Noel Castro Segura

Astronomers have discovered a close pair of stars whose orbital dance is speeding up year after year. These are white dwarfs — superdense, cooled remnants of stars, roughly the size of Earth, where matter is compressed to a degenerate state.

Around certain close binary stars, where a white dwarf siphons matter from its companion, astronomers have seen a glowing arc. They took it for a shock wave — the place where a fast stellar wind slams into interstellar gas. But new observations show: there's more than one arc.

Long-period radio transients (LPTs) are a mysterious class discovered only recently. Their pulses last minutes or hours, and their nature was completely unknown. ASKAP J1745-5051, caught by the Australian telescope ASKAP, became the first to get a full explanation.