The DESI Transients Survey: Legacy Classifications and Methodology
Abstract
We present the first systematic spectroscopic observations of extragalactic transients from the Dark Energy Spectroscopic Instrument (DESI), as part of the DESI Transients Survey program. With 5,000 fibers and an deg field of view, we exploit DESI as a machine for the discovery and classification of transients. We present transient classifications from archival DESI data in Data Releases 1 and 2, relying on a combination of a secondary target program and serendipitous observations. We also present observations from the first 6 months of the DESI spare fiber program dedicated to transients. The program is run in coordination with a dedicated DECam time-domain survey, serving as a pathfinder for what we will be able to achieve in conjunction with the Rubin Observatory Legacy Survey of Space and Time (LSST). We classify over 250 transients, of which the majority were previously unclassified. The sample comprises thermonuclear and core-collapse supernovae and tidal disruption events (TDEs), including a TDE observed before its discovery in imaging. We demonstrate DESI's ability to classify a population of faint transients down to mag during main survey operations, with negligible impacts on DESI's main observations.
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Cite
@article{arxiv.2601.12611,
title = {The DESI Transients Survey: Legacy Classifications and Methodology},
author = {Xander J. Hall and Antonella Palmese and Segev BenZvi and John Banovetz and Brendan O'Connor and Lei Hu and Erica Hammerstein and Ariel Amsellem and Jessica Nicole Aguilar and Steven Ahlen and Steven Bailey and Davide Bianchi and David Brooks and Todd Claybaugh and Andrei Cuceu and Kyle Dawson and Axel de la Macorra and John Della Costa and Arjun Dey and Peter Doel and Simone Ferraro and Andreu Font-Ribera and Jaime E. Forero-Romero and Enrique Gaztanaga and Satya Gontcho A Gontcho and Alma Xochitl Gonzalez-Morales and Or Graur and Gaston Gutierrez and Mustapha Ishak and Jorge Jimenez and Dick Joyce and Stephanie Juneau and Anthony Kremin and Ofer Lahav and Claire Lamman and Martin Landriau and Laurent Le Guillou and Alexie Leauthaud and Michael Levi and Marc Manera and Aaron Meisner and Ramon Miquel and John Moustakas and Adam Myers and Seshadri Nadathur and Will Percival and Claire Poppett and Ignasi Perez-Rafols and Francisco Prada and Graziano Rossi and Eusebio Sanchez and Edward Schlafly and David Schlegel and Michael Schubnell and David Sprayberry and Gregory Tarle and Benjamin Alan Weaver and Rongpu Zhou and Hu Zou},
journal= {arXiv preprint arXiv:2601.12611},
year = {2026}
}