Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 1, 2011 | Submitted + Published
Journal Article Open

SN 2011dh: Discovery of a Type IIb Supernova from a Compact Progenitor in the Nearby Galaxy M51


On 2011 May 31 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras and also detected it with the Palomar Transient Factory survey, rapidly confirming it to be a Type II SN. Here, we present multi-color ultraviolet through infrared photometry which is used to calculate the bolometric luminosity and a series of spectra. Our early-time observations indicate that SN 2011dh resulted from the explosion of a relatively compact progenitor star. Rapid shock-breakout cooling leads to relatively low temperatures in early-time spectra, compared to explosions of red supergiant stars, as well as a rapid early light curve decline. Optical spectra of SN 2011dh are dominated by H lines out to day 10 after explosion, after which He I lines develop. This SN is likely a member of the cIIb (compact IIb) class, with progenitor radius larger than that of SN 2008ax and smaller than the eIIb (extended IIb) SN 1993J progenitor. Our data imply that the object identified in pre-explosion Hubble Space Telescope images at the SN location is possibly a companion to the progenitor or a blended source, and not the progenitor star itself, as its radius (~10^(13) cm) would be highly inconsistent with constraints from our post-explosion spectra.

Additional Information

© 2011 American Astronomical Society. Received 2011 June 19; accepted 2011 October 4; published 2011 November 4. The Weizmann Institute PTF partnership is supported by the Israeli Science Foundation via grants to A.G. Collaborative work between A.G. and S.R.K. is supported by the US-Israel Binational Science Foundation. A.G. further acknowledges support from the EU FP7 Marie Curie program via an IRG fellowship and a Minerva grant. P.E.N. is supported by the US Department of Energy Scientific Discovery through Advanced Computing program under contract DE-FG02-06ER06-04. M.S. acknowledges support from the Royal Society; M.S. and A.G. are also grateful for a Weizmann-UK Making Connections grant. A.V.F.'s supernova group at U.C. Berkeley acknowledges generous support from Gary and Cynthia Bengier, the Richard and Rhoda Goldman Fund, US National Science Foundation grant AST-0908886, and the TABASGO Foundation. J.S.B. acknowledges support of an NSF-CDI grant 0941742 and NSF/AAG grant NSF/AST-100991. P.M., E.P., and E.S.W. acknowledge financial support from INAF through PRIN INAF 2009. Instrumentation at Wise Observatory was funded in part by the Israel Space Agency (ISA), the Max Planck Institute for Astronomy (MPA) in Heidelberg, Germany, the German Israeli Science Foundation for Research and Development, and the Israel Science Foundation. The WHT is operated by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The Byrne Observatory at Sedgwick (BOS) is operated by the Las Cumbres Observatory Global Telescope Network. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA; it was made possible by the generous financial support of the W. M. Keck Foundation. PAIRITEL is operated by the Smithsonian Astrophysical Observatory (SAO) and supported by the Harvard University Milton Fund, the University of Virginia, SAO, UC Berkeley, and NASA via Swift Guest Investigator programs NNX09AQ66Q and NNX10A128G. We are grateful to the dedicated staffs at all of the observatories where we obtained data. The National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, provided staff, computational resources, and data storage for this project.

Attached Files

Published - Arcavi2011p16472Astrophys_J_Lett.pdf

Submitted - 1106.3551.pdf


Files (1.4 MB)
Name Size Download all
918.6 kB Preview Download
455.8 kB Preview Download

Additional details

August 19, 2023
October 24, 2023