The 2010 Eruption of U Scorpii (Abstract)

Volume 39 number 1 (2011)

Ashley Pagnotta

3102 Brook Grove Drive, Kingwood, TX 77345; pagnotta@phys.lsu.edu

Abstract

(Abstract only) We report on the 2010 eruption of the recurrent nova U Scorpii. This outburst was predicted in 2005 and discovered independently by AAVSO observers Barbara G. Harris and Shawn Dvorak on 28 January 2010 as a result of a monitoring program coordinated by our group at LSU in conjunction with the AAVSO. The eruption lasted approximately 64 days, over the course of which more than 35,000 pre-arranged and serendipitous observations were made in all wavelengths from radio to x-ray. We present multi-wavelength light curves (UBVRIJHKby+UV+x-ray) of the entire eruption which show the overall speed of the event, the expected first plateau, the unexpected second plateau, and the return to quiescence. As anticipated, the onset of the optical plateau coincided with the turn-on of the supersoft x-ray emission and the re-emergence of the eclipses. Our comprehensive coverage shows fine-scale phenomena as well, such as flares of up to 0.5 magnitude in amplitude during the initial fast decline which are as yet unexplained and late aperiodic dips (distinct from the well-known eclipses) that are likely caused by accretion disk geometry.