An international team of researchers has revealed the detection of “a strong signal” coming from the direction of a star in the constellation of Hercules (HD164595). The signal was picked up by the RATAN-600 radio telescope at the Special Astrophysical Observatory of the Russian Academy of Science.
As always, there are a number of possible mundane explanations for the 2.7cm wavelength ‘transmission’ – which was originally detected last year on May 15 – ranging from passing satellites through to micro-lensing of a background source. But it’s still definitely worth looking for a repetition of the signal, and SETI researchers are no doubt cautiously excited.
No one is claiming that this is the work of an extraterrestrial civilization, but it is certainly worth further study. Working out the strength of the signal, the researchers say that if it came from an isotropic beacon, it would be of a power possible only for a Kardashev Type II civilization. If it were a narrow beam signal focused on our Solar System, it would be of a power available to a Kardashev Type I civilization. The possibility of noise of one form or another cannot be ruled out, and researchers in Paris led by Jean Schneider are considering the possible microlensing of a background source by HD164595. But the signal is provocative enough that the RATAN-600 researchers are calling for permanent monitoring of this target.
HD 164595 is just under 100 light years from Earth, and an exoplanet (HD 164595 b) has previously been detected orbiting the star. As Paul Gilster notes at Centauri Dreams, the planet is “0.05 Jupiter mass with a period of 40 days, considered to be a warm Neptune on a circular orbit”. But there could also be other, still undetected planets also orbiting HB 164595.
Geekwire science journalist Alan Boyle spoke with SETI researcher Douglas Vakoch about the announcement, and he confirmed that his team will be taking a look at HD 164595 as soon as possible, using the Boquete Optical SETI Observatory in Panama. Not only purely out of interest and excitement, but also because SETI protocols require it:
Standard SETI protocols call for confirmation of possible signals from a separate observatory. This helps ensure that the original signal didn’t arise from a technical glitch in the original observatory, and it helps rule out a hoax perpetuated by some enterprising graduate students targeting a SETI experiment.
In the past, plans for SETI follow-up observations have focused on confirmation of the original signal, seeking a repeat signal at the same frequency. That’s a critical step for confirmation – and we don’t yet have evidence that this sort of follow-up has happened for HD 164595.
In addition, we need to be alert to the possibility than if we do really find a signal from an advanced civilization, they are also transmitting at other frequencies than the one where we first detected them. That’s why it’s so important to prepare for follow-up SETI observations at both radio and optical frequencies, to be launched as soon as we detect a credible candidate signal at any frequency.
Be sure to read the full articles at both Centauri Dreams and GeekWire via the links below.