Early spectroscopic Changes in Gamma Cassiopeia seen with a Cooke
Stanley E. Percival, Merriott Vicarage, Somerset observing with a 3.75 inch Thomas Cooke and Sons telescope reported that the bright hydrogen line C has been very bright recently in Gamma Cassiopeia.
He reported on May 2nd 1906 that he failed to see the C line, while on May 4th he saw it quite distinctly. On May 18th although the sky was clear and the spectrum steady he barely glimpsed it.
|Gamma is the middle star in the 'W' of Cassiopeia|
He notes that in Miss Clerke’s ‘Problems in Astrophysics’ page 248 that it has previously behaved in a capricious way, and if my small Cooke telescope is to be trusted it looks like it is doing so again.
Spectroscopic changes appear to have started around 1927 so this could be a much earlier report than is generally accepted. The spectroscopic variations did seem to occur some years before the light changes were detected.