Early Jupiter Formation

Kruijer et al. (2017)

Wei Zhu

2019-11-21

Image from  Maruyama & Ebisuzaki (2017)

A simple picture of

planet formation & evolution

Snow line

Meteorites, Chondrites, CAIs

Hoba meteorite@Namibia (~60 t)

  • Iron meteorites: Fe & Ni rich, cores of planetesimals.
  • Chondrites: non-metallic meteorites, no melting or differentiation.
  • Ca-Al-rich Inclusions (CAIs): sub-mm/mm, found in Carbonaceous chondrites

Genetically distinct populations?

Molybdenum & Tungsten:  high melting temperature elements

Hafnium-Tungsten dating technique \(\rightarrow\) core formation time

  • \(^{182}\)Hf \(\rightarrow\) \(^{182}\)W: half-life 9 Myr.
  • Hf: lithophile (aka, rock-loving)
  • W: siderophile(aka, iron-loving)

Accretion time

Al fractions

The story...

Pollack et al. (1996)

Suzuki et al. (2016)

(see Herman, Zhu, & Wu 2019 for the radius distribtuion)

OB120026L:

Core accretion theory of Jupiter formation?

Jupiter preventing super-Earth formation?

Cold Jupiters

Super Earths

22 from Kepler (triangles) + 39 from RV (squares)

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019, Herman, Zhu, & Wu 2019)

Giant planet-metallicity correlation

  • Giant planet formation is generally inefficient

Fischer & Valenti (2005)

f \propto Z^2 \propto N_{\rm Fe}^2

A problem for pebble accretion?

Figure adapted from Penny et al. (2019)

  • Typically super Earths
  • ~3 per system
  • Gas fraction: a few %.
  • If MMSN is the standard nebula model:
    • SS evidence requires early Jupiter formation.
    • Inner-outer correlation requires later giant planet formation.

Early Jupiter Formation

By Wei Zhu

Early Jupiter Formation

Paper discussion at the Thursday group meeting

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