Unlocking the Mysteries of FU Orionis: Hubble's Latest Discovery
Credits: NASA-JPL, Caltech In the constellation Orion, astronomers saw in 1936 something quite extraordinary: the young star FU Orionis (FU Ori) brightened by 100 times within a few months. Unlike an exploding star, FU Ori has been gradually fading since then. Now, some 90 years later, the NASA Hubble Space Telescope has made new discoveries about this interesting star with its ultraviolet capabilities. Astronomers aimed to study the interaction between FU Ori’s surface and its accretion disk—the massive structure of gas spiraling onto the star. Using Hubble's Cosmic Origins Spectrograph (COS) and Space Telescope Imaging Spectrograph (STIS), they captured unprecedented ultraviolet spectra of FU Ori. Data revealed a surprise-the region where the accretion disk meets the star is much hotter than expected, reaching temperatures of 16,000 kelvins - nearly three times hotter than our Sun's surface and double what previous models predicted. "We were hoping to validate the disk...