I am happy the data reached you okay. We will look forward to hearing
Dear Elizabeth, dear Arne!
Thanks again for your kindly support regarding brightness data of P Cyg.
Meanwhile I tried to correlate the Halpha equivalent width with your V-data (see attached plot).
The available EW data have been collected from different professional publications and on the other hand from my colleagues of the VdS spectroscopy group and from colleagues of the french ARAS group. The lower plot shows the "correlation" between the visual estimated brightness and the EW.
I am sure this result don´t need any further interpretation. V-data on the basis of visual estimations are absolutely unsuitable to monitor the current S-Dor phase together with Halpha EW in kind of correlations.
This statement is not surprising if we remember the publications of N. Markova in 2001 (A&A 376, 898-906 and A&A 366, 935-944).
One of the main aspect in her investigations is the use of photometrical V-measurements. The results in her investigations are showing this impressive.
But meanwhile the data base became much bigger and longer then the time section she used, and the question is how we may get photometric V-data for our further amateur investigations.
Well, some colleagues of the variable star observer organisation BAV in Berlin told me you would participate at the Variable Star Conference in September in Potsdam. I intend too to be there. We could use this wonderful opportunity to discuss about the question of the future important necessity to collect rather photometric data in your data base.
What´s your opinion?