Nature: Two years ago a rare red nova, dubbed V1309 Scorpii, appeared in a part of the sky being monitored by the Optical Gravitational Lensing Experiment (OGLE) in Chile. Unlike the more common blue novae, which correspond to thermonuclear explosions on white dwarfs, red novae are more mysterious. Now, having examined data taken before V1309 Scorpii’s flare-up, the OGLE team has determined its cause: the merger of two stars that had been orbiting each other so closely that their atmospheres overlap. Such orbits inevitably shrink as the overlapping atmospheres drain orbital energy from the binary system. Nature‘s Ken Croswell describes the serendipitous discovery.
The finding that the Saturnian moon may host layers of icy slush instead of a global ocean could change how planetary scientists think about other icy moons as well.
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.
January 29, 2026 12:52 PM
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