wpo - some winter stars
1999 Oct 12/13: A long session 'till 4am recording the spectrum
of M42 and some winter stars plus summer stars Altair and Arcturus.
The spectra have been processed to produce a bland background continuum
and so highlight the line structure. As a result most of the stars below
have similar spectra - the dual images of Capella show the consistent results
via separate exposures as does the additional spectrum of Altair taken
two days later. Now even my doubting curiosity is satisfied with Altair's
blurred lines<g>.
Altair spins on its axis every 6.5hours
[~x100 faster than the sun!] and blurs its spectral lines through Doppler
broadening as light from opposing limbs approach [blueshift] and recede
[redshift]. The few faint but sharp lines may originate in either the earth's
atmosphere or interstellar space especially so in a very remote star like
Rigel which has a larger volume of space to sample in the line-of-sight.
return to main spectrometer page..
