Comparing Phoebe's 2005 opposition surge in four visible light filters

作者：Miller C^*; Verbiscer A J; Chanover N J; Holtzman J A; Helfenstein P

来源：Icarus, 2011, 212(2): 819-834.

DOI：10.1016/j.icarus.2010.12.024

• Regoliths
• Saturn, Satellites
• Satellites, Surfaces
• Kuiper Belt

We observed Phoebe for 13 nights over a period of 55 days before, during, and after the 2005 Saturn opposition with the New Mexico State University (NMSU) 1-m telescope at Apache Point Observatory (APO) in Sunspot, NM and characterized the width and magnitude of Phoebe's opposition surge in BVRI filters. Our observations cover a phase angle range of 4.87 degrees to 0.0509 degrees. We use a Hapke reflectance model incorporating shadow hiding and coherent backscatter to investigate the wavelength dependence of Phoebe's opposition surge. We find a significant opposition surge magnitude of 55-58% between phase angles of 5 degrees and 0 degrees. We find the strongest opposition surge for phase angles less than 2 degrees in the I-band. The coherent backscatter angular width is on the order of 0.50 degrees. We find Phoebe's albedo to be spectrally flat within our error limits, with a B-band albedo of 0.0855 +/- 0.0031, a V-band albedo of 0.0856 +/- 0.0023, an R-band albedo of 0.0843 +/- 0.0020, and an I-band albedo of 0.0839 +/- 0.0023. We compare Phoebe's albedo, color, and opposition surge magnitudes and slopes with those of other outer solar system bodies and find similarities to Centaurs, Nereid, Puck, and Comets 19P/Borrelly, 9P/Tempel 1, and 81P/Wild 2. We find that this comparison supports the idea that Phoebe originated in the Kuiper Belt. We also discuss the caveats of using results from a Hapke reflectance model to derive specific surface particle properties.

• 出版日期2011-4