L01 Time Scales

L01 Time Scales#

Week 1, Tuesday

Notebook: 01-Timescales.ipynb (see next item)

Slides shown in class: L01-W1-Tu-timescales.pdf

Material covered and references#

We discussed the administration of this course. Please refer to the Course Syllabus for details.

We listed all the elements of physics that are important to understand the structure of a star.

We made order of magnitude estimates of various timescales.

  • KH timescale

  • Nuclear timescale

  • Dynamical timescale (We’ll finish this on Thursday!)

Micro-objectives:

  • I can calculate the sun’s lifetime based on the chemical yield of a combustion reaction

  • I can calculate the sun’s lifetime based on the gravitational contraction

  • I can explain the yield from nuclear reactions and can calculate the sun’s lifetime based on the H-burning nuclear yield.

  • I can explain the approximation we use the estimate the hydrostatic timescale and I can calculate the sun’s hydrostatic’s timescale.

  • I can explain the consequence of the large difference between the hydro and nuclear timescale (and the resulting approximation we can make about the equations that describe stellar structure).

In the textbooks:

  • Leblanc 2.5, 6.1, 6.5

  • McD 2.4, 3.3

  • Hanson 1.3

  • Kip 2.4, 3.3, 4.4