J. Pollock, Appalachian State University; P. Pravec, P. Kusnirak, and K. Hornoch, Ondrejov Observatory; V. Chiorny, Kharkiv Observatory; S. Gajdos, Modra Observatory; and D. E. Reichart, K. M. Ivarsen, J. B. Haislip, and A. LaCluyze, Physics and Astronomy Department, University of North Carolina at Chapel Hill, report that photometric observations obtained during 2011 Mar. 7 to Apr. 9 reveal that minor planet (2815) is a binary system with an orbital period of 17.915 +/- 0.002 hr. The primary shows a period of 2.73325 +/- 0.00007 hr and it has a lightcurve amplitude of 0.07 mag, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.12- and 0.07-mag deep indicate a secondary-to-primary mean-diameter ratio of 0.25 +/- 0.02. The mean absolute R magnitude of the system is H_R = 12.53 +/- 0.02 and the phase relation slope parameter G = 0.27 +/- 0.04. F. Marchis, J. E. Enriquez, and M. Allain, Carl Sagan Center at the SETI Institute; and J. P. Emery, University of Tennessee at Knoxville, report on integrated spectroscopic observations of the binary system (2815) recorded from 2011 Apr. 1.4356 to 1.4832 UT with Infrared Telescope Facility's SPEX instrument. A solar analogue (SAO 119577) was observed before and after the target to compute a final reflectance spectrum from 0.67 to 2.55 microns. Following the Bus-DeMeo taxonomy, the near-infrared spectrum is typical of Sq-type minor planets, characterized by a wide 1-micron absorption band with evidence of an absorption feature near 1.3 microns.
Central Bureau Electronic Telegrams
- Pub Date:
- April 2011