NURO currently has one key project, Searching for O-type Binaries in Clusters . The PI's for this project are Phil Massey of Lowell Observatory and Kathy Eastwood of NAU.

Scientific Motiviation: The most absolutely fundamental property of a star is its mass, and yet for high-mass stars there is a long-standing systematic difference between the masses determined from stellar evolutionary models, and those found from stellar atmosphere models. For the hottest stars, this “mass discrepancy” may amount to a factor of two or more. The problem was originally identified by Herrero et al. 1992; for a recent reexamination of the problem, see Massey et al. 2005.

Overall observing plan: This project seeks not only to resolve this discrepancy by using high-mass binaries, but to provide feedback to theoreticians to determine the specific areas in which the models need improvement. The first goal is to identify eclipsing binary systems photometrically, using frequent imaging of OB associations and clusters known to contain a wealth of high-mass stars, both in the Milky Way and in the Magellanic Clouds.  After the variables are identified, radial velocity studies of the newly-found systems will yield orbit solutions.  High signal-to-noise data will be obtained for some systems in order model the stellar atmospheres. For more details, see Phil's site.

What NURO members can do: In 2006, NURO observers can contribute by helping to monitor Cyg OB2 at the Lowell 31-inch telescope. Click HERE for details.