1999 July 23 - brief session mainly on emission line stars. Central star illuminating NGC 7023 in Cep revisited. H-aplpha strong in emission; hint of emission between absorption lines H-gamma and delta. SSCyg revisited about minimum mag and much more interesting [ie many emission lines] than at maximum about 1999 June 8. PCyg and beta Lyr also captured.
1999 May 29: repeat spectrogram of NGC7023 virtually identical to last month's (boxed) including best focus in blue/green region. Again it shows a broad H-alpha emission (perhaps implying high deferencial outflow) and H-gamma+H-delta sharply if faintly in absorption. H-beta absent or too weak to record at this resolution (4nm/pixel).
1999 April 28: chance 'discovery' of an emission line spectrum for the central star in NGC7023 in Cepheus followed an observation of T Cep (see Mira page) a few degrees away. The central NGC7023 star shows H-alpha strongly but no other emission lines. There is a hint of faint absorption lines in blue (to left) and in red (right) the bold 'A' line, faint 'a' and 'B' (nearest H-alpha) from the earth's atmosphere are recorded. From the the spectrum trace the star is probably a hot O - A type star (Burnham's CH quotes B5e) 'illuminating' the nebula itself which was not recorded.
Megastar quotes NGC 7023 = LBN 487 - a bright nebula 14'arc diam with open star cluster to west. GSC 4460:3015 is the central mag 7.4 star (recorded here)
1999 March 26/27 - GP Cep, captured during a rare session below Polaris, proved to be a Wolf-Rayet 'nitrogen' star with emission lines.
1998 Nov 16 - these are some early spectra (mainly emission line stars) captured with the Rainbow grating ~20mm from the CCD surface in the convergent beam of the 30cm f/10 LX200 SCT. The 'profiles' via the MX9 Pixwin operating software with exposure times varying from 1/20s (Vega) to 60s (Titan). Similar series used to illustrate my review of the Rainbow grating in the June'99 issue of Astronomy Now.
Spectrum of T Tau at the heart of Hinds Variable Nebula in Taurus just west (right) of the Hyades. Currently ~ mag 10 according to BAA VSS - it is unusual for a cooler star to show emission lines identified here as H-alpha and H-beta. The 'A' absorption line (oxygen in earth's atmosphere) well shown and a useful 'static' marker. T Tau's spectra F-K (F8Ve - KIIV-Ve) is also variable.
