The Young Supernova Experiment has made available three years of data from the largest data release of relatively nearby supernovae (colossal explosions of stars) (YSE). Celestial phenomena that change over time, such as exploding stars, mysterious objects that suddenly brighten, and variable stars, have opened up a new frontier in astronomical research, with telescopes capable of rapidly surveying the sky and revealing thousands of these objects.
The Young Supernova Experiment has made public the largest data release of relatively nearby supernovae (colossal explosions of stars), containing three years of data from the University of Hawaii Institute for Astronomy’s (IfA) Pan-STARRS telescope atop Haleakal on Maui (YSE). The project, which began in 2019, surveyed more than 1,500 square degrees of sky every three days, discovering thousands of new cosmic explosions and other astrophysical transients, many of which exploded just days or hours later.
The newly released data includes observations in multiple colors for nearly 2,000 supernovae and other luminous variable objects. It is also the first to use multi-color imaging extensively to classify supernovae and estimate their distances.
Pan-STARRS produces a steady stream of transient discoveries by observing large areas of the sky with two telescopes every clear night. Pan-STARRS operates one of the best-calibrated systems in astronomy, with a detailed reference image of the static sky visible from Haleakal.Mark Huber
Large imaging surveys (systematic studies of large areas of the sky over time) and different parts of the electromagnetic spectrum are used by astronomers for a variety of scientific purposes. Some are used to study distant galaxies and how they evolve over cosmic time, while others are used to study specific regions of the sky, such as the Andromeda Galaxy.
“Pan-STARRS produces a steady stream of transient discoveries by observing large areas of the sky with two telescopes every clear night,” said Mark Huber, a senior researcher at IfA. “Pan-STARRS operates one of the best-calibrated systems in astronomy, with a detailed reference image of the static sky visible from Haleakal. This allows for the rapid detection and follow-up of supernovae and other transient events, making it ideal for programs like YSE to collect the sample needed for analysis and this significant data release.”
YSE is intended to detect energetic astrophysical “transient” sources like supernovae, tidal disruption events, and kilonovae (extremely energetic explosions). These transients evolve quickly, reaching their peak brightness and then dissipating after a few days or months.
The Pan-STARRS Image Processing Pipeline transfers Pan-STARRS images to UH’s Information Technology Center for initial processing and scientific calibration. Higher-level processing, detailed analysis, and storage were then carried out on computing systems at the National Center for Supercomputing Applications’ (NCSA) Center for Astrophysical Surveys (CAPS), the University of California, Santa Cruz (UCSC), and the Niels Bohr Institute’s (DARK) Dark Cosmology Centre (DARK).
The survey and the data-analysis tools are important precursors to the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time, a new 8.4-meter telescope being built in Chile. Rubin Observatory will survey the entire sky every three nights, discovering so many variables and exploding objects that detailed follow-up observations will be impossible. The ability to classify these objects solely based on survey data will be critical in determining which ones to target with other telescopes.
The cosmological analysis for the data sample is being led by Gautham Narayan, deputy director of CAPS, and former CAPS graduate fellow Patrick Aleo is the lead author of the paper, “The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae.”
“Much of the time-domain universe remains unexplored. While we continue to use these sources to try to understand the expansion history of our universe, we still do not know the progenitor systems of many of the most common classes of transients, such as type Ia supernovae” said Narayan. “One electromagnetic counterpart to a binary neutron star merger has also been observed. Many types of transients are theoretically predicted but have never been observed.”
Pan-STARRS director Ken Chambers added: “This collaboration with the Young Supernova Experiment makes excellent use of Pan-STARRS’ ability to survey the sky on a regular basis for transient phenomena and moving objects. We have provided an unprecedented sample of young supernovae discovered prior to their peak luminosity, which will be a valuable resource for supernova researchers and cosmologists for many years to come. Pan-STARRS will continue to be an important resource in the Northern Hemisphere, complementing the Rubin Observatory in the Southern Hemisphere.”