An international team of astronomers has detected an interesting radio signal that appears to be originating from a nearby star system.
The signal was seen on May 15, 2015, by the RATAN-600 radio telescope in Zelenchukskaya, Russia, and it seems to be coming from HD 164595, a Sun-like star about 95 light-years away. The team has tracked the system for 15 months, and so far there have not been any repetitions.
HD 164595 is orbited by a warm-Neptune exoplanet. It has 16 times the mass of Earth and orbits its star every 40 days, making it too hot for life to have formed there. The spike in the radio signal was very powerful and it fits the profile for an artificial transmission, with only a one in 5,000 chance of it being a fluke of the instrument.
These facts are promising, but they don’t mean that it’s a signal from an alien civilization. Earthly radio interferences could explain this unique signal; sometimes even microwave ovens cause trouble for radio telescopes!
Another likely explanation is that the star acted as a lens and magnified a radio signal from a background source, making it appear that the signal was actually local. Sometimes, natural phenomena might appear artificial in origin, especially if we have not discovered anything like it before. For example, when first discovered, the pulsating neutron stars known as pulsars were nicknamed Little Green Men.
According to GeekWire, Douglas Vakoch, president of METI International, said his research group would start monitoring HD 164595 as soon as possible. The Boquete Optical SETI Observatory and the Allen Telescope Array will start keeping an ear on the system. Vakoch was responsible for the follow-up observations of Tabby’s Star last year.
Although the SETI observations are happening, some scientists are skeptical. Speaking to GeekWire, senior SETI astronomer Seth Shostak said: “This is a bit of a puzzling story, as the Russians found this signal a year ago or so, but just didn’t let others know. That’s not good policy, as what you really want is confirmation at another telescope, but… Is it real? The signal may be real, but I suspect it’s not ET.”
The observations will be presented later this month at the International Astronautical Congress.