Solar System Working Group. 5th Meeting -----

Transcription

1 Solar System Working Group 5th Meeting F. Mignard 1

2 Attendants - Joos de BRUIJNE - Alberto CELLINO - Aldo DELL'ORO -Marco DELBO -Mikael GRANVIK - Daniel HESTROFFER -Sylvie JANCART - Mikko KAASALAINEN - Claes-Ingvar LAGERKVIST - Kari LUMME -François MIGNARD - Karri MUINONEN -Paolo TANGA - William THUILLOT - Johanna TORPPA - Jenny VIRTANEN - Stefan WOLFF - Teemu LAAKSO 2

3 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 GDAAS and algorithm delivery Set guidelines for the next six months 3

4 AGENDA 27/05 09h00 Status of the GAIA mission. Current activities F. Mignard 09h30 Organisation of the WG. Review of actions F. Mignard 10h00 The Gaia database : status, content, use J. de Bruijne 10h30 Coffee 11h00 Error model in the AF fields D. Hestroffer, F. Arenou, C. Babusiau 11h30 Update of the simulation : general new needs 12h00 Update of the simulation : photometry F. Mignard P. Tanga 12h30 lunch break 13h45 Visit of the Observatory grounds and group picture 4

5 AGENDA 27/05 14h30 Determination of the size with Gaia data A. dell Oro, M. Delbo 15h00 Photometric activities. Blind testing A. Cellino 15h30 Physical properties of asteroids from Gaia data M. Kaasalainen 16h00 coffee 16h15 Physical characteristics with spherical harmonics J. Torppa 16h45 Asteroid photometry blind test: initial conditions K. Muinonen, J. Virtanen, F. Mignard 17h15 Lightcurve and photocenter analysis of ellipsoidal bodies with the Lommel-Seeliger scattering law Kari Lumme 17h45 Asteroid taxonomy C. I. Lagerkvist 18h15 End of the first day 5

6 AGENDA 28/05 09h00 Detection of moving objects : first results S. Wolff, F. Mignard 09h30 Initial orbits from GAIA observations with statistical ranging J. Virtanen, K. Muinonen, M. Granvik, T. Laakso: 10h00 Least-squares orbit computation using GAIA observations M. Granvik, K. Muinonen, J. Virtanen, T. Laakso 10h30 Coffee 11h00 Asteroid orbit improvement J. Berthier, D. Hestroffer 11h30 Asteroids radial velocity measurements D. Hestroffer D. Katz, A. Doressoundiram 12h00 Discussion, summary, actions All 13h30 End of the meeting 6

7 Status of GAIA 7

8 GAIA ESA Final presentation of the two System Level Technical Assistance contracts on 2-3 March no major revision of the main concepts significant change in the FOV layout for MBP and spectro reassessment of the thermo-mechanical stability Phase B1 started in April 2004 for one year A launch date of 2010 implies start of B2 in April 2005 decision to be taken by the head of Scientific Projects and the Director of Science depends on : > the funding status of the whole science program > the technical status of Gaia after phase B1 current funding only allows to stick to the SPC schedule (2012) But new Ministerial Conference in May-June

9 GAIA ESA In preparation of this meeting : the ESA Director General would ask for an increase in level of resources increase by 25% in 3 years of the resources for the mandatory program Two specific reasons the restitution of the Eddington planet/starquake-seeking mission cancelled in November 2003 ia replacement for the loss of the first European astrobiological lander, Beagle2, in late December 2003 More specifically The AWG is asked to comment on the following options: Implementing Eddington, Bringing GAIA forward as far as technical constraints will allow, Implementing SMART-3 as a pathfinder for a Darwin-like interferometry mission in the next decade, Provision of payloads for non-esa missions (in US or elsewhere), Any realistic concept which gathers the consensus of the AWG (e.g. preparation for next generation high energy astrophysics missions). 9

10 GAIA Schedule Acceptance Technology Development Design, Build, Test Launch Observations Analysis Catalogue 10

11 GAIA Summary Schedule-2010 Launch ID Task Name 1 Technology Developments 2 Payload Technology 3 Ground Verification (completed) 4 P/L Data Hand. Electr. 5 Optimum Compression Algorithm 6 RVS Optmisation 7 CCD 8 CCD Validation Activity (completed) 9 CCD & FPA Techno. Demonstrators 10 Optics 11 High Stability Opt. Benches (completed) 12 Payload Mirrors 13 Active Pointing Control 14 Laser Metrology & Active Optics 15 Inch-worm mechanism 16 Data Base Activities 17 GAIA Date Base/Algorithm Integr.Dev. 18 Data Base Architecture (completed) 19 Spacecraft Technology 20 mn Feep Qualification (1/3 lifetime test) 21 mn Feep Qual. Finalisation (2/3 lifetime test) 22 Large Size Deployable Sunshield 23 Phased Array Antenna (completed) 24 GAIA Definition Phase 25 Competitive Definition Phase 26 Tech. Assist. Contr. #1-Alenia (compl.) 27 Tech. Assist. Contr. #2-Astrium (compl.) 28 Definit. Study #1 (Phase B1)-Alenia 29 Definit. Study #2 (Phase B1)-Astrium 30 Implementation Phase (with Industry) 31 Phase B2 32 Phase C/D 33 Launch Campaign 34 Launch H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 H1 H2 1 15/02 06/12 29/02 03/ days 02/12 31/03 01/08 29/04 10/09 11/02 01/05 31/07 02/01 29/07 17/02 06/04 02/09 28/02 01/08 25/01 06/05 31/08 20/01 15/09 03/09 31/07 04/12 02/04 05/12 05/04 02/04 31/03 02/04 31/ days 02/05 28/04 01/05 26/05 28/07 Phase B2 start line 11

12 Design 12

13 Relative position of the FOV's, Old design (baseline for simualtions) Spin axis Sequence P = 6h Observation t = 0 Spectro 38 Spectro/MBP + 38 mn mn AF1 AF mn Spectro Astro 1 (PFOV) etc Astro 2 (FFOV) Scan direction 13

14 Relative position of the FOV's Current design under study Sequence Spin axis P = 6h t = 0 Observation + 28 mn + 78 mn AF1 Spectro AF Astro 1 (PFOV) mn etc AF1 Spectro/MBP Astro 2 (FFOV) Scan direction 14

15 Focal plane ~ 800 mm, 0.96 deg Astro Field Cell size : 49 x 60 mm mm 0.74 deg ASM1 ASM2 transit AF1-11 BBP CCD size : 45 x 59 mm k x 2 k Pixel size 10 x 30 µm 2 = 44 x 133 mas 2 TDI : ms Airy (along) 103 mas Integration time : 3.3 s For ASM : 1.9 s FOV 1 FOV 2 15

16 Astro and Spectro Focal planes Old design (baseline for simualtions) 2 = 120s = 74 mm ~ 750 mm, 0.92 deg MBP1 MBPSM mm 600 mm 0.74 deg RVS mm RVSM ASM1 AF1-11 BBP ASM2 FOV 1 FOV 2 MBP2 V =19% mm 16

17 MBP Fields (new design) MBP 2.1 = 125s = 88 mm MBP 2.1 = 125s = 88 mm SM/NEO R V S mm mm R V S CCDs Scan MBP : 800 x 1960 pxs Pixel size 10 x 15 µm x 1.35 arcsec 2 Full read-out or windowing mode Optical axis Integration time MBPSM ~ 6.7s MBP ~ 12.5 s RVS FOV 17

18 Gates and observation of planets Note of F. Safa, 26/02/04 Electronic control of the integration time No gate : integration over τ = 3.3 s over AF_k Gates giving τ 1 = τ/2, τ 2 = τ/4, τ 3 = τ/8... Saturation level e - : V = 12 (G2V), 13.7 (M6V) Jupiter ( ρ ~ 20 " = 400 px/al) gives 2.8 x 10 6 e - /px ::: highly saturated Observable with gate_4 But more important : how close a star or a satellite are observable? saturation disappears at 3 pixels from the edge (130 mas, ρ/130) background noise less than V = 10 px (ρ/40), V = 100 px (ρ/4) 18

19 The Solar System Working Group 19

20 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

21 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

22 Core members M. Carpino A. Cellino A. Dell'Oro M. Delbo E. Dotto D. Hestroffer E. Hoeg S. Klioner F. Mignard K. Muinonen M. Rapaport P. Tanga W. Thuillot E. Zappala S. Wolff Membership Associates C. Bailer-Jones J. Berthier F. Colas A. Doressoundiram W. Evans C. Fabricius P. Hjorth U. Jorgensen C.I. Lagerkvist M. Kaasalainen R. Michelsen A. Morbidelli J.M. Petit V. Vansevivius J. Virtanen 22

23 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

24 Review of pending actions 24

25 Actions (Nov 03) Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks :: it worked fine Information sheets for the GAIA website Trojans, (AC) KBOs (JMP), Minor planets, NEOs (FM) : completed Simulation of moving objects with origin at Gaia around L2 (FM) schedule : 12/03 :: completed Extended the accuracy of the centroiding to AF CCDs (DH) schedule : 02/04 ::: report during this meeting Introduction of moving objects in the GDAAS simulator (FM, PT) schedule ( a first version): 04/04 :: completed Operational testing of moving objects in GDAAS (SW, FM) schedule ( a first version): 04/04 :: report during this meeting 25

26 Actions (Nov 03) Blind testing of the determination of physical parameters Simulation : 01/04 (FM, KM, PT) Solution : 05/04 (MD, EZ, AC) ::: report during this meeting Assessement of the orbit improvement from Gaia data only on known asteroids schedule : 05/04 : (JB, DH, JV, KM) ::: report during this meeting Density of minor planets in small test fields over 5 years (FM) schedule : 05/04 : pending Tutorial document on scattering law (KM) schedule : 02/04 : completed Implementation of the new error model in the simulation (FM) Schedule 02/04 (FM) :: completed (but not satisfactory) Preliminary orbit solution for short interval of time (JV, KM) schedule : 05/04 26

27 Software delivery to GDAAS revised schedule 25: 4-01-C minor planet motion (Mignard): expected Jul03 A version will be delivered before Summer 2004 with the current assumptions about the sampling and the transmitted windows 26: 4-02-C minor planet cross-identification (Mignard): expected Sep2004 This remains acceptable 27: 4-03-C minor planet orbital solution (Mignard): expected Sep04 At the moment, the algorithm is being tested on the simulation of the SSWG and is far from being operational. Then, it must be turned into an algorithm able to work with the assumptions and interface of GDAAS. I do not think that this could be done by the end of Better view after the next SSWG in May. 27

28 Next Meeting 28

29 Invitation from Sergei Klioner Date : November

30 Discussions & Actions 30

31 Actions (May 04) Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks Accuracy of the centroiding to AF CCDs for moving objects (DH) schedule : 07/04 Testing of moving objects in GDAAS (SW, FM) schedule ( a first version): 07/04 Updated simulation + data file available to all (FM, PT) Schedule : 06/04 Large blind testing with triaxial ellipsoids (AC,...) Schedule : 06/04 Investigate the introduction of complex shape () Schedule : 31

32 Actions (May 04) Comet observation with Gaia () schedule : 11/04 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 : 10/04 32