Electronic Telegram No. 279, (3309) Brorfelde, 7 November 2005[5] Photometric observations obtained from 25 October to 3 November 2005, revealed that 3309 Brorfelde is a binary system with an orbital period of 18.48±0.01 hours. The primary rotates with a period of 2.5041±0.0002 hours, and its light-curve has a brightness variation of 0.13 magnitude, indicating a nearly spheroidal shape. Mutual eclipse/occultation events with an amplitude of 0.07-0.15 magnitude suggest a ratio of 0.26±0.02 for its secondary-to-primary mean-diameter. Assuming G = 0.15, the calibrated data gives an absolute magnitude of 13.4±0.2. B. D. Warner, Palmer Divide Observatory, Colorado Springs; P. Pravec and P. Kusnirak, Ondrejov Observatory; W. Cooney, J. Gross, and D. Terrell, Sonoita Research Observatory, Sonoita, AZ; and S. Nudds, Elginfield Observatory, University of Western OntarioCentral Bureau for Astronomical Telegrams No.279