Shaky signals from an aurora on a planet far from the solar system: research highlights
Astronomy and astrophysics
April 16, 2021
A huge radio observatory on earth detects signals similar to those of the aurora on Jupiter.
Radio astronomers have discovered perhaps the strongest evidence yet that a planet outside the solar system has aurors similar to Earth’s northern lights.
Joseph Callingham of the Leiden Observatory in the Netherlands and his colleagues searched data from a sky survey with the Low-Frequency Array (LOFAR), a gigantic array of antennas in Northern Europe. To their surprise, the team found multiple sources of circularly polarized radiation, meaning that the electrical fields of the radio signal spiraled like a corkscrew as it moved through space. It is not known that astrophysical objects other than planets are circularly polarized light sources with a steady twist, as is the case with the observed LOFAR-type.
The most intriguing signal came from CR Draconis, a pair of tightly orbiting red dwarf stars 20 parsecs (65 light years) from Earth. LOFAR had observed the system for 21 periods of about 8 hours each, resulting in radiation in a pattern reminiscent of auroras observed on Jupiter. The astronomers suggest that the effect is created in the atmosphere of a Jupiter-like planet or by the rapid rotation of one of the stars.