Solar System Working Group 6th Meeting ----- F. Mignard 1
Attendants - Alberto CELLINO - Aldo DELL'ORO -Marco DELBO - Enrico GERLACH - Daniel HESTROFFER - Sergei KLIONER - Claes-Ingvar LAGERKVIST -ValeryLAINEY - Ralph LANGHANS -François MIGNARD - Serge MOURET - Karri MUINONEN - Michel RAPAPORT -Heike RAUER - Michael SOFFEL -Paolo TANGA - Jenny VIRTANEN - Stefan WOLFF -ValeryMALYUTO 2
Objectives of the meeting Status of the GAIA mission Status of the actions agreed on Review of the on going acitvities and report of task leaders Future of the working group Preparation of a joint paper Set guidelines for the next six months 3
AGENDA 25/11 09h30 Meeting introduction and Gaia update F. Mignard 10h00 WG activities, membership, actions F. Mignard 10h30 Current status of the simulation. New needs? F. Mignard Update of the simulation : solar system P. Tanga 11h00 Coffee 11h30 Astrometric precision in the AF fields 12h00 How to cross-match new planets : first approach D. Hestroffer, F. Arenou, C. Babusiau F. Mignard 12h45 lunch break 14h30 Toward a catalog of relativistic effects for asteroids S. Klioner 15h00 Detection of moving objects : latest info S. Wolff 15h15 Measuring asteroids position and motion with Gaia K. Muionen & J. Virtanen 15h45 Coffee 16h15 The semi-robotic 50-60 cm telescope of Lohrman Obs. M. Soffel 16h30 Asteroid orbit improvement D. Hestroffer, J. Berthier 17h00 Masses of asteroids : formal precision M. Rappaport 17h30 On-going work on the mass determination F. Mignard, D. Hestroffer, S.Mouret 4
AGENDA 26/11 09h00 Disk integrated photometry : update A. Cellino 09h30 Update of the size measurements A. Dell'Oro 10h00 Size and shapes of asteroids: Gaia vs. GB. M. Delbo 10h30 coffee 11h00 Natural satellite dynamics, structure and V. Lainey 11h30 Cometary science with Gaia H. Rauer 12h00 Automatic CCD processing for asteroids R. Langhans 12h15 Discussions, actions, next meeting F. Mignard ~ 13h00 End of the meeting 5
Status of GAIA 6
GAIA ESA Rudi Schmidt has been appointed as project manager on 1 st July Oscar Pace (study manager) will retire by the end of 2004 Mid-term presentation of the phase B1 of industrial design from Alenia and Astrium (14-15 September) no major revision of the main concepts reassessment of the thermo-mechanical stability Concerns with the mass budget, the availability of micro-newton thruster (FEEP of cold-gas), CCD procurement times. Reassessement of the mission costs The ITT for industry is intended to be released by 15 August 2005. Phase B2 should start, with one prime contractor, in January 2006 with a target launch date of the second half of 2011. From my slide of the last meeting A launch date of 2010 implies start of B2 in April 2005 7
From the GST A common photometric system should be agreed in November Bright stars will be handled with gates Still big uncertainy on CCD radiation damage, CTE and impact on centroiding. A steering committee has been set up for GDAAS Telemetry simulator (U. Lammers, ESTEC) Simulation of the data flow from Astro, RVS, MBP Galaxy model with 10 9 objects Scanning law Day-to-day optimised GS visibility ( 11.02 +- 1.84 h/day) Compression factor of 3, dead time of 2.5% > Astro = 2 x 1.2 Mb/s 48 TB > RVS = 1.9 38 > MBP = 1.4 28 > Total = 5.7 Mb/s On board mass storage of 200-400 Gb needed 8
Galactic Model 9
Data Rate From U. Lammers, ESTEC 10
Industry Schedule 2005 Jul End of competitive definition phase 2005 Jun Begin of CCD procurement 2005 Aug I T T to industry 2005 Oct Response by industry 2005 Dec Prime contractor selected by ESA 2006 Jan Start of 5-year construction phase mid 2011 LAUNCH 11
Data processing Data processing is a community task ESA pays for: satellite, payload, launch, ground-segment ESA will not pay for the data processing (DP) Funding from national agencies DP study (GDAAS) has been running since 2001 objective: assess feasibility of DP approach system, hardware, database, integration algorithms definition and testing Replaced by data processing consortium from 2006 To develop, implement and manage DP system until ca. 2019 12
Community schedule 2004 Dec ESA s issues a Letter of Intent (LoI) 2005 Feb Response on call for LoI 2006 Jan ESA s (AO) for the data reduction 2006 Apr response by a data reduction consortium (or consortia) early 2011 readiness review of data reduction mid 2011 launch early 2017 nominal end of science mission 2019/2020 completion of data reduction, final results 13
GAIA Schedule 2000 2004 2008 2012 2016 2020 Acceptance Technology Development Design, Build, Test Launch Observations Analysis Catalogue 14
Design 15
Relative position of the FOV's Current design under study Sequence Spin axis P = 6h t = 0 Observation + 28 mn + 78 mn AF1 Spectro AF2 49.7 21.2 Astro 1 (PFOV) + 254 mn etc AF1 Spectro/MBP Astro 2 (FFOV) Scan direction 16
Focal Plane ASM1-2 AF1-11 BBP1-4 Astro Field Cell size : 49 x 60 mm 2 CCD size : 45 x 59 mm 2 600 mm 0.75 4.5 k x 2 k Pixel size 10 x 30 µm 2 = 44 x 133 mas 2 TDI : 0.735 ms Airy (along) 103 mas Integration time : 3.3 s 45 mm ~ 800 mm 0.95 59 mm 17
MBP Fields (new design) MBP 2.1 = 125s = 88 mm MBP 2.1 = 125s = 88 mm SM/NEO R V S 1.6 65 mm 1.6 65 mm R V S CCDs Scan MBP : 800 x 1960 pxs Pixel size 10 x 15 µm 2 0.9 x 1.35 arcsec 2 Full read-out or windowing mode Optical axis Integration time MBPSM ~ 6.7s MBP ~ 12.5 s RVS FOV 18
The Solar System Working Group 19
Science Goals for the solar system Systematic survey down to 20 mag ~ 5x10 5 objects Main belt NEOs Orbits: virtually all object observed - x30 better than now Masses from close encounters ~ 100 masses expected Diameter for over 1000 asteroids : shape, density Photometric data in several bands : albedo, taxonomic classification Space distribution vs. physical properties Perihelion precession for 300 planets 20
Objectives of the task Assess observability of : minor planets, NEOs, satellite, comets, KBO Set the constraints on the CCDs for the best detection of moving sources Provide operational algorithms for this detection Determine the algorithms for the orbit reconstruction (known or new objects) Provide operation alogorithms for this determination Assess the requirements on photometry for the best science return Assess the needs of and provide solar system ephemeris Provide recommendations for the quick alert mode Investigate the organisation of follow-up observations 21
Core members M. Carpino :: status A. Cellino A. Dell'Oro M. Delbo E. Dotto :: status D. Hestroffer E. Hoeg S. Klioner F. Mignard K. Muinonen M. Rapaport P. Tanga W. Thuillot J. Virtanen :: core S. Wolff E. Zappala Membership Associates C. Bailer-Jones J. Berthier F. Colas A. Doressoundiram W. Evans C. Fabricius P. Hjorth U. Jorgensen : status C.I. Lagerkvist M. Kaasalainen R. Michelsen : status A. Morbidelli J.M. Petit V. Lainey S. Mouret H. Rauer 22
Task break-down Tasks identified Leader - Asteroid size and shape A. Dell'Oro - Simulation and detection F. Mignard - Orbit determination K. Muinonen - Surface properties P. Tanga - Photometry A. Cellino - Taxonomy E. Dotto - Data base E. Zappala - Mass determination D. Hestroffer - Ground based follow-up W. Thuillot - Trojans, TNOs J.M. Petit 23
Review of pending actions 24
Actions (May 04) Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks :: this worked perfectly Accuracy of the centroiding to AF CCDs for moving objects (DH) schedule : 07/04 :: not fully completed Testing of moving objects in GDAAS (SW, FM) schedule ( a first version): 10/04 :: action in progress Updated simulation + data file available to all (FM, PT) Schedule : 06/04 :: completed Large blind testing with triaxial ellipsoids (AC,...) Schedule : 06/04 : report in this meeting Investigate the introduction of complex shape () Schedule : 25
Actions (May 04) Comet observation with Gaia ( xxx) schedule : 11/04 :: first discussion at this meeting Improved error model for the orbit determination (FM) schedule : 11/04 Check of the error model in the size determination (AO, MD) (window, RON, magnitude vs size) Schedule : 06/04 Orbits with Gaiacentric observations (KM, JV) (Gaia and solar system ephemeris from GAIA) Schedule : 11/04 26
Work on mass determination Start of PhD work of Serge Mouret at IMCCE and OCA Position funded for the next three years Steps of the work : - review of ground based mass determination - Gaia observing mode and astrometric accuracy - Definition of efficient close encounters (ECE) - Extended search of ECEs over 2012-2017 with ~ 200,000 MBO - (*) Simulation of orbits with ~ 100-200 perturbing bodies and ~ 10,000 targets. - Crossing with the NSL to get observing sequences -(*) Design and test of a global numerical fitting for initial conditions and masses - Evolution toward an operational algorithm (*) : key and most demanding phases 27
Next Meeting 28
Invitation from F. Mignard and P. Tanga Date : 26-27 May, 2005 2-3 June, 2005? 29
Discussions & Actions 30
Actions Nov 04) Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks Accuracy of the centroiding to AF CCDs with gates (DH) schedule : 05/05 Testing recovery strategy + report (FM) schedule : 02/05 Updated simulation with satellites and/or binary asteroids (FM, PT) Schedule : 03/05 Check of the conventions used in the photometric simulation (AC, PT, KM.) Schedule : 02/05 Large blind testing with triaxial ellipsoids (AC, PT, KM) Schedule : 05/05 Availability of a reference list of close approaches (FM) Schedule : 12/05 31
Actions (Nov 04) Simulation of CCD signal for A. Dell'Oro (DH) schedule : 02/05 Introduction of comets in the simulation (FM, PT, HR) schedule : 05/05 32