Researchers from the University of Warwick and the University of Colorado Boulder have discovered four previously hidden white dwarfs in binary star systems located no farther than 65 light-years from Earth. The results of the study were published in the Monthly Notices of the Royal Astronomical Society (MNRAS). Notably, one of the discovered objects turned out to be the ninth closest white dwarf to the Sun, despite astronomers studying this region of space for many years. In all four systems, the white dwarfs orbit red dwarfs. The brighter red stars completely obscured their compact companions, so the systems were long considered single. “White dwarfs located nearby are usually quite easy to detect. But these four objects were hidden by the light of the red dwarfs. This reminds us that even in our closest cosmic surroundings, surprises may remain,” noted the lead author of the study, Dr. Maire O'Brien. The suspicion of hidden objects arose due to a slight periodic “wobble” of the red dwarfs. Such oscillations typically indicate the presence of a massive companion. To confirm the discovery, scientists used the ultraviolet spectrograph of the Hubble Space Telescope. The observations were challenging, as flares from the red dwarfs could mimic signals from the white dwarfs. To process the data, researchers had to develop special calibration methods. The system G 203-47, located just 25 light-years from Earth, garnered the most interest. Despite its proximity, the white dwarf was only detected 27 years after astronomers first noticed the unusual motion of its companion star. The study revealed another feature of this system. The red dwarf rotates on its axis significantly slower than it orbits the white dwarf, which contradicts common models of the evolution of such binary systems. “This suggests that such systems may have gone through entirely different stages of development. Some have experienced prolonged and tumultuous interactions, while others have undergone much calmer evolution,” explained co-author Dr. David Wilson. The discovery allowed scientists to update the catalog of white dwarfs within 20 parsecs (about 65 light-years) of Earth. Interestingly, the number of detected objects almost completely matched the predictions of theoretical models. According to Professor Pierre-Emmanuel Tremblay, only about 30% of the nearest red dwarfs have been thoroughly surveyed so far. This means that there may be another nine or ten similar binary systems hiding near the Sun that astronomers have yet to discover. The new study shows that even the closest area of space to Earth continues to hold discoveries that could change scientists' understanding of stellar evolution. Previously, the Euclid telescope [discovered](https://bb.lv/statja/tehno/2026/07/07/teleskop-evklid-obnaruzil-drevneisie-kvazary-ix-svet-sel-k-zemle-okolo-13-milliardov-let) the oldest quasars: their light has been traveling to Earth for about 13 billion years.