The world’s largest radio telescope observed Barnard’s Star in search of signals from alien civilizations
Barnard’s Star is a small red dwarf star located just six light years from Earth. Despite its proximity, it was discovered only in 1916, when E.E. Barnard discovered a particularly high intrinsic velocity of this star. It was seen on Harvard Observatory photographic plates taken in the late 1800s, but as a small and faint star, it received little attention. But since then, Barnard’s star has become one of the most studied red dwarfs.
Barnard’s Star was one of the first stars to have planets discovered. Already in the 1970s, it was announced that there were giant planets in the orbit of this star, but further observations refuted these results. Then in 2018, astronomers measured the star’s radial motion, indicating the presence of an exoplanet around 3 Earths in mass around the star. However, subsequent observations refuted this discovery, indicating that the radial fluctuations seen earlier were caused by starbursts. Recent studies have confirmed that Barnard’s star does not have nearby planets that could be larger than 70% of the size of Earth and potentially habitable.
The FAST radio telescope scanned Barnard’s Star in search of extraterrestrial signals
This makes Barnard’s star somewhat unusual since most red dwarfs have planets. For example, the star Kepler-42, similar in size and age to Barnard’s star, has at least three exoplanets. So while Barnard’s Star isn’t a strong candidate for extraterrestrial life, a recent study has made detailed observations of the star looking for signs of an alien signal.
The study used the 500-meter spherical radio telescope FAST. The Chinese telescope has an antenna design similar to the Arecibo Observatory but is significantly larger. FAST operates in the frequency range from 70 MHz to 3 GHz, making it a good tool for searching for alien life.
During the study of Barnard’s Star, the astronomer looked for emissions that might be noticeable if an alien civilization were sending radio messages in our direction. The team focused its search on signals coming from Barnard’s hypothetical super-Earth b and took into account the Doppler effect caused by the relative motion between it and Earth.
As might be expected, the study found no evidence of an alien signal. However, this study was mainly a test of the capabilities of the FAST telescope. Future studies, especially those aimed at nearby stars with confirmed planets in the habitable zone, will have a higher chance of detecting signals.
