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Carbon star spectral features


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About this observation
Kevin Gurney
Time of observation
26/10/2018 - 23:58
WZ Cas, W Ori
Observing location
West Sheffield
Altair Astro 10in RC truss tube
LHires 600l/mm
Atik 460EX
MESU200 mount
Prism, Demetra, Isis
6 subs at 300s each

I decided it would be refreshing to look at something  other than H alpha in Be stars for a change...

Richard Walker has a good section on Carbon stars in his Spectroscopic Atlas which inspired me to look at some of the highlights therein.

WZ Cas has strong Lithium absorbtion at 6708A (panel b), and an even stronger sodium absorbtion around 5890. This is in fact a doublet which is just visible (I think!) in my medium resolution spectrum (panel a)

In contrast, W Ori has no strong Lithium absorbtion (panel d), but has a complex of lines at the blue end know as Merrill Sanford bands, apparently due to Silicon dicarbide (SiC2) - see panel c

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