Astronomy 162 - Stars, Galaxies, & the Universe Richard Pogge

How do we measure the distances to the stars? This lecture
introduces the method of trigonometric parallaxes and the
units of the Parsec and Light Year. Recorded 2006 January 9
in 1008 Evans Laboratory on the Columbus campus of The
Ohio State University.

The "fixed stars" are really in constant motion, but these motions
are too small to see with the human eye in a human lifetime. This
lecture introduces proper motions (apparent angular motion of the
stars in the sky), radial velocities (motion towards or away from
us measured using the Doppler Shift of the star's spectral lines),
and true space velocities, measured by combining three key observables:
the proper motion, radial velocity, and distance to the star. Recorded
2006 January 10 in 1008 Evans Laboratory on the Columbus campus of
The Ohio State University.

How do we quantify stellar brightness? This lecture introduces
the inverse square-law of apparent brightness, the relation between
Luminosity and Apparent Brightness, introduces the stellar magnitude
system, and discusses photometry and the how we measure apparent
brightness in practice. Recorded
2006 January 11 in 1008 Evans Laboratory on the Columbus campus of
The Ohio State University.

How do we measure the masses and radii of stars? This lecture
describes the three basic types of binary stars, and how each are
used to measure the masses of stars. Details of how to measure
stellar radii are beyond the scope of this class, but we briefly
describe the direct measurements of stellar radii.
Recorded 2006 January 12 in 1008 Evans Laboratory on the Columbus campus
of The Ohio State University.

What do the spectra of stars look like, and what can they tell us
about stellar properties? This lecture introduces the idea of stellar
color, gives a brief overview of the history of stellar spectroscopy,
and introduces spectral classification and the main stellar spectral
types OBAFGKMLT.
Recorded 2006 January 13 in 1008 Evans Laboratory on the Columbus campus
of The Ohio State University.

How are all of the observed properties of stars (Luminosity,
Mass, Radius, Temperature and Spectral Type) related to one another?
This lecture introduces the Herzsprung-Russell Diagram, a plot of
Luminosity versus Temperature for stars that is our most powerful tool
for unlocking the secrets of the stars.
Recorded 2006 January 17 in 1008 Evans Laboratory on the Columbus campus
of The Ohio State University.