Astronomers revealed the origin of the BLC1 mysterious signal, which was discovered in December last year by the radio telescope as part of the Breakthrough Listen project. It was originally assumed that an unknown astrophysical process could be the source of the signal or a possible alien civilization, but a deeper analysis showed that BLC1 is most likely a hindrance of earthly origin. The results of the study are published in the Nature Astronomy magazine.
The BLC1 signal was revealed when analyzing radio observations of the proximation of the Centaur, which were conducted from April 29 to May 4, 2019 with the help of a telescope in the parks Observatory (Australia). The proxima Centauro is the star to the sun and removed at a distance of 4.22 light years. It has an exoplanet of the proxima Centaurial B, which is most likely stony similarly land and is located in the habitability zone. As the astronomers identified, Blc1 came from this direction and was narrowband.
Blc1 caused interest among astronomers, since they had obvious signs of man-made origin. It had a spectrum width about one gigahertz, which could not reproduce any known astrophysical object of natural origin. The source could not be on Earth, while the frequency drift speed smoothly changed within five hours, which could indicate an orbital movement that generates the Doppler effect. Since the signal persisted several hours, it excluded aircraft and artificial satellites.
However, a deeper analysis showed that BLC1 is most likely a hindrance of earthly origin. Scientists discovered signals whose characteristics were similar to what was caught in the parks observatory. Although the researchers do not know the exact origin of the signal, BLC1 and its twins may be generated by a process called intermodulation when two frequencies are mixed together by creating a radosum. A similar phenomenon is observed when the guitar amplifier is overloaded, which creates a sound effect known as distortion. Thus, BLC1 probably represents a distortion from a device with an overloaded radio frequency amplifier.