GeminiFocus October 2017 | Page 13

Peter Michaud Science Highlights Data from the Gemini Multi-Object Spectrograph on Gemini South verifies one of the most distant superluminous supernovae ever studied. Astronomers at Gemini South confirm a new class of variable stars, called Blue Large-Amplitude Pulsators. Joint Gemini and Canada-France-Hawai‘i GRACES observations at Maunakea help in the study of a white dwarf star hurtling through our Galactic neighborhood 50 million years after a supernova blast. And Gemini near-infrared data from Gemini North unmask the mysterious Infrared Quintuplet at the Galactic center. A Super-distant, Superluminous Supernova Observations conducted with the Gemini Multi-Object Spectrograph on the 8-meter Gemini South telescope have confirmed that a brilliant explosion more than three times as bright as our Milky Way Galaxy is one of the most distant supernovae ever studied. The event, known as DES15E2mlf, occurred about 3.5 billion years after the Big Bang, at a period known as “cosmic high noon,” when the rate of star formation in the Universe had reached its peak. DES15E2mlf was initially detected in November 2015 by the Dark Energy Survey (DES). Fol- low-up observations at Gemini South not only confirmed the object’s distance of 10 billion light years, but also revealed its unusual nature. Previous observations of superluminous supernovae show that they typically reside in low-mass or dwarf galaxies, which tend to be less enriched in metals than more massive galaxies. However, University of California Santa Cruz astronomers Yen-Chen Pan and Ryan Foley, who led the Gemini investigation as part of an international team of DES collaborators, found that the host galaxy of DES15E2mlf, is a fairly massive normal-looking galaxy, which goes counter to current thinking. October 2017 GeminiFocus 11