Variable Stars as Precision Distance Indicators: From the Local Group to the Hubble Constant

Variable stars have been used as distance indicators for the past 100 years, but it is only in the last few years that we have truly reached the era of “precision” distance indicators. In this talk, I will discuss my work using mid infrared observations of Cepheids and RR Lyrae in the Milky Way, Local Group and beyond, to measure the Hubble constant in the Carnegie Hubble Program, Carnegie RR Lyrae Program, and the recently started CHP2.

Additionally, I will discuss how these variables can be used in stellar cartography, making precise 3 dimensional maps of our nearest neighbors, through the SMHASH (Spitzer merger history and shape of the Galactic Halo) program and my recent work mapping the Magellanic Clouds.

Cody Hall

Vicky Scowcroft (Carnegie Observatories)

January 23, 2015
14:00 - 15:00