AAVSO: American Association of Variable Star Observers
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What's Next in Asteroid Photometry? (Abstract)

Volume 37 number 2 (2009)

Gary A. Vander Haagen

Abstract

(Abstract only) Our knowledge of an asteroid starts with determination of its position over time using astrometry, calculation of orbital parameters, and collection of time-series photometry data to reveal its light curve, rotational period, and amplitude. Selectively, radar studies are performed by Arecibo and Goldstone to obtain orbital, size, shape, and surface data. Further insight into asteroid populations, general taxonomic class, albedos, estimated diameters, and shape require knowledge of their absolute magnitude (H) and phase slope parameter (G) values. The H-G values are determined through reduced photometric data as the asteroid passes through its opposition or 00 phase angle. Collection of these data is ideally suited to smaller observatories since the time required is considerable and therefore costly for larger facilities. The H-G parameters were determined for 901 Brunsia and 946 Poesia, thereby yielding new insight into their absolute magnitudes, albedos, diameter, and general taxonomic classification.