Abstract
In the early days we used to speak about mass loss, not of stellar winds. Of course, earliest in the game, stars were supposed to be well-behaved, but this was long before photography showed that the nova/supernova phenomena involve loss of matter from a stellar object, and spectroscopy had disclosed the existence, in the spectrum of number of stars, of what we now call a P Cygni-type profile. The first bright nova of the present century, indicated velocities of approach in excess of 1000 km/s, and an expanding nebulosity around the object was independently discovered in 1916, by W.H. Steavenson and by E.E. Barnard (cf., Struve and Zebergs 1962a). Another important element on the same question is connected to the star, in the constellation of Cygnus, that underwent a nova phenomenon in the year 1600. It corresponds to the object that we now know as P Cygni = HD 193237 = HR 7763 = 34 Cyg and is shining as a 5th magnitude object since 1715. On August 8, 1600 (cf., Underhill 1966) the object reached the 3rd magnitude, and then displayed varying brightness, being of 6th magnitude in 1620, then becoming fainter and again becoming as bright as of 6th magnitude in 1654, of 5th magnitude in 1655 and, then, of 3.5 mag, the same year, remaining that bright up to 1659. The line profiles which are characteristics of P Cyg were first detected with a visual spectrograph by W.W. Campbell, a fact that was reported in 1894, and were also noted on the Harvard objective prism spectrograms. The interpretation that is accepted for the P Cyg profiles is the one that was first put forward by C.S. Beals in 1929 (see Beals 1929, 1955), when he undertook an investigation of the Wolf-Rayet stars. Such an interpretation traced the origin of the profile to atoms being continuously ejected radially from the star at the velocity suggested by the profile's shortward absorption.
