It could help us find more exoplanets far out in the universe
Astronomers may have stumbled upon four exoplanets when surveying distant red dwarf stars using only low-frequency radio waves. An international team of researchers led by the University of Leiden, the Netherlands, observed 19 M-type stars – ranging from 13 to 156 light-years away – using the Low Frequency Array (LOFAR), the world’s largest ground-based radio telescope that can detect frequencies less than 200MHz. M-type stars are known for being small, cool, and dim. Although they aren’t as visible as other stars like the Sun, they can be studied using radio waves. They commonly undergo intense magnetic activity that power stellar flares and bursts of radio light. These outbursts were identified with the help of deep learning, Benjamin Pope, a co-author of the study and an astrophysics lecturer at the University of Queensland, Australia, told El Reg. A convolutional neural network was trained to find flares ejected by such stars. But four of the 19 samples the network found left scientists puzzled; as they still emitted radio waves despite being magnetically inactive and dormant with no bright flares. “While plasma emission can generate the low-frequency emission from the most chromospherically active stars of our sample, the origin of the radio emission from the most quiescent sources is yet to be ascertained,” the team said in a paper published in Nature Astronomy on Monday (here’s the free arXiv pre-print).
