A team of astronomers led by the Flatiron Institute’s Kishalay De discovered that a star in the Andromeda Galaxy disappeared without going supernova, and instead collapsed directly into a black hole. The team’s analysis of the star, reported in Science, reveals what happened and helps explain why some massive stars turn into black holes while others don’t.

Researchers at Oxford University and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) are proposing a new way to observe tightly bound supermassive black hole binaries. Formed naturally when galaxies merge, only widely separated systems have confidently been observed to date. In a paper published today in Physical Review Letters, the researchers suggest hunting down the hidden systems by searching for repeating flashes of light from individual stars lying behind the black holes as they are temporarily magnified by gravitational lensing as the binary orbits. 

Researchers at the Helmholtz-Zentrum Hereon recently introduced a fully recyclable ink for 3D printing that is made from the abundant industrial byproduct lignin. This ink, presented in a paper published in the Journal ACS Sustainable Chemistry & Engineering, could substitute fossil-based materials that are currently used to print various consumer goods, product prototypes and technological components. Its unique properties enable the printing of items with excellent resolution, shape stability at temperatures up to 200 °C, and their recycling via a rehydration process.