Earth Parts: Star Formation and Galaxy Structure

Introduction to NGC 1672

• Presenter: Dr. Johnson-Haas
• Topic: Barred spiral galaxies with a focus on NGC 1672
  • Resembles what the Milky Way might look like from the outside.
  • Located 60 million light years away.

Galaxy Composition and Star Formation

• Components:
  • Stars, diffuse hydrogen and helium gas.
  • Rarefied dust, raw materials for star formation.
• Star Formation:
  • Active in galaxies like the Milky Way.
  • Sun formed in a gas and dust-rich region.
  • Observations possible through telescopes like Hubble and Spitzer.

Molecular Clouds and Star Formation Process

• Molecular Clouds:
  • Composed of hydrogen and helium.
  • Constantly moving, with mass and gravity.
  • Can collapse under their own mass due to disturbances.

Carina Nebula Example

• Dense gas and dust regions lead to star formation.
• Gravitational Collapse:
  • High-density regions collapse into themselves under gravity.
  • Stars form in multiple regions simultaneously.

Orion Nebula and Star Formation

• Observations:
  • Active star-forming region.
  • Over 700 young stars identified.
  • Protoplanetary disks observed.

Eagle Nebula and the Pillars of Creation

• Famous Image:
  • Detailed view of star formation.
  • High-density regions where protostars and planets are forming.
  • Solar wind influences the shape and formation.

Propylids

• Small dense clumps within nebulae.
• Formation Process:
  • Collapse into protostars.
  • Solar winds create bow shocks.

Protoplanetary Disks and Star Systems

• Formation Stages:
  • Disks flatten and organize into star systems.
  • Planets form by accretion of dust and gas.
  • Larger bodies clear their orbital paths.

Example Systems

• Formalhaut:
  • Young star with debris ring.
  • Discovery of exoplanet, Formalhaut b.
• HL Tauri and TW Hydrate:
  • Rings indicate planet formation.
  • Observations help understand solar system history.