5th DMS/PS meeting October 8 Welcome!

1. 5th DMS/PS meeting October 8Welcome!

2. Meeting agenda • Halbwachs J-L. Astro. binaries with a variable component • Pourbaix D. Colour-induced binaries • Pourbaix/Jancart Spectro binaries code • Söderhjelm S. Simulations using a single-star galaxy • Other possible talks or comments on posters: • Dischler J. (Eclipsing binaries), • Arenou F. (performances with GDAAS ASM data handling), • Nurmi P., (on-going work: simulations, imaging) • … • Discussion  • Simulation tasks: how to implement them in the "Gaia Object Generator", how to introduce multiple, variables for DMS? • DMS work packages: status of the various algorithms, what is missing, what priorities? How to optimize them? How to combine their results? • Test campaign: how to implement an end-to-end test (from the various, and varying, on-board strategy features to the various final parameters), under which schedule? DMS - Paris meeting 5

3. Symposium presentations/posters • Presentations/posters at the symposium • Census of binaries - the big picture, S. Söderhjelm • Stellar wobble in triple systems mimicking a planet, J. Schneider • Automatic parametrisation of Gaia spectroscopic binary stars, T. A. Kaempf et al. • Observing faint binaries with GAIA, P. Nurmi • Galaxy simulations of binary stars, P. Nurmi & H. Boffin • Identification of Spectroscopic Binaries by Medium Band Photometry, Willemsen et al. • Duplicity and masses, D. Pourbaix • Data reduction for double and multiple stars, F. Arenou & S. Söderhjelm • Predicted properties of eclipsing binaries observable with Gaia, J. Dischler & S. Söderhjelm • Astrometric binaries with a variable component, J-L. Halbwachs & D. Pourbaix • Orbit determination for Gaia spectroscopic binaries, S. Jancart & D. Pourbaix • Hipparcos astrometric binaries in SB9, S. Jancart et al. • Fundamental stellar parameters from double-lined eclipsing binaries, P.M. Marrese et al. • The physical parameters of close E.B. derived from Gaia photometry, P.G. Niarchos et al. • New numerical minimization algorithms for analysis of eclipsing binary stars, Prsa & Zwitter DMS - Paris meeting 5

4. Since Brussels meeting • Pasi Nurmi one week in Meudon • Discussion with M. Haywood about galaxy model with BSE code • Simulations • Inclusion of DMS in single star simulated Galaxy, by S. Söderhjelm, DMS-SS-05 • Orbits • A better spectroscopic orbit (short periods) algorithm (D. Pourbaix) • Training student on “photocentric” binaries (C.I.D.) • 106 with photocenter displacement between 2 bands > 1s • 105 detections with 1/1000 false detections? • Identification and parametrisation of binaries in MBP • Willemsen, Kaempf, Bailer-Jones, ICAP-PW-003 • CPU estimation : • Staffan Söderhjelm, Pasi Nurmi, Andrej Prsa, Claire Dollet, Dimitri Pourbaix DMS - Paris meeting 5

5. Last DMS meeting goals • A short term plan • Realistic simulation software: • Beginning of test campaign: September 2004 • Reports on DMS algorithms capabilities and improved science case: end 2004 • Reappraisal of the algorithms definition: early 2005 DMS - Paris meeting 5

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8. Frédéric Arenou Carine Babusiaux Coryn Bailer-Jones Henri Boffin Johann Dischler Claus Fabricius Paul Groot Jean-Louis Halbwachs Sylvie Jancart Patricia Lampens Oleg Malkov Francois Mignard Pasi Nurmi Dimitri Pourbaix Noël Robichon Dimitris Sinachopoulos Staffan Söderhjelm Hans-Heinrich Bernstein Melvin Davies Claire Dollet Misha Haywood Erik Hoeg Carme Jordi Roberto Morbidelli Panagiotis Niarchos Edouard Oblak Julienne Palasi Renato Pannunzio Ignasi Ribas Alessandro Spagna Toma Tomov Christopher Tout Vladas Vansevicius Hans Zinnecker Core + Associate members DMS - Paris meeting 5

9. Organisation • Membership: • 17 core+ 17 associates • In effect: much less FTE? 3-4? • New (after Gaia 2004): A. Prsa, P. Willemsen, • Funding: • Opportunity in Meudon to work on an end-to-end test (on-board design => dense regions) one year (funding to be finalised) • Greece • Encouragement for others… DMS - Paris meeting 5

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12. Actions • C.I.D./photocentric binaries • F.Arenou+D.Pourbaix to give the statistical tests which have been used for the C.I.D • Staffan (+ideas from Lennart) to compute the number of objects and place in Dm/P • V.I.M (variable component) • JLH: using BBP can give color information on components • JLH: try to get actual numbers + improvement of algorithm • JLH: technical note (input from Dimitri) • Algorithms • Dimitri: is interested by astro+RV in multiples (after tackling doubles) • Simulations • Annie Robin/Staffan/Pasi: Exchange of data and comparison tests done before the next meeting • Next meeting: 14 April, Geneva (to confirm) • After the PS meeting DMS - Paris meeting 5