ASTR 1150 Lecture Notes - Lecture 10: Hubble Deep Field, Edwin Hubble, Irregular Galaxy
Document Summary
Astr 1150 - lecture ten: galaxies and star clusters. Originally, other galaxies were thought to be large groups of stars within the milky way. Early telescopes not powerful enough to resolve individual stars. Spiral galaxies were thought to be solar systems in formation. Again, telescopes could not resolve the stars in galaxies. In 1924, edwin hubble measured the distance to a cepheid variable in andromeda. He calculated a distance of 900,000 ly. Far outside the bounds of the milky way (remember it was only about 100,000 ly across) Most recent observations of galaxies occur in what appear to be empty regions of space. A very small portion of the sky. He had access to the most powerful telescope of the day. Flat, spinning disk (typically with younger stars) Sb lots of arms, lots of bulge. The milky way is probably a sbb galaxy. Strong evidence for a bar through galactic bulge. Masses between 1 billion and 1 trillion m .
