Karen Hamm and Gail Zasowski

 Groupings of stars  Born from the same giant molecular cloud  Young, low stellar density objects  Contain up to several thousand stars M45: The PleiadesM67

 Effects of mass on stellar evolution are directly visible for star clusters  Distances can be calculated more reliably  Better account of stellar evolution, Milky Way evolution and structure, and historical and present star formation Artistic depiction of the evolution of a galaxy

 NASA telescope  High angular resolution and sensitivity  Allows us to view our galaxy in the mid- infrared ◦ Less affected by stellar dust and extinction Spitzer Space Telescope

 Galactic Legacy Infrared Mid-Plane Survey Extraordinaire 360 (GLIMPSE-360) ◦ Spans the far, outer regions of galaxy (65° < l < 265°)  Vela Carina ◦ Spans longitudes of 255° < l < 295°  Outer regions are relatively unexplored for open star clusters Longitudes covered by the GLIMPSE-360 (dark-orange) and Vela Carina (purple) surveys NASA/ JPL Caltech

SAOImage DS9 Individual images scaled to roughly 1° × 1° bins Criteria – Over-density of stars – Similar size and brightness Sample screen shot of SAOImage DS9 program

 Searched for previously published cluster identifications and parameters  Generated color-magnitude diagrams (CMDS) ◦ Color/brightness distribution  The likelihood of the candidates being genuine clusters were sorted based on the clarity of the Spitzer image and the strength and disparity of the CMDs

 Used a modified application of the Rayleigh- Jeans Color Excess method (RJCE; Majewski et al. 2011) to isolate cluster stars  Each cluster CMD represents the stellar sequence of that cluster, as well as foreground and background Galactic features  Cluster stars should share similar foreground reddening  Used the RJCE reddening estimate for each object in the cluster field to search for these distinct stellar sequences  Fit Girardi et al. (2002) isochrones to the stellar population

Restrict E(H-[4.5μ]) range to [0.2 – 0.45]Restrict E(H-[4.5μ]) range to [0.0 – 0.1] ClusterComparison ClusterComparison Cluster

 Identified a number of unknown and uncharacterized open clusters in the outer Milky Way  Derived basic cluster parameters (reddening, metallicity, distance) for objects with well-populated near-IR CMDs  Of one-hundred open clusters identified in the GLIMPSE-360 survey, roughly two- dozen appear to be new candidates

 Presently finalizing a paper to announce these new open clusters and provide parameters for little-studied clusters  Vela Carina as senior-thesis focus

 R.L. Beaton (University of Virginia)  S.R. Majewski (University of Virginia)  B. A. Whitney (University of Wisconsin- Madison)

 Churchwell, E., Babler, B. L., Meade, M. R., et al. 2009, PASP, 121, 213  Whitney, B., Arendt, R., Babler, B., et al. 2008, in Spitzer Proposal ID #60020, (GLIMPSE-360)  Carey, S., Ali, B., Berriman, B., et al. 2008, in Spitzer Proposal ID #50398, (SMOG)  Hora, J., Adams, J., Allen, L., et al. 2007, in Spitzer Proposal ID #40184, (Cyg-X)  Majewski, S. R., et al. 2008, in Spitzer Proposal ID # 40791,40791 (Vela-Carina)  Whitney, B., Benjamin, R., Meade, M., et al. 2011, in Bulletin of the American Astronomical Society, Vol. 43, American Astronomical Society Meeting Abstracts No. 217,  Majewski, S.R., Zasowski, G., & Nidever, D.L. 2011, ApJ, 739, 25  Girardi, L., Bertelli, G., Bressan, A., et al. 2002, A&A, 391, 195