The Dark Energy Survey

The Dark Energy Survey (DES) is a 5000 square degree survey of the southern sky that is taking place from August 2013 to February 2018.

Over the 525 nights of the survey, the DES will observe in five filters (SDSS-like griz, plus Y-band), and will have significant overlap regions with other wide-area surveys.

grizy filters

The grizy filters which are used cover a range of wavelengths from green light into infrared.

The filter response curves for each of the g, r, i, z, y filters used in the Dark Energy Survey

Shown in the figure below is the footprint of the Dark Energy Survey.

Wide-Area Survey Boundaries

DES Footprint


The four Key Science programs of the DES include measurements of SNe Ia, Baryon Acoustic Oscillations, Galaxy Clusters, and Weak Gravitational Lensing. Together these four probes will measure the time-dependent and time-independent components of the Dark Energy Equation of State with unprecedented precision.


The DES data have many uses beyond these primary science goals, however. For example, once a region of the sky has been observed for the DES, those observations will be useful whenever a transient (e.g. a gamma-ray burst) is observed in the region.

The DESAlert system is modeled upon the SkyAlert system, though it focuses exclusively on data produced by the DES. When a VOEvent notice is disseminated by the Swift satellite, the DESAlert system parses the notices for temporal and positional information, and then searches the DES database of archival data to find all observations of that region.

DESAlert then provides finder images of the region, as well as information about all nearby stars and galaxies as a service to those who plan follow-up observations of the GRB. The finder charts show the immediate environment of the GRB, while the catalog of stars provide nearby standards for the purpose of immediate relative photometry. Meanwhile, the galaxy catalog provides critical information on potential hosts (especially magnitude, morphology, and redshift) for the given GRB.

Once the system hs detected one or more GRBs, an interactive map will be available below to shows the locations of the GRBs within the DES footprint.  Instructions for subscribing to the VOEvent stream produced by DESAlert will be provided as well.

For further details, see the DESAlert paper currently submitted for publication.