Barnard’s Star is a small red dwarf located just six light-years from Earth. Despite its proximity, only in 1916 did EE Barnard discover that this star was moving at a particularly high speed. It was seen on the Harvard Observatory’s photographic plates taken in the late 1800s, but was overlooked because it was a small and faint star. But since then, Barnard’s star has become one of the most studied red dwarfs.

Barnard’s star was one of the first stars in which planets were discovered. Already in the 1970s, the existence of giant planets orbiting this star was announced, but subsequent observations refuted these conclusions. Later in 2018, astronomers measured the star’s radial motion; This indicated the existence of an exoplanet with approximately 3 Earth masses around the star. However, later observations also refuted this discovery and showed that the previously observed radial oscillations were causing the star to brighten. Recent studies have confirmed that there are no planets near Barnard’s star that are larger than 70% of Earth and potentially habitable.

Since most red dwarfs have planets, this makes Barnard’s star a bit unusual. For example, the star Kepler-42, which is similar in size and age to Barnard’s star, has at least three exoplanets. Thus, while Barnard’s star ceases to be a strong candidate for extraterrestrial life, a recent study made it possible to make detailed observations of this star in search of signs of an extraterrestrial signal.

The five hundred meter FAST radio telescope was used in the study. The Chinese telescope has a similar antenna design to the Arecibo observatory, but its dimensions are much larger. FAST is particularly sensitive to frequency ranges, making it a good tool for searching for extraterrestrial life.

During the study of Barnard’s star, the astronomer was looking for narrow-band radiation that would be visible if an alien civilization sent radio communications in our direction. The team focused their research on signals from the hypothetical super-Earth Barnard b and took into account the Doppler effect caused by the relative motion between it and the Earth.

As you might expect, the search found no trace of an extraterrestrial signal. However, this work was mainly a test of the capabilities of the FAST telescope. Future studies, particularly those targeting nearby stars with proven habitable zone planets, will have a better chance of detecting the signals. Source