Searching for color variation on fast rotating asteroids with simultaneous V-J observations. Issue Volume 10:Issue S318(2015) (1st March 2016)

• Record Type: Journal Article
• Authors: Polishook, David; Moskovitz, Nicholas
• Editors: Chesley, S. R.; Morbidelli, A.; Jedicke, R.; Farnocchia, D.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 10:Issue S318(2015)
• Page Start: 193
• Page End: 200
• Publication Date: 2016-03-01
• Subjects: minor planets, -- asteroids, -- infrared: solar system; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921315006900
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: Boulders, rocks and regolith on fast rotating asteroids (<2.5 hours) are modeled to slide towards the equator due to a strong centrifugal force and a low cohesion force. As a result, regions of fresh subsurface material can be exposed. Therefore, we searched for color variation on small and fast rotating asteroids. We describe a novel technique in which the asteroid is simultaneously observed in the visible and near-IR wavelength range. In this technique, brightness changes due to atmospheric extinction effects can be calibrated across the visible and near-IR images. We use V - and J -band filters since the distinction in color between weathered and unweathered surfaces on ordinary chondrite-like bodies is most prominent at these wavelengths and can reach ~25%. To test our method, we observed 3 asteroids with Cerro Tololo's 1.3 m telescope. We find ~5% variation of the mean V-J color, but do not find any clearly repeating color signature through multiple rotations. This suggests that no landslides occurred within the timescale of space weathering, or that Landslides occurred but the exposed patches are too small for the measurements' uncertainty.