DES-SN Transients

The Dark Energy Survey Supernova Program (DES-SN) publishes its brighter (r ≲ 20) transient candidates here, and encourages other observers to follow them up. As a courtesy, we also request that observers who do follow-up transients listed here inform DES-SN by sending an email to brightdestransients@gmail.com.

Coordinates, photometry, and subtraction postage stamps are available to help users decide what candidates interest them most. Finder charts with offset stars are provided to facilitate follow-up.

DES-SN Fields and Exposure Times

DES-SN is a search for astrophysical transients in which ten 3-deg2 fields are repeatedly observed by the Dark Energy Camera (DECam) in g,r,i,z passbands with a cadence of about one week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernovae with the goal of measuring Dark Energy parameters.

Field name letters are E for Elais S1, S for SDSS Stripe 82, C for CDFS, and X for XMM-LSS. Coordinates at the center of each 3-deg2 field are listed below.

FieldR.A.Dec.Type
C103:37:05.83-27:06:41.8shallow
C203:37:05.83-29:05:18.2shallow
C303:30:35.62-28:06:00.0deep
E100:31:29.86-43:00:34.6shallow
E200:38:00.00-43:59:52.8shallow
S102:51:16.80+00:00:00.0shallow
S202:44:46.66-00:59:18.2shallow
X102:17:54.17-04:55:46.2shallow
X202:22:39.48-06:24:43.6shallow
X302:25:48.00-04:36:00.0deep

Exposure sequences (number of exposures times exposure time in seconds) for shallow and deep fields are listed below.

Typegriz
Shallow1 x 175s1 x 150s1 x 200s2 x 200s
Deep3 x 200s3 x 400s5 x 360s11 x 330s

The above field definitions and exposure times are up-to-date as of 2015-09-30. Refer to Kessler et al. (2015) for more details.

DES Transient Names

Transients identified by DES-SN are given names according to a familiar scheme:

The above example corresponds to a transient in the X2 field, the 731st transient identified by DES-SN in 2015. The alphabetic suffix is re-started at the beginning of each observing season, and a suffix is not used again until the following year.

The search box accepts partial candidate names. If multiple candidates match a partial name, up to 30 matches are listed for the user to narrow down within.

DES and DECam

DES is designed to probe the origin of the accelerating Universe and help uncover the nature of Dark Energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 300 scientists from 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, and Switzerland are working on DES.

DES has built and deployed an extremely sensitive 570-Megapixel digital camera, called DECam, on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes. Nightly, up to 170 GB of DES-SN survey exposures are transferred from CTIO to the National Center for Supercomputing Applications (NCSA) where they are processed and differenced against template images from previous years. A machine learning classifier separates potentially real astrophysical transients from various detector and mis-subtraction artifacts. The entire process is complete in a matter of hours.

Crediting DES-SN in Publications

Peer-reviewed publications incorporating observations of transients advertised here should acknowledge DES and CTIO. Please include acknowledgement text from here and cite the following relevant articles:

Supernova Simulations and Strategies for the Dark Energy Survey
Bernstein, J. P., et al., 2012, The Astrophysical Journal, 753, 152
The Dark Energy Camera
Flaugher, B., et al., 2015, The Astronomical Journal, accepted
Automated Transient Identification in the Dark Energy Survey
Goldstein, D. A., et al., 2015, The Astronomical Journal, 150, 82
The Difference Imaging Pipeline for the Transient Search in the Dark Energy Survey
Kessler, R., et al., 2015, The Astronomical Journal, accepted

Funding Acknowledgment

Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey.

The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenössische Technische Hochschule (ETH) Zürich, Fermi National Accelerator Laboratory, the University of Illinois at Urbana-Champaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Física d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universität München and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, the Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, and Texas A&M University.

The DES data management system is supported by the National Science Foundation under Grant Number AST-1138766. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2012-39559, ESP2013-48274, FPA2013-47986, and Centro de Excelencia Severo Ochoa SEV-2012-0234. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. This research uses resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.


We encourage observers to follow-up as many bright DES transients as they wish. Peer-reviewed publications resulting from observations of transients advertised here should acknowledge DES and CTIO. Contact to report issues.