Huachuca Astronomy Club—Speakers

Dr. Lucas Macri, NOAO

"Scientific Observations through the Hubble Telescope"


Dr. Lucas Macri. (Photo by Mark Levy, Herald/Review.)

Synopsis: On June 29, 2007, Dr. Lucas Macri, from the National Optical Astronomy Observatory (NOAO), described observations through the Hubble Space telescope to help determine a good value for the Hubble Constant, which in turn enables astronomers to measure distances more accurately in our universe.
National Optical Astronomy Observatory (NOAO)

View the Sierra Vista Herald newspaper article here.


Biography: Lucas Macri was born in Buenos Aires, Argentina, in 1972. He attended the Massachusetts Institute of Technology, where he graduated with a B.S. in Physics in 1995, and Harvard University, where he obtained a Ph.D. in Astronomy in 2001. He has been a Hubble and Goldberg post-doctoral fellow at the NOAO in Tucson since 2002.

He joined NOAO as a Hubble and Goldberg Post-Doctoral Fellow in September 2002, at which time he was offered a follow-on Goldberg fellowship to start in the fall of 2005. The primary science goal of his fellowship is the characterization of unresolved systematic effects in the Cepheid Distance Scale. As part of his PhD Thesis, he was involved in a large-scale synoptic survey of M33, which resulted in the discovery of over 600 Cepheids in that galaxy. Lucas is currently carrying out follow-up observations of these variables using the WIYN and Gemini North telescopes. Once completed, these observations will yield accurate BVIJHK magnitudes that will be used to characterize the dependence of Cepheid luminosity and temperature on metal content. An interesting by-product of this observational program are deep optical and near-infrared color-magnitude diagrams, which he intends to use for stellar population studies. Lucas is also involved in a collaboration that has recently observed two fields in the "maser galaxy" NGC 4258 with the Advance Camera for Surveys on HST to obtain a robust and accurate absolute calibration of the Cepheid Distance Scale. Lucas is also interested in the application of the near-infrared Tully-Fisher relation to map peculiar velocities in the nearby Universe, to obtain an independent measure of Omega (matter) and study nonlinear galaxy biasing scenarios. The first step in this long-term project is the completion of the 2MASS Redshift Survey, in which he is a collaborator.



Speakers Index