SIAMOIS Sismomètre Interférentiel A Mesurer les Oscillations des

SIAMOIS Sismomètre Interférentiel A Mesurer les Oscillations des Intérieurs Stellaires Seismic Interferometer to Measure Oscillations in the Interior of Stars Benoît Mosser, Tristan Buey, Claude Catala, Michel Auvergne, Thierry Appourchaux, Annie Baglin, Caroline Barban, Marc-Antoine Dupret, Marie. Jo Goupil, Jean-Pierre Maillard, Eric Michel, Reza Samadi, Francois-Xavier Schmider, Frédéric Thévenin, Gérard Vauclair, Denis Fappani et al. Observatoire de Paris/LESIA, IAS, UNSA/LUAN, OMP/LATT, IAP, OCA June 15, 2006 ARENA workshop 1

Asteroseismology What asteroseismology teaches us ? …. Example of the Sun The Sun without asteroseismic constraints ! June 15, 2006 ARENA workshop 2

Asteroseismology What asteroseismology teaches us ? …. Example of the Sun The Sun without asteroseismic constraints ! June 15, 2006 ARENA workshop 3

Asteroseismology after COROT 1 st step: photometry, space-based observations 2 nd step : spectrometry, ground-based obs. Complementary observations • Bright stars • Low mass stars • Doppler signal reduced granulation noise, modes l=3 Scientific specifications: continuous observations, long duration June 15, 2006 ARENA workshop 4

SIAMOIS at Dome C Demanding site ? Project ~ spatial organization Quasi automatic, simple setup Reduced mass, power, telemetry Seeing ? Fibre = 5" on the sky No big telescope available Key science with a 40 -cm telescope at Dome C ? Only circumpolar targets ? Enough interesting bright targets for more than 6 winterings Duty cycle ~ 90% ! Scientific specification #1 : duty cycle > 85% Polar night = 3 months Scientific specification #2 : 100 -day long run on the same target June 15, 2006 ARENA workshop 5

Scientific program Observable targets with SIAMOIS and a 40 -cm telescope dedicated to the project COROT • 40 -cm telescope: - 7 targets, type: F, G, K class: IV & V - many red giants; d Scuti (v sin i < 20 km/s) Scientific programme for more than 6 winterings June 15, 2006 ARENA workshop 6

Overall description • Divided in four sub-systems : – A dedicated Telescope with its Bonnette (telescope guiding and fiber coupling). – An Interferometer and a Camera. – A structure for thermal and mechanical control. – A command/control software system. • Divided in five laboratories : – GIGT from OMP (Observatoire Midi-Pyrennée). – LUAN from OCA (Observatoire Côte d’Azur). – IAS (Institut d’Astrophysique Spatiale). – LESIA from OPM (Observatoire Paris-Meudon). – CSIC from Institutode Astrofisica de Andalusia (in discussion). • One associated private contractor : – SESO (Société Européenne de Systèmes Optiques). June 15, 2006 ARENA workshop 7

Instrument Dedicated Telescope Bonnette Optical fibers : signal and calibration Vacuum pump Thermo-mechanical structure. Optical bench. Interferometer Camera Calibration Command/control system: Acquisition, image processing … June 15, 2006 ARENA workshop 8

Instrument • 40 -cm telescope • Interferometer • Post-dispersion June 15, 2006 low cost, easy ‘antarctization’, dedicated to the projet monolithic instrument no moving part, reduced size fiber fed efficiency, photon noise limited performances ARENA workshop 9

The constraints. • Small budget and short planning… • High reability of the instrument : – Observation requirements : 90% of duty cycle. – Very difficult to fix anything at Dome C in Antarctica. • Very easy to use : – Not easy set-up at Dome C in Antarctica (once again : -) ). – Wintering will insure a minimal maintenance. • Rather hard environmental conditions : – Shocks and temperature (level and gradient) during transportation and storage. – Temperature, humidity and pressure during operation. June 15, 2006 ARENA workshop 10

Planning • 2004 - design - Achievement of the feasibility phase. • 2006 - thermo-mechanical analysis - Qualification tests. • 2007 - PDR - FDR • 2008 - integration • 2009 - tests - summer campaign: Dome C • 2010 - first winterover at Dome C Laboratories: LESIA (Obs. Paris), IAS (Orsay), LUAN (Nice), LATT (Toulouse) + SESO June 15, 2006 ARENA workshop SIAMOIS Interferometer JP Amans, GEPI, Obs Paris Coast : Including ANR : 860 k€ 460 k€ For phase A in 2006 (ACI + CSA + PNPS) : 116 k€ 11

Development Philosophy • Step I : Establish all the requirements of the sub-systems and the interfaces between them. • Step II : Develop the test benches and equipments, write the invitation to tender for the industrial contractors. • Step III : Develop the sub-systems (industries and laboratories) or buy them directly when possible (budget and specifications). • Step IV : Individual acceptance of each sub-systems. • Step V : Environmental qualification. • Step VI : Integration of the sub-systems together up to the instrument level. • Step VII : End-to-end test in laboratory and on the sky, final setup. • Step VIII : After transportation to Dome-C, simple integrity test. • Some revue are foreseen during the project development. • Like “space instrument” development : quality, management of configuration, documentation, revues… with limitations! June 15, 2006 ARENA workshop 12

Conclusion • Dome C: a unique site for asterosismology 3 -month continuous observation with duty cycle ~ 90% • A specific scientific program after • High performances with a 40 -cm collector – – – Pioneering project at Dome C FT seismometry: suitable concept for installation and setup at Dome C Multiplex advantage of FT spectrometry Small instrument : < 300 kg, < 2 m 3, < 1 k. W, … Rather fast development with a demonstrate feasibility. ‘‘Big science’’ at Dome C with a budget < 1 M€ June 15, 2006 ARENA workshop 13