head 1.1; access; symbols; locks http:1.1; strict; comment @# @; expand @b@; 1.1 date 2004.11.30.14.51.07; author PaoloPadovani; state Exp; branches; next ; desc @none @ 1.1 log @none @ text @ Which star will go Supernova next ? Proposal for an AVO Science Reference Mission by F. Kerber (ST-ECF) Introduction ------------ The late phases of the evolution of massive (>8 Msun) and the physical changes of the star leading up to a supernova explosion are not well understood. The main reason, of course, is that no Galactic supernova has been observed for 400 years. Massive stars, their wind blown circumstellar nebulae and their supernova explosions are main contributors the chemical enrichment of the interstellar medium (ISM) and exert an important influence on its dynamics. This makes them main drivers of the chemical evolution of galaxies and the formation of stars. About 400 highly evolved massive stars are known in our Galaxy. Most or these stars are bright sources from the X-ray (hot and fast winds, supernova remnants (SNR)), through the UV (winds and star and circumstellar matter), the visual (star and circumstellar nebulae), IR (star and dusty circumstellar matter) into the radio (circumstellar nebulae and SNR). Because they are bright a wealth of data spanning a large wavelength range is available for them. In a significant number of cases the data cover very long periods of time which is most relevant for this variable and quickly evolving objects. By combining the existing multi-wavelength data AVO promises to provide new insight and can demonstrate its potential as a true discovery tool. This project will require an intensive exchange between obervation and stellar modeling based on physical theory. In addition it will open the interesting time domain. The AVO will become decidedly more powerful with the inclusion of theoretical models and the time domain. One important result will be to establish a list of possible candidates for the next SN, which could then be monitored more closely. Of course, no one can predict when the next Galactic supernova occurs but statistically it is clearly overdue. This makes such a project a timely effort which will put us in a position to take maximum advantage of the next Galactic supernova when it actually takes place. Moreover an improved understanding of the massive stars and their influence on the evolution of galaxies will be fundamentally important for the correct interpretation of observations of the distant and early universe. Main objectives --------------- - combine existing heterogeneous archives to build a multi-wavelength, multi-epoch data cube of the star and its environment and SNR - extract a status quo of knowledge on evolved massive stars - search for common features and derive evolutionary sequence - ranking of SN candidates and list of likely next SN - study interaction between circumstellar nebula and the ISM Scientific Relevance -------------------- - supernova explosions are of fundamental importance to nucleosynthesis - SNe drive chemical evolution of galaxies - determine dynamics of interstellar medium, trigger star formation - possible relation to GRBs Practicability -------------- - huge multi-wavelength, multi-epoch archives exist (bright objects) - active community (observational & theory) exists in Europe - solid basis of stellar evolution, nuclear processes exists - local galaxies within reach of our instrumentation - modern technology (AO, VLTI) give access to circumstellar environment, mass loss history - different wavelength domain probe different aspects of the objects: stars, stellar wind, circumstellar nebulae providing the opportunity to develop insight into the full range of phenomena associated with massive stars and supernovae - Galactic SN explosion is overdue VO Aspects ---------- - Data: - large body of relevant multi-wavelength and multi-epoch data exists - better use of existing data - combination of data with different resolution etc, emphasises need for meta data - add time domain to VO - include theory (stellar modeling) in VO - Tools: - cross matching tool to combine data from different sources for each individual source - tool for comparison of obseravtions with models (spectral cross correlator) - tool for extraction of data in time domain - visualization tool for data from different wavelength regions obtained at different resolution etc VO Need ------- Study of individual stars have been done in the past. A comprehensive view of the known most massive stars requires full use of large data volumes distributed over diverse archives. VO tools for analysis and combination of such data will greatly facilitate their interpretation. Inclusion of the time domain and quantitative comparison with theory/models in the VO context will truly enable new and better science. Relevance to astronomical community ----------------------------------- - very fundamental questions addressed - real service to community (after SN there will be rush to find pre-explosion data and explain things) - prepare community for next SN, which will be one of the most important events for astronomy to exploit - enable us to ask better questions, write better proposals - prepare observatories for SN event, have suitable telescope/instrument Education & Public Outreach --------------------------- - large Amateur community involved by default (photometry, AAVSO) - superlatives: most massive, hottest ... - "Top Ten" list of SN candidates should appeal to public - body of solid and accessible physics: stellar evolution, children of the universe - nice images of circumstellar matter/nebulae - possible effect of nearby SN on life on earth, previous mass extinctions - link to GRBs @