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Near-nucleus photometry of comets using archived NEAT data |
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| Authors: | Michael D Hicks Raymond J Bambery Priya Kollipara |
| Institution: | a Jet Propulsion Laboratory, JPL MS 183-501, 4800 Oak Grove Drive, Pasadena, CA 91109, USA b Jet Propulsion Laboratory, JPL MS 168-527, 4800 Oak Grove Drive, Pasadena, CA 91109, USA c Department of Astronomy, California Institute of Technology, 105-24 Caltech, 1201 East California Blvd., Pasadena, CA 91125, USA |
| Abstract: | Though optimized to discover and track fast moving Near-Earth Objects (NEOs), the Near-Earth Asteroid Tracking (NEAT) survey dataset can be mined to obtain information on the comet population observed serendipitously during the asteroid survey. We have completed analysis of over 400 CCD images of comets obtained during the autonomous operations of two 1.2-m telescopes: the first on the summit of Haleakala on the Hawaiian island of Maui and the second on Palomar Mountain in southern California. Photometric calibrations of each frame were derived using background catalog stars and the near-nucleus comet photometry measured. We measured dust production and normalized magnitudes for the coma and nucleus in order to explore cometary activity and comet size-frequency distributions. Our data over an approximately two-year time frame (2001 August-2003 February) include 52 comets: 12 periodic, 19 numbered, and 21 non-periodic, obtained over a wide range of viewing geometries and helio/geocentric distances. Nuclear magnitudes were estimated for a subset of comets observed. We found that for low-activity comets (Afρ<100 cm) our model gave reasonable estimates for nuclear size and magnitude. The slope of the cumulative luminosity function of our sample of low-activity comets was 0.33 ± 0.04, consistent with the slope we measured for the Jupiter-family cometary nuclei collected by Fernández et al. Fernández, J.A., Tancredi, G., Rickman, H., Licandro, J., 1999. Astron. Astrophys. 392, 327-340] of 0.38 ± 0.02. Our slopes of the cumulative size distribution α=1.50±0.08 agree well with the slopes measured by Whitman et al. Whitman, K., Morbidelli, A., Jedicke, R., 2006. Icarus 183, 101-114], Meech et al. Meech, K.J., Hainaut, O.R., Marsden, B.G., 2004. Icarus 170, 463-491], Lowry et al. Lowry, S.C., Fitzsimmons, A., Collander-Brown, S., 2003. Astron. Astrophys. 397, 329-343], and Weissman and Lowry Weissman, P.R., Lowry, S.C., 2003. Lunar Planet. Sci. 34. Abstract 34]. |
| Keywords: | Comets Photometry |
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