W. J. Merline, Southwest Research Institute (SwRI); P. M. Tamblyn, Binary Astronomy, Dillon, CO, U.S.A., and SwRI; J. D. Drummond, Starfire Optical Range, Air Force Research Laboratory; J. C. Christou, Gemini Observatory; A. R. Conrad, W. M. Keck Observatory; B. Carry, Observatoire de Paris; C. R. Chapman, SwRI; C. Dumas, European Southern Observatory (Chile); D. D. Durda, SwRI; W. M. Owen, Jet Propulsion Laboratory; and B. L. Enke, SwRI, report the discovery on Nov. 24.4 UT of a satellite of minor planet (317) Roxane from K_p-band imaging using the 8-m Gemini-North telescope (+ Altair/NIRI adaptive-optics system). On Nov. 24.39992, the satellite was at separation 0".27 (projected separation 245 km) and position angle 76 deg. The satellite was imaged in K_p-, H-, and J-bands and was tracked for more than 26 hours. The brightness difference in the K_p band is about 2.7 mag, giving an estimated diameter (primary diameter assumed of 19 km) of the satellite of 5 km. This binary has characteristics that are very similar to the other wide binaries previously reported by the authors (see IAUCs 7827, 8075, 8232, 8293, 8297), all being consistent with the EEB formation mechanism of Durda et al. (2004, Icarus 170, 243). Among binaries that can be resolved by imaging, this appears to be the first of type E. Given the recent detection of dual lightcurve periods in (1509) Esclangona (CBET 2020), it is possible that separate spin periods could be extracted from lightcurve data of (317).
International Astronomical Union Circular
- Pub Date:
- December 2009