P Cygni Spectroscopy Observing Campaign
P Cygni (34 Cyg) is a hypergiant Luminous Blue Variable (LBV) star, one of the most luminous stars in the Galaxy. The star is known since its eruption in 1600, flaring to 3rd magnitude at the date. Over the next hundred years the star continued to undergo outbursts, fading and brightening (the actual magnitude is near V=4.8.). The spectral profile of many lines is characterised by intense emission flanked by absorptions on their violet edges. For more infos about these very peculiar star and important object for astrophysics: http://www.aavso.org/vsots_pcyg
The international observing campaign, Photometry and Spectroscopy of P Cyg, begun in 2008, is a co-operative project of the American Association of Variable Star Observers (AAVSO), Active-Spectroscopy-in-Astronomy (ASPA) and Bundesdeutsche Arbeitsgemeinschaft Veränderliche Sterne (BAV). Photometric and spectroscopic changes in P Cygni are shown to be anti-correlated on short- and long-term scales - see AAVSO News letters (Jan. 2011): http://www.astrospectroscopy.de/P%20Cyg%20report%20AAVSO%20Newsletter.pdf
The goal of the campaign is to compile high quality spectra of P Cygni for confirm and consolidate spectral and magnitude correlation variations.P Cygni coordinates (2000.0 equinox): R.A. = 20 h 17 m 47 s Dec. = +38° 01' 59''
Change of Halpha spectral profile
for two dates (eShel spectra, telluric lines and Earth heliocentric radial velocity
Comparison of EW et V (Ernst Pollmann compilation - October update).