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Disks, Meteorites, Planetesimals Workshop (2010) DUST FROM EVOLVED STARS TO PROTOSTARS. A. K. Speck, University of Missouri ([email protected]) Introduction: Dust is a vital ingredient in understanding many astrophysical processes [e.g. 1, 2, 3]. It is an essential part of star formation processes; it is the key to understanding mass loss from aging stars [e.g. 4]; and it contributes to several aspects of interstellar processes such as gas heating and the formation of molecules [e.g. 5]. Furthermore, dust has been observed at higher redshifts than expected, and understanding this phenomenon is vital to our understanding of the cosmos at large and its evolution [e.g. 6, 7].Such a crucial and ubiquitous constituent of our Universe needs to be well understood in its own right, if we are to understand its contributions to many aspects of astrophysics. Evolved Stars: Intermediate-mass stars (0.8-8.0 solar masses) are major contributors of new elements to interstellar space [8]. These stars eventually evolve into asymptotic giant branch (AGB) stars. During the AGB phase, these stars suffer intensive mass loss leading to the formation of circumstellar shells of dust and neutral gas, including the new elements formed during the star’s life [9]. Using a combination of observing techniques (e.g. infrared (IR) spectroscopy, visible, IR and sub-mm imaging) and laboratory IR studies, combined with theoretical considerations (e.g. kinetics and thermodynamics of the dustforming region; nucleosynthesis models and changing stellar chemistries) and meteoritic evidence. Combining astrophysics and meteoritics: Understanding the interplay between observational and theoretical astrophysics and meteoritic studies of presolar grains is crucial to furthering studies of dust in space. This is especially true for dust around evolved intermediate mass stars, where the majority of meteoritic presolar grains originate. New laboratory data combined with reanalysis of observational data for AGB stars will be presented. Combined, these data present a challenge to the “common wisdom” on what we think we know about dust species in space. References: [1] Videen, G., Kocifaj,, M., eds., 2002, Optics of Cosmic Dust (NATO SCIENCE SERIES: II: Mathematics, Physics and Chemistry, vol. 79), Springer, pp 320. [2] Draine, B. T., 2003, Astrophysical Journal, 598, 1017. [3] Krishna Swamy, K. S., 2005, Dust in the Universe: Similarities and Differences, World Scientific Publishing Co., p. 264. [4] Woitke, P., 2006, Astronomy & Astrophysics, 460, L9. [5] Krugel, E., 2008, An Introduction to the Physics of Interstellar Dust, Taylor & Francis, p. 387. [6] Sloan et al., 2009, Science, 323, 353. [7] Bussmann et al., 2009, Astrophysical Journal, 705, 184. [8] Kwok, S. 2004, Nature, 430, 985. [9] Iben, I. Jr., Renzini, A. 1983, Annual Reviews of Astronomy & Astrophysics, 21, 271. 6018.pdf