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Project Progress

Searching for Main Belt Comets with the Pan-STARRS 1 Survey Telescope

The Pan-STARRS1 (PS1) project is an all-sky survey using a 1.8-meter telescope on Haleakala in Hawaii. We have developed a system (“stamp store”) for storing and archiving intermediate static-sky subtracted images for transient detections, like asteroids. Normally, these images would be deleted, but we need them to apply specialized photometry to search for comet-like activity. This system will archive and organize approximately 40 terabytes of data over the 3.5-year lifetime of the project. Our approach for searching for MBC activity is based on searching for the brightest segment around a point source, and it is incorporated into a data processing pipeline that automatically polls new PS1 asteroid detections, performs specialized photometry on images in the above stamp store, and accumulates statistics used in deciding whether an object is an MBC candidate.

We have been engaged in a search for more Main Belt Comets (MBCs) in data from the newly operational Pan-STARRS1 (PS1) survey telescope on Haleakala. This is the first year that PS1 has been running steadily, producing terabytes of image data and hundreds of thousands of asteroid detections. Using our specialized pipeline, we have been analyzing Main Melt asteroid detections for signs of cometary activity (see Figure). We have found what appears to be a statistical excess of activity in the expected direction as opposed to unphysical directions. Over the next year, we will continue mining PS1 data and following up candidates with time on other telescopes, for which we have significant allocations. Using our specialized pipeline designed to search postage stamp images of asteroids for tail activity, we have been analyzing Main Melt asteroid detections for signs of cometary activity (see figure). In a preliminary batch of data from the spring of 2010, we have found what appears to be a statistical excess of activity in the expected direction as opposed to three unphysical orthogonal directions, yielding 5 to 10 potential MBC candidates. Over the next year, we will continue searching PS1 data, improving and extending our search algorithms. We will also follow up candidates with time on other telescopes, for which we have been allocated 14 hours of CFHT time, 6 nights of UH 2.2m time, and 6 nights of SMARTS 1.3m time. In deeper exposures, we hope to see direct evidence of activity that was detected statistically in PS1.

This project will eventually yield a full measure of the MBC population, will help determine the prevalence of water in the inner Solar System, and will provide likely provide targets for possible NASA missions to visit these bodies.