1. NEAT: Very high precision astrometry to detect nearby planetary systems down to one Earth mass F. Malbet, A. Crouzier, M. Shao, A. Léger and the NEAT collaboration updated and presented by A. Quirrenbach GREAT-ESF Workshop. Gaia and Exoplanets: GREAT Synergies on the Horizon. Torino 5-7 Nov 2012

2. Already known planetary systems 1-4 planets per star (o) 136 Prime target stars (x) 2321 Kepler planets (cone) 17 Corot planets (pencils) 471 RV, transit & imaging, +36 HAT +13 WASP planets (cloud) prime hunting grounds for direct imaging & astrometry missions

3. Latest discovery: α Cen Bb Less than 10% of nearby stars have known exoplanets so far ! What has been detected thanks to RV & imaging around the nearby FGK stars?

4. Statistics on exoplanets around the 42 nearby FGK stars

5. Missing low-mass planets ! What types of planets are we missing?

6. Parameter space for high precision astrometry Missing low- mass planets in HZ !

7. Astrometry desired accuracy A = 0.33 (a P /1AU)  (M P /1M  )  (M  /1M ⊙ ) -1  (d/10pc) -1 μ as In order to detect a 1M  planet in HZ @10pc, one needs to detect a signal ≥ 0.3 μ as

8. The prime goal of very high precision astrometry is: ‣ to detect and fully characterize planetary systems ‣ with all components down to one Earth mass ‣ orbiting bright solar-type stars (FGK,V ≤ 9) ‣ in the solar neighborhood (d < 20 pc) with planetary architectures :  similar to that of our Solar System  or any one with Earth mass planets Primary scientific objectives of very high precision astrometry ➥ Key capability: detecting Earth-mass planets in the Habitable Zones of Sun-like stars

9. Simulations of astrometric data

10. Astrometric signal of the Sun located at 10pc  Astrometry works well even with stars 5x more active than the Sun

11. Stellar activity of nearby FGK stars

12. NEAT: a very high precision astrometry mission submitted to ESA Cosmic Mission call for M3 in December 2010 by 70 scientists (full list at http://neat.obs.ujf-grenoble.fr )

16. NEAT planetary targets in the HZ 5 stars at 0.5M  / 70 stars at 1M  / 200 stars at 5M 

18. COSMIC Vision Plan 2015-2025:Theme 1, Section 1.2 ‘‘ On a longer timescale, a complete census of all Earth-sized planets within 100 pc of the Sun would be highly desirable. Building on Gaia’s expected contribution on larger planets, this could be achieved with a high-precision terrestrial planet astrometric surveyor. ’’ We have designed NEAT to be this astrometric surveyor. Conclusion and current status ➠ Science ranked highly by ESA Astronomy Working Group Gaia synergies  NEAT will observe our closest neighbors inaccessible to Gaia  NEAT’s pointed astrometry can investigate interesting cases from Gaia  NEAT will focus on low-mass planets in the Habitable Zone of FGK stars  NEAT can also investigate all nearby A stars and some M stars What next?  Lab demonstration under progress to demonstrate 5 μpixel centroiding  Trade-off between Formation Flying vs deployable boom  Science simulations: double blind test  Extension of science cases: young stars, A stars, M dwarfs, NEO,... All information at http://neat.obs.ujf-grenoble.fr