Free Astronomy Magazine May-June 2025

36 MAY-JUNE 2025 ASTRO PUBLISHING revealed highly unusual chemical emissions as well as one of the hottest temperatures ever reported for a nova, both indicative of an ex- tremely violent eruption. Nova explosions occur in binary star systems in which a white dwarf — the dense remnant of a dead star — continually siphons stellar material from a nearby companion star. As the outer atmosphere of the com- panion gathers onto the surface of the white dwarf it reaches temper- atures hot enough to spark an eruption. Almost all novae discov- ered to-date have been observed to erupt only once. But a few have been observed to erupt more than once, and are classified as recurrent novae. The span between eruptions U sing the Gemini South tele- scope, one half of the Inter- national Gemini Observatory, partly funded by the U.S. National Science Foundation and operated by NSF NOIRLab, and the Magellan Baade Telescope, astronomers have for the first time observed a recur- ring nova outside of the Milky Way in near-infrared light. The data by NOIRLab Josie Fenske Ultra-hot nova with surprising chemical signature