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Published byJosephine Madeleine Nicholson Modified over 8 years ago
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Some preliminary conclusions i) This mini-workshop: intended as an inter-CRP Eurogenesis meeting ii) Putting it immediately after Acona helped in having colleagues from USA, while paying only once the intercontinental flights. iii) On the other side it made difficult for several Europeans to come. Hence we had only few representatives from other CRPs (Decressin: First Stars; Chieffi: MASCHE; Longland: ExNuc). Thanks to them for coming and contributing! iv) As a consequence, some (excessive?) emphasis turned out to be given to the specific activities of IP5 in CoDustMas (nuclear astrophysics). v) Thanks to the specially invited external contributors (Andy, Inma, Carlos, Maria, Franz, Ernst) for making the program more complete. vi) Levy Strauss used to say that “Scientists are not only those who give the answers, but also those who ask the questions”. vi) Profiting of this, I’ll only pose some questions, emerged in this meeting (in some cases also in Ascona), counting on my colleages at this table and in the room to provide answers….
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IMSs i)C-stars are of low mass (Cristallo). Previous hints that they reach up to 4-5 M (Barnbaum & Zuckerman) not confirmed recently. Also O-rich stars are not seen at high mass (Guanbdalini & Busso in preparation). Maybe selection effects, simply….. BUT: AGB nucleosynthesis, once attributed to IMS, now recongnized to be from lower masses (Davis, Kaeppeler, Zinner, Maiorca, Palmerini,….). NOT ONE SINGLE PRESOLAR GRAIN OBSERVED FROM IMSs. Where have all the IMSs gone????? “Possible” need for IMS dust contributions in early epochs (Dwek). Do they live shortly, e.g. only through RGB or early-AGB phases, producing dust very early, and not going to the TP-AGB phases?
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Better nuclear physics inputs? i) Many problems in presolar dust abundances, previously attributed entirely to mixing, may be related also to insufficient knowledge of reaction rates (Imbriani, Palmerini). ii) Better nuclear inputs necessary also for very heavy elements, also for dust grains (Kaeppeler, Davis). How much of this can be improved by better undergound facilities or measurement techniques (Trezzi, Gialanella, Milazzo)? How much of it can instead by due to poor theoretical approaches to general problems, like electron screening (semi-classical Debye- Hueckel treatment, but it’s from the 30’s! Is it not the time to have a reall quantistic approcah to a Fermi electron gas? Where can we find nuclear physics theorists whishing to undertake this big task? How much a better modeling of electron screening (i.e. density: Busso et al,NIC XII,PoS) can affect weak interactions?
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Basic Stellar Evolution Issues Perculiar isotopic compositions, not explained by normal, single star evolution & nucleosynthesis, early observed in SiC grains (e.g. A+B: Zinner). Some of them unexplained even in explosive nucleosynthesis scenarios (novae, WD merging: Longland). Now observed also in some stars looking, for the rest, like AGB Stars (e.g. CJ, SC….. Abia). Isn’t it time to afford from scratch the evolution of close binary systems?
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Young clusters reveal overproduction of s elements We should do any effort to have more data, stimulating the observers to look not only at GCc, but also at OCs. In any case, to interpret them we need GCE models, including dust. How good are they? Do all of them obtain the same results once given the same inputs? How large is the uncertainty in stellar lifetimes? How much are they dependent on still poorly known reaction rates?
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