Star and Planet Formation Sommer term 2007 Henrik Beuther & Sebastian Wolf 16.4 Introduction (H.B. & S.W.) 23.4 Physical processes, heating and cooling … (H.B.) 30.4 Gravitational collapse & early protostellar evolution I (H.B.) 07.5 Gravitational collapse & early protostellar evolution II (H.B.) 14.5 Outflows and jets (H.B.) 21.5 Pre-main sequence evolution, stellar birthline (S.W.) 28.5 Pfingsten (no lecture) 04.6 Clusters, the initial mass function (IMF), massive star formation (H.B.) 11.6 Protoplanetary disks: Observations + Models I (S.W.) 18.6 Gas in disks, molecules, chemistry, keplerian motions (H.B.) 25.6 Protoplanetary disks: Observations + Models II (S.W.) 02.7 Accretion, transport processes, local structure and stability (S.W.) 09.7 Planet formation scenarios (S.W.) 16.7 Extrasolar planets: Searching for other worlds (S.W.) 23.7 Summary and open questions (H.B. & S.W.) More Information and the current lecture files: and s:

M51: The Whirlpool Galaxy

Andromeda CO(2-1) Optical

Mid-Infared view of part of Galactic plane

Giant Molecular Clouds Sizes: 20 to 100pc; Masses: 10 4 to 10 6 M sun ; Temperatures: 10 to 15K Superesonic velocity dispersion ~2-3 km/s mainly due to turbulence Magnetic field strengths of the order 10  G Average local densities ~10 4 cm -3 ; Volume-averaged densities ~10 2 cm -3 --> highly clumped material

Sites of Star Formation 1.2 mm Dust Continuum C 18 O N 2 H + Optical Near-Infrared Masses: Between fractions and a few 100 solar masses Densities: Of the order 10 6 cm -3

Properties of Molecular Clouds Type n Size T Mass [cm -3 ] [pc] [K] [M sun ] Giant Molecular Cloud Dark Cloud Complex 5x Individual Dark Cloud Dense low-mass cores Dense high-mass cores >

Orion

The Star-Forming Region W43 Optical Near-Infrared 1.2mm dust cont.

Planck's Black Body

Wien's Law max = 2.9/T [mm] Examples: The Sun T  6000 K  max = 480 nm (optical) Humans T  310 K  max = 9.4  m (MIR) Molecular Clouds T  20 K  max = 145  m (FIR/submm) Cosmic Background T  2.7 K  max = 1.1 mm (mm)

Properties of Main Sequence Stars Mass Sp. Type Lum T eff t MS [M sun ] [log(L sun )] [log(K)] [yr] 60 O x O x O x B x B x A x G x K x M >10 11 } greater than age of universe t MS ~ 5x10 -4 Mc 2 /L = 1x10 10 (M[M sun ])/(L[L sun ]) yr

Sun The easiest to see in night sky and distant galaxies

Star Formation Paradigm

Jupiter Saturn Uranus Neptun Mars Venus Mercury Earth Gas giants Terrestrial planets Sizes not to scale

since 1995: > 200 Extrasolar Planets discovered “Hot Jupiters” High masses Highly elliptical orbits L.R.Cook

Overview planet formation (S.W.) 1.Introduction: Stars – Disks – Planets 2.Protoplanetary Disks: Observations 3.Disk models 1.Accretion, Transport Processes 2.Local Structure and Stability 4.Planet Formation Scenarios 5.Extrasolar Planets

The solar system: some striking facts Planetary orbits are coplanar Planets orbit the sun in the same direction Distribution of Mass and Angular Momentum: Sun Mass: 99.86% but Angular Momentum <2% Age estimation: Sun and Planets have been formed at the same time Extrasolar Planets: large masses, high excentricities, low orbits

Immanuel Kant “Allgemeine Naturgeschichte und Theorie des Himmels” (1755) Solar System is evolving Planets are formed from rotating gas disks

Star Formation – Planet Formation Protostellar / Young circumstellar / Protoplanetary Disk: - Gas / Dust disks around protostars - typical diameter: a few 100 AU Planet Formation: “Byproduct” of Star formation: Collapse of a rotating molecular cloud core (angular momentum <> 0) => Formation of a rotating distribution of the infalling material around the central object (Protostar / Pre-main-sequence Star) Circumstellar Disks - “Reservoir” for mass and angular momentum - Environment + Material for Planet Formation - Evolve in time (structure + composition)

McCaughrean et al. 1996

Young Circumstellar Disks [ => Planet Formation ] => Debris Disks HK Tau IRAS BD betaPic

Star and Planet Formation Sommer term 2007 Henrik Beuther & Sebastian Wolf 16.4 Introduction (H.B. & S.W.) 23.4 Physical processes, heating and cooling … (H.B.) 30.4 Gravitational collapse & early protostellar evolution I (H.B.) 07.5 Gravitational collapse & early protostellar evolution II (H.B.) 14.5 Outflows and jets (H.B.) 21.5 Pre-main sequence evolution, stellar birthline (S.W.) 28.5 Pfingsten (no lecture) 04.6 Clusters, the initial mass function (IMF), massive star formation (H.B.) 11.6 Protoplanetary disks: Observations + models I (S.W.) 18.6 Gas in disks, molecules, chemistry, keplerian motions (H.B.) 25.6 Protoplanetary disks: Observations + models II (S.W.) 02.7 Accretion, transport processes, local structure and stability (S.W.) 09.7 Planet formation scenarios (S.W.) 16.7 Extrasolar planets: Searching for other worlds (S.W.) 23.7 Summary and open questions (H.B. & S.W.) More Information and the current lecture files: and s: