Institute of Astronomy

Galaxies Viewed as Collections of Individual Stars

SpeakerTalk DateTalk Series
Professor Julianne Dalcanton, University of Washington8 March 2012The Eddington Lectures


In extragalactic astronomy, we routinely observe galaxies in broad-band filters, and then interpret the resulting spectral energy distribution to learn about the galaxies’ masses, star formation rates, ages, and metallicities. The fidelity of this interpretation relies on having a detailed understanding of the stellar populations within the galaxy, and on accurately characterizing the luminosities and colors of the billions of stars which contribute to a galaxy’s light. In this talk I will discuss several large programs which use the Hubble Space Telescope to resolve millions of the most luminous stars in nearby galaxies. I will highlight results using near infrared observations, focusing on implications for the evolution of stars and the integrated NIR light of distant galaxies.