Barnard’s Star, a diminutive red dwarf just six light-years away from Earth, remained unnoticed until 1916 when E. E. Barnard’s keen eye detected its unusually high proper motion. Intriguingly, old Harvard Observatory photographic plates from the late 1800s did capture its faint presence, but it went unnoticed due to its small and dim stature. Since its discovery, Barnard’s Star has been under the scientific spotlight as one of the most scrutinized red dwarfs.
What adds a layer of fascination is Barnard’s Star being one of the earliest stars that was thought to host planets. Going back to the 1970s, initial studies hinted at the presence of gas giants orbiting it, only to be overturned by subsequent observations. In 2018, astronomers, through radial motion measurements, hinted at the existence of a close-orbiting super-Earth weighing approximately three times the mass of our home planet. Yet, this discovery too was challenged, attributing the observed radial fluctuations to solar flares. Recent investigations have now firmly established that Barnard’s Star lacks any close-orbiting or potentially habitable planets larger than 70% of Earth’s size.
This peculiarity sets Barnard’s Star apart because most red dwarfs are known to have planets. For instance, Kepler-42, a red dwarf star akin in size and age to Barnard’s Star, boasts at least three terrestrial planets. Therefore, while the prospect of alien life around Barnard’s Star appears dim, a recent study published on the preprint server arXiv delved into detailed observations of the star, searching for potential extraterrestrial signals.
To conduct this study, scientists harnessed the impressive capabilities of the Five-hundred-meter Aperture Spherical Telescope (FAST), a Chinese observatory resembling the Arecibo Observatory but on a much grander scale. FAST’s sensitivity in frequency ranges crucial for long-distance communication made it an ideal tool for the hunt for extraterrestrial beings.
The research team combed through data from Barnard’s Star, keeping an eye out for narrow-band emissions—signals that could be indicative of deliberate radio messages beamed in our direction by an alien civilization. They even devoted attention to signals that might originate from the hypothetical super-Earth, Barnard’s Star b, adjusting for Doppler shifts stemming from its relative motion concerning Earth.
As one might anticipate, the study returned empty-handed, failing to unearth any trace of an alien signal. Nonetheless, it’s worth noting that this study primarily served as a test of FAST’s capabilities. Future endeavors, especially those targeting nearby stars harboring confirmed planets in their habitable zones, hold greater promise in our quest for potential cosmic neighbors.
Source: Universe Today