1. The Birth of Stars and Planets in the Orion Nebula K. Smith (STScI)

2. Orion (the hunter)

3. Why Orion? Closest massive star forming region (450pc) (there are closer low mass star forming regions) Relatively young (1Myr) Now believed that our Sun started life in such an environment

4. Giant molecular clouds Found throughout galactic plane Are the sites of star formation Dame et al

5. Star formation…

6. Stars form in clusters and groups NGC 346, SMC Pleiades NGC 1850, LMC

7. Orion + CO

8. Barnard loop Rosette Nebula Orion and surroundings in the visible NGC 1741 NGC 2022 Witch Head Nebula

9. IRAS 100 micron image …and in the far-infrared

10. Stellar density in Taurus vs. Orion 14.6´ × 15.1´ @140pc = 0.59pc ×0.61pc 7´ × 7´ @450pc = 0.91pc ×0.91pc

11. Massive stars Disperse the cloud Ionise the gas May disrupt low mass star disks Burn out quickly

12. Hot stars, ionized gas and dusty nebulae trace star formation NGC2024 Horsehead NGC1976 M42 NGC1977

13. Massive stars Disperse the cloud Ionise the gas May disrupt low mass star disks Burn out quickly Low mass stars Have disks and accrete material for several million years Launch jets Form planetary systems

14. The current paradigm (Low Mass Objects) Cloud collapse 10 4 yr Disk/wind 10 5 yr Planetary system 10 9 yr10 7 yr Low-mass binary

15. HH 30 Sargent & Beckwith 1987, Ap. J., 323, 294. 13 CO 2-1 4.4-5.8 km s -1 1000 AU HL Tau XZ Tau HH 30 5000 AU Mundt et al. 1990, A&A, 232, 37. SII 6717 Å 3.5m Calar Alto Disk / jet “standard” model e.g. Lin et al, 1994, Ap. J., 435, 821. Ray et al. 1996, Ap. J., 468, L103. HST images of disks provided "proof"

16. Disks in the IR (NICMOS/HST)

17. HK Tau B C. Koresko, Ap.J.Lett. 1998 Adaptive optics on Keck

18. Jets

19. Jets from binaries

20. Treasury program 104 HST orbits, parallel ACS +WFPC2 +NIC3 ACS: B (420s), V (385s), I (385s), z (385s), Ha (340s) WFPC-2: U (2  400s), B (80s), I (10s), Ha (400s) NIC-3: J (5  256s), H (4  192s) 2 Orientations 100° (35 orbits, Fall 2004) 280° (69 orbits, Spring 2005) Precise tiling pattern allows for full coverage with ACS and WFPC2 PI : M. Robberto

21. Mapping strategy

22. Fall campaign on 2-Mass

23. On ESO Optical ImageOn 2MASS JHK Color Mapping strategy

25. Motivation Apart from pretty picture, what do we learn? IMF - the distribution of masses HR diagram - test models of stellar evolution Reaction of disks to different environments Binary properties

26. For every massive star (>10Msol)… there are many hundreds of lower mass stars Hillenbrand & Carpenter, 2000

27. The HR diagram Hillenbrand 1997

28. PSF subtraction reveals close binary companions Companion is 0.45" from the primary, flux ratio ~6 mag I band Original images, visits 49, 4a, 4c final drizzled

29. Disks in the Orion environment

30. 114-426: giant dark silhouette disk

31. IR emission from Disks Chiang & Goldreich 1997, Ap. J., 490, 368. Superheated surface layer with small grains produces infrared. “Black” interior produces millimeter-wave emission.

32. The cluster core

33. The core region

35. Proplyds 400 AU 2000 AU Section of the Orion Nebula 114-426 183-405 206-446182-413 O’Dell & Wen 1992, Ap.J., 387, 229; McCaughrean & O’Dell 1996, AJ, 108, 1382.

37. Disk evaporation

38. 6 – 13.6 eV UV photons Disk evaporation

39. 6 – 13.6 eV UV photons Disk evaporation

40. 6 – 13.6 eV UV photons Disk evaporation

41. 6 – 13.6 eV UV photons Disk evaporation

42. 6 – 13.6 eV UV photons > 13.6 eV photons Disk evaporation

43. 6 – 13.6 eV UV photons > 13.6 eV photons Disk evaporation

44. 6 – 13.6 eV UV photons > 13.6 eV photons Stellar wind Disk evaporation

45. 6 – 13.6 eV UV photons > 13.6 eV photons 6 – 13.6 eV UV photons > 13.6 eV photons Stellar wind Disk evaporation Disks are evaporated by FUV photons

46. Animation showing HH502 motion between Aug 2002 and Nov 2004 (2.25 yr)

48. To sum up… The treasury programme is the widest and deepest survey yet made of the Orion nebula cluster The main goals; Determine the IMF for low mass stars in Orion Obtain a precise HR diagram to test models Observe disks in a ‘hostile’ environment - believed to be similar to the birth environment of the Sun