1. Jan. 12, 2005205 th AAS Meeting, San Diego The HST Survey of the Orion Nebula Cluster Science team: M. Robberto (ESA-STScI), D. Soderblom (STScI), C. R. O’Dell (Vanderbilt), L. A. Hillenbrand (Caltech), M. Simon (Stony Brook), E. D. Feigelson (Penn State), J. Najita (NOAO), K. G. Stassun (Vanderbilt), J. Stauffer (IPAC-Caltech), M. Meyer (Steward), J. Krist (JPL), N. Panagia (STScI), M. Romaniello (ESO), F. Palla (Arcetri), I.N. Reid (STScI), P. McCullough (STScI), R. Makidon (STScI) Home team: E. Bergeron (STScI), M. McMaster (STScI), V. Kozhurina-Platais (STScI), H. McLaughlin (STScI), K. Smith (STScI), W. Sherry (NOAO)

2. Jan. 12, 2005205 th AAS Meeting, San Diego Goals Use deep, simultaneous, high precision photometry to assemble the richest, most accurate, unbiased HR diagram of PMS stars ever made –IMF and its variation with environment –Accretion and disk dissipation vs. environment –Stellar multiplicity vs. disk fraction Discover substantial population of PMS binaries, low mass stars and brown dwarfs down to ~10M J Ha survey of disks, jets, proplyds

3. Jan. 12, 2005205 th AAS Meeting, San Diego Strategy 104 HST orbits, parallel ACS+WFPC2+NIC3 ACS: B  s , V  s , I  s , z  s , H  s  WFPC-2: U  s , B  s , I  s , H   s  NIC-3: J  s , H  s  2 Orientations 100° (36 orbits, Fall 2004) 280° (68 orbits, Spring 2005) Precise tiling pattern allows for full coverage with ACS and WFPC2

4. Jan. 12, 2005205 th AAS Meeting, San Diego Survey area Current on 2-Mass final on ESO-WFI ACS & WFP2: ~0.15sq. deg; NIC3~113-127 sq.arcmin WFPC2: 205.4 Mpix ACS: 904 Mpix NIC-3: 7.4-8.3 Mpix

5. Jan. 12, 2005205 th AAS Meeting, San Diego An ACS strip B, H  -V, I

6. Jan. 12, 2005205 th AAS Meeting, San Diego

7. Jan. 12, 2005205 th AAS Meeting, San Diego

8. Jan. 12, 2005205 th AAS Meeting, San Diego WFPC2 HH

9. Jan. 12, 2005205 th AAS Meeting, San Diego NICMOS FOM increases area surveyed by  1.6. Factor ~2 possible. Galaxies in NICMOS fields

10. Jan. 12, 2005205 th AAS Meeting, San Diego F435W F555W F775W F850LP F658N ACS+NICMOS

11. Jan. 12, 2005205 th AAS Meeting, San Diego NIC3

12. Jan. 12, 2005205 th AAS Meeting, San Diego Two populations: J~12-14 (M type stars) J~18-22 (background objects) NIC-3 photometry

13. Jan. 12, 2005205 th AAS Meeting, San Diego CM diagrams: V vs. V-I

14. Jan. 12, 2005205 th AAS Meeting, San Diego CM diagrams: I vs. I-z

15. Jan. 12, 2005205 th AAS Meeting, San Diego Stellar density

16. Jan. 12, 2005205 th AAS Meeting, San Diego Star counts – I band

17. Jan. 12, 2005205 th AAS Meeting, San Diego Ground-based follow-up Simultaneous UBVIJHK photometry of the ONC –ISPI @ CTIO Blanco 4m: JHK –WFI @ ESO 2.2m: UBVI+Ha Plus CTIO 0.9m, data taken on Jan 1-2, 2005 Optical Multi-object spectroscopy (Hillenbrand) Near-IR spectroscopy (Meyer)

18. Jan. 12, 2005205 th AAS Meeting, San Diego A look at the core region

19. Jan. 12, 2005205 th AAS Meeting, San Diego New objects in the outer regions V H 