The ISO-SWS spectrum of P Cygni.
Waters, L. B. F. M.; Hillier, D. J.; Kudritzki, R. P.; de Graauw, T.; Morris, P. W.; Lamers, H. J. G. L. M.; Najarro, F.; Beintema, D.; Valentijn, E. A.; Voors, R. H. M.; van Gent, J. I.
Abstract
The free-free IR excess and the IR emission lines of H and He I of the Luminous Blue Variable P Cygni are observed with the ISO-SWS instrument. The observed profiles and the free-free emission are compared with predictions from a non-LTE model atmosphere with a stellar wind. The observations agree very well with a model that has the following properties: T_eff_=18100K, R_*_=76Rsun_, He/H=0.30 by number, ˙(M)=3.0x10^-5^Msun_/yr and vinfinity_=185km/s. We observed forbidden emission lines of [Fe II], [Fe III], [Ni II], [Ne II], [Ne III] and [Si II]. From the study of the [Ne II] and [Ne III] lines we find that the Ne abundance is about three times higher than normal. This may be due to clumping in the CS envelope at r=~10^3^R_*_.