Origin of the Solar System Spiral Galaxy Beta

Origin of the Solar System Spiral Galaxy Beta Pictoris Star Birth, Orion Nebula Solar Nebula

Formation of the Universe

Origin of the Solar System Historically there have been two competing classes of hypotheses for origin of the solar system. 1. Dualistic or Encounter Hypothesis Le Clerc (Comte de Buffon) in 1745 T. C. Chamberlain in early 20 th century 2. Nebular Hypothesis Descartes 1644 Immanuel Kant 1755 Laplace 1796

Dualistic Hypothesis

Nebular Hypothesis

Beta Pictoris is a young star about 20 million years old that is located 63 light years away. Beta Pictoris This false-color image of the disk surrounding Beta Pictoris was obtained at the European Southern Observatory by blocking direct starlight and imaging the near-infrared light from the disk. The Beta Pictoris disk appears to be a young planetary system in the making. This image supports the standard model of solar system birth, which supposes that planets accrete from a disk of dust and gas surrounding a young star.

At the heart of the Orion Nebula lies a complex of molecular clouds where abundant star formation is occurring today. The clouds are illuminated by a flood of ultraviolet light emitted by four bright stars, collectively called the Trapezium. Orion Nebula, giant stellar nursery ~1600 light years away More than 150 protoplanetary disks have been found in this mosaic of HST images.

At the center of each proplyd (protoplanetary disk) is a T Tauri star. The disks surrounding them are two to eight times the diameter of our solar system.

Solar Nebula with Bipolar Outflow

Nucleosynthesis

Nucleosynthesis Our Sun’s fusion only creates He, need red giant for heavier elements.

Chart of the Nuclides

Nucleosynthesis Elements heavier than Fe created by s- and r-processes in a supernova

Interplanetary Dust Grain In this scanning electron microscope image, all the minerals, organic compounds, and amorphous materials look the same. However, isotopic analysis reveals that some components of this dust actually solidified in interstellar space long before our Sun and its planets formed.