P Cygni up-to-date

Dear colleagues!

First of all I would like to thank so much for all your spectra and photoelectric measurements. The current state of our campaign enables with the Hα equivalent width (Fig. 1) and Vmag (Fig. 2) to try a period analysis of the calculated intrinsic Hα line flux (Fig.3), the primary aim of this campaign.

The intrinsic Hα line flux have been calculated by division of the Hα equivalent width by the contemporaneous photometric Vmag data. These Hα line flux data enable the period analysis in Fig. 4. This so-called Scargle-diagram shows a clear dominant period of 319 days. Fig. 5 shows the phase diagram of the found period in Fig. 4

With this period we are able to improve the 310 d period of the analysis 04/2016. It will be of high interest, how this period will be stable with further data within the next years.

You should be informed that Noel Richardson (Département de physique Université de Montréal) had been interest on our data we have gotten until 2016. He intended to find out with Vmag data of the nano-satellites from BRITE campaign more or less similar periodicities. But unfortunately he didn´t give any feedback until now.

It would be really great if you could further contribute to this campaign with your spectra and photometric Vmag data.

Ernst Pollmann,16.7.2019