Program: GN-2006A-Q-70

Title:Classifying Discoveries from a Large-area Near-infrared Proper Motion Survey
PI:J Davy Kirkpatrick
Co-I(s): Dagny L Looper, Roc M Cutri, Adam J Burgasser

Abstract

Using multi-epoch 2MASS data, we have conducted a very large area ($\sim$6000 square degrees) near-infrared proper motion survey. The goal of this survey is to search for nearby, optically faint/invisible sources that would have been missed by previous optical motion surveys. Earlier near-infrared searches for nearby stars have relied solely on photometric criteria that are heavily biased toward solar-age, solar-metallicity stars and brown dwarfs. Such color-based surveys lead to an incomplete and biased census of the Solar Neighborhood. On the other hand, dwarfs that are nearby or have halo kinematics are generally distinguished by high proper motions. Using our new survey we have amassed a list of 159 proper motion stars ($\mu \ge 0.2$ arcsec/yr, $J \le 16.5$) that are invisible on optical blue and red sky survey plates. We wish to obtain classification spectra of a subset of these (27 objects) to provide ample statistics on the makeup of this sample. Knowledge of heretofore missed classes of objects can lead to better photometric selections in the future. The only known halo brown dwarf (2MASS 0532+82) was discovered serendipitously, our discovery of a few more halo brown dwarfs would provide much greater insight into this population.

Publications using this program's data