Red supergiants are massive stars near the end of their lives, and are direct progenitors of core-collapse supernovae 7,8. They evolve from O- and B-type stars (hot, luminous sources of ionizing ...

Speed matters. When an X-ray photon excites an atom or ion, making a core electron jump onto a higher energy level, a short-lived window of opportunity opens. For just a few femtoseconds, before an ...

Researchers at Kyoto University have determined that the iron Kα line in stellar flares is produced by photoionization from hot flare plasma. Simultaneous ultraviolet and X‑ray observations of a ...

The idea that light can behave as both a particle and a wave is one of the strange central concepts in quantum mechanics known as wave-particle duality. Towards the end of the 19 th century and the ...