Panchromatic Observations of SN2011dh Point to a Compact Progenitor Star

We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN2011dh using data from the Swift and Chandra satellites, placing it among the best studied X-ray supernovae to date. We further present millimeter and radio data obtained with the SMA, CARMA, and EVLA during Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA National Radio Astronomy Observatory, Socorro, NM 87801, USA School of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540, USA Bachall Fellow, Einstein Fellow NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA Department of Physics, Tokyo Institute of Technology, 2-12-1 Ohokayama, Meguro, Tokyo 152-8551, Japan Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450, USA University of Virginia, Astronomy Department, Charlottesville, VA 22904, USA CASA, Dept. of Astrophysical and Planetary Sciences, University of Colorado 389-UCB, Boulder, CO 80309, USA Raymond and Beverly Sackler School of Physics & Astronomy, Tel Aviv University, Tel Aviv 69978, Israel Department of Astronomy, The Oskar Klein Centre, Stockholm University, 106 91 Stockholm, Sweden Max-Planck-Institute für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany Dept. of Physics and Astronomy, York University, Toronto, M3J 1P3, Ontario, Canada Hartebeesthoek Radio Observatory, P.O. Box 443, Krugersdorp, 1740, South Africa Institute of Astronomy, RAS, Pyatnitskaya 48, Moscow 11917, Russia Physics Department, The University of Alabama in Huntsville, Huntsville, AL 35809, USA Universities Space Research Association, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805, USA Max-Planck-Institut fr extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany Ioffe Physical-Technical Institute of the Russian Academy of Sciences, St. Petersburg 194021, Russia Emeritus, NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771, USA