Effects of Mass Loss on Stellar Evolution

The IAU Colloquium No. 59, "The effects of mass loss on Stellar Evolution" was held on September 15-19, 1980 at the International Centre for Theoretical Physics, Miramare, Trieste (Italy), under the auspices of the IAU Executive Co~ mittee and the Italian National Council of Research. The planning of this conference began two years ago du­ ring the IAU Symposium No. 83 "Mass loss and evolution of 0 type stars" (Qualicum Beach, Victoria, Canada) when we felt that mass loss and its effects on the evolution of stars was too broad a subject for being confined to 0 type stars only. Therefore we thought that a conference dealing with the general problem of mass loss across the whole HR diagram would have been of interest to all people working in the field. The main idea was that bringing together Astronomers and Astrophysicists of the widest range of interests and e~ pertize - all in some way related to the problem of mass loss from stars - would have spurred thorough discussions on the many aspects and implications of this topic. We hope this goal has been achieved. Furthermore, the most recent observational and theoreti­ cal developments on the problem of mass loss from early ty­ pe stars avoided this meeting to be a simple updating of the Qualicum Beach Symposium as far as this issue is concerned.

Session I — Winds From Early Type Stars: Observations.- Observations of stellar winds in early type stars (invited lecture).- The dependence of mass loss on the basic stellar parameters. (invited paper).- The velocity characteristics of WR stellar winds.- The iron curtain of the WC 9 star HD 164270..- Is a stellar wind inherent in WR-stars throughout the whole of their evolution?.- Wind characteristics of the 07 n star HD 217086 in the Cep OB 3 association.- Mass loss from central stars of planetary nebulae.- Mass loss rates of OB stars derived from infrared observations.- Profils de la raie H? par television analogique.- Radio observations and the mass flow rate of ? Cyg (A2 Ia).- Mass loss rates for twenty one Wolf-Rayet stars.- Mass outflow in AG Carinae and a comparison with P Cygni.- Mass loss from hot stars below the main sequence.- On the stellar gravity and effective temperature dependence of the ratio of terminal to escape velocities in stellar winds.- Observational evidences of stellar wind.- The radial velocity variations in IC 418.- Session II — Winds from Late Type Stars: Observations.- Mass loss from cool stars (invited lecture).- Outflow of matter in the chromosphere of ? Orionis.- Mass loss from ? Ori.- On possible mass loss from the supergiant RHO Cassiopeia.- Photospheric molecular line profiles in cool stars.- Session III — Winds from Early Type Stars: Theory.- The theory of winds in early type stars (invited lecture).- Stellar variability and individuality: observations and implications (invited paper).- Possible links between supersonic stellar winds and the origin of cosmic rays.- Line formation in the wind of Alpha Cygni.- Empirical wind models from detailed UV line fits: Tau Scorpii.- Can hot star winds be driven by radiation pressure?.- Radiative wind acceleration in early type stars..- Radio observations of O-type stars.- Narrow components in UV line profiles as evidence for a two component stellar wind for O and B stars.- Session IV — Winds from Late Type Stars: Theory.- Winds in late-type stars: Mechanisms of mass outflow. (invited lecture).- The fluctuation theory of the stellar mass loss (invited paper).- Session V — Mass Loss and Stellar Evolution: Massive Stars.- Mass loss and evolution of massive stars (invited lecture).- The fraction of O-type supergiants in our galaxy in the LMC and in the SMC: an evidence of the correlation between mass loss rate and chemical abundance.- Evolution of a 30 M? star: the interplay of nuclear burning and mass loss.- On the significance of mass loss for the evolution of massive stars.- The ultraviolet to infrared spectrum of the large mass loss LMC supergiant S22 = HD 34664.- The influence of mass loss by stellar wind on the evolution of massive helium burning stars.- Stellar evolution with SMC chemical abundances.- Massive stars burning helium: the numbers of WR stars and red supergiants in galaxies.- Thermal instability of hydrogen burning shells in very massive stars.- Effects of a stochastic initial mass function on the upper main sequence band.- Mass loss from metal-poor stars.- Masses of Magellanic Wolf-Rayet stars: mass loss and evidence for a WR subclass vs. mass relation.- How massive the Wolf-Rayet stars are?.- The hydrogen/helium ratio on the surface of Wolf-Rayet stars.- Peculiarities in the distribution of galactic Wolf-Rayet stars: constraints on evolutionary scenarios?.- Session VI — Mass Loss and Stellar Evolution: Low Mass Stars.- Evolutionary effects of mass loss in low mass stars (invited lecture).- The initial/final mass relation for stellar evolution with mass loss.- Formation of a planetary nebula by continuous mass loss.- Effects of mass loss on the formation of planetary nebulae.- Miras, mass loss, and the origin of planetary nebulae.- Theoretical evidence of mass loss from globular cluster stars.- Effect of mass gain on stellar evolution.- Session VII — Mass Loss and Stellar Evolution: Intermediate Mass Stars.- On the consequences of mass loss from intermediate mass stars (invited lecture).- A determination of the characteristics of Cepheids from B-type companions.- What “masses” for Cepheids?.- Response of low-mass main sequence stars to accretion.- Session VIII — Effects of Mass Loss on The Evolution of Binary Stars.- The influence of mass loss on the evolution of binaries (Invited lecture).- Mass loss from interacting close binary systems (invited lecture, presented by C.D. Keyes).- Ionization effects in stellar winds of massive X-ray binaries.- Non conservative massive binary evolution (how much mass leaves the binary during the evolution from OB+OB to WR+OB).- On the evolutionary time scale of the accreting component in massive close binaries: consequences for the supernova event.- Observation of mass loss in R Cr B during the visual light minimum.- Non conservative evolutionary scenario for 100 Algols.- Infrared observations and mass loss of the binary system V86l Sco.- The nature of V86l Sco (=HD 152667).- Ultraviolet and optical observations of the mass-losing contact binary SV Centauri.- Mass transfer and stellar wind effects in the eclipsing binary RT Andromedae.- Properties of optically thick winds driven by radiation pressure.- Interacting stellar winds in a binary system.- Evolutionary computations for intermediate mass close binary systems.- Is this diagram an argument for binary orbital evolution due to mass-loss?.- Nova AQL 1918: a nude old nova.- Session IX — Effects of Mass Loss on the Interstellar Medium.- Stellar mass loss and HII region morphology in Magellanic irregular galaxies (Invited paper).- Stellar mass loss and galactic chemical evolution.- Subionization and decelerated flow in the vicinity of a B shell star.- Mass loss and ?Y/?Z ratio.- Concluding Remarks.- Author Index.