines - a slit-type spectroscope would solve this, but brings more problems of design and control. Ideas welcome!