1. John Bally Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado, Boulder Recent Developments Recent Developments in Stellar and Planetary System Formation Formation

2. Introduction Introduction Star Formation: The fundamental cosmic (baryonic) process Determines cosmic fate of normal matter Star Formation Galaxy formation, evolution, IMF Elements (He => U) Clusters black holes (AGN, stellar) Light, K.E. of ISM Planet formation Conditions for life

3. Where planets also form Giant Molecular Cloud Core Gravitational Collapse & Fragmentation Rotation & Magnetic Fields Raw material for star birth Proto-stars, proto-binaries, proto-clusters Accretion disks, jets, & outflows Shrink size by 10 7 ; increase density by x 10 21 ! Star Formation Star Formation Planets C. Lada Most may form in clusters!

4. Star-Formation: SF occurs in Giant Molecular Clouds (GMCs): Decay of turbulence + Gravity +  B Collapse => disks, jets => stars, planets Fragmentation: Non-hierachical multiples: disintegration Dense (mostly unbound) clusters: ~ 10 3 - 10 5 pc -3 90% of stars born in OB associations: Multiple SN Superbubbles => inject short-lived isotopes GMCs OB *s superbubbles Supershells / ringsgravity 20 - 50 Myr      Galactic 'ecology'

5. NGC 1333 IC 348 IRAS 03235+3004

6. M.Bate

7.  S  O 

8. Spitzer IRAC

9. HH 46/47 HST 1997 - 1994

10. HH 46/47 HST 1997 - 1994

11. Irradiated jets in  Car (Tr 14)

13. The Orion Star Forming Complex Wei-Hao Wang

15. Infrared view of winter sky (10 - 120  m)

16. The Orion/Eridanus Bubble (H  ): d=180 to 500pc; l > 300 pc Orion OB1 Association: ~40 > 8 M stars: ~20 SN in 10 Myr 1a (8 - 12 Myr; d ~ 350 pc)) 1b (3 -6 Myr; d ~ 420 pc) 1c (2 - 6 Myr; d ~ 420 pc) 1d (<2 Myr; d ~ 460 pc) Ori (< 3 Myr) Barnards's Loop Eridanus Loop

17. Orion B Orion A Orion Nebula Orion Molecular Clouds 13 CO 2.6 mm

18. 20

20. Orion below the Belt: Horsehead Nebula Orion Nebula NGC 2024 (OB1 d)  Orionis (  c) NGC 1977  Ori NGC1980: Source of  Col + AE Aur ; V ~ 150 km/s runaways, 2.6 Myr ago NGC 1981 Ori OB1c Ori OB1d

22.  NKL  Trapezium  OMC1-S (L = 10 5 L o t << 10 5 yr) (L = 10 4 L o, t < 10 5 yr) (L = 10 5 L o t < 10 5 yr ) OMC 1 Outflow   t = 3,000 yr) Orion Nebula

24. Trapezium cluster Proper motions: Van Altena et al. 88 V esc ~ 6 km s -1 2.6 1.8 5 2.5

25. Orion BN/KL H 2 NICFPS APO 3.5 m First light 21 Nov 04

28. 0.5 – 2.2  m 10 4 AU

29. 11.7  m Gemini S TReCS 10 4 AU

30. OMC1 H 2 fingers

31. High-velocity stars: I, BN, n (Gomez et al. 2005) BN: V~ 30 km s -1 I: ~ 13 km s -1 n: ~ 20 km s -1

32. d253-535 in M43 UV photo-ablation of disks & planet formation:

33. Orion Nebula: Disks seen in silhouette

34. HST 16 HST 10 HST 17 Irradiated proto-planetary disks:

35. Anatomy of a planetary system forming in an OB association

36. Disk mass-loss: UV Radiation => heatimg = > Mass – loss  ~ 1 Myr r > GM / c 2 ~ 40 AU for Soft UV (91 < < 200 nm) ~ 5 AU for ionizing UV ( < 91 nm) (for Solar mass) Self-irradiation by central star vs. External irradiation by nearby massive star: L self (UV) / 4  d * 2 = L external (UV) / 4  d OB 2 L external (UV) ~ 10 49 photons / sec L self (UV) ~ 10 40 - 10 43 photons / sec

37. Impacts of the environment: Life of a massive star ~ 3 to 40 Myr ~ planet formation time-scale Clustering, multiplicity: - Close-encounters - Truncate, shock-heat disks UV radiation: - External + Self => Mass-lost in ~ few Myr UV dose: 10 42 – 10 45  t (  sec -1 ) Main-sequence star (3 – 30 Myr) Blue-supergiant (< 10 6 years) Supernova (1 year) Massive star winds, Supernovae: - Inject short-lived isotopes: 26 Al, 60 Fe

38. UV => Fast Growth of Planetesimals: Grain growth => Solids settle to mid-plane UV => Remove dust depleted gas => High metallicity in mid-plane Gravity => Instability => 1 - 100 km planetesimals - Fast Formation of 1 to 100 km planetesimals

39. Growing grains : Orion 114-426 (Throop et al. 2001)

41. Oldest meteorites: (CAIs: 4,567.6 Myr old = 0 ) Chondrules: +2 to 4 Myr 26 Al => 26 Mg (t 1/2 ~ 0.7 Myr) 60 Fe => stable elements (t 1/2 ~ 1.5 Myr) => Solar System formed in Orion-like OB association SN within few pc, few Myr of forming Solar System Supernovae: Supernovae:

42. Conclusions Conclusions Most stars form in Orion-like regions - Sibling star interactions - Jets => halt star formation Proto-planetary disks processed by UV - Gas lost in few x 10 6 years - Grain growth + sedimantation + UV => Prompt planetesimal formation Massive Stars: - Mutual interactions => high velocity stars (BN) => explosive outflows - HII regions => halt star formation - Supernavae: => Inject 60 Fe, 26 Al, …

43. The End