Astronomy 162 - Stars, Galaxies, & The Universe

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.

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 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.