The system works like a cosmic lighthouse. At its heart is a white dwarf — a dead star the size of Earth, but two and a half times hotter than the Sun. Nearby orbits a tiny companion — a brown dwarf, 20 times lighter than the Sun, that failed to ignite. It’s so close that its matter spills onto the white dwarf, forming a scorching accretion disk. The gas, spiraling inward, heats up from friction and emits a narrow radio beam. The pair rotates once every 1.37 hours, sweeping the beam across space, and we catch brief flares when it points at Earth.

That’s why the source hid for so long: its beam is too narrow. Telescopes helped capture it by analyzing light through spectral analysis and brightness measurements. Computer modeling showed that the system has passed the stage of closest approach and is fading: this is a late stage of binary star evolution. The light was distorted by the interstellar medium and cosmic dust, but corrections were made. An unexpected twist: the companion turned out to have the mass of a giant planet, yet its proximity to the white dwarf means it is evaporating, feeding the lighthouse. The discovery builds on decades of work: Subrahmanyan Chandrasekhar on white dwarfs, Karl Jansky, who pioneered radio astronomy, and Jocelyn Bell Burnell, who discovered pulsars with a similar rotating beam.