I'm sure that many of you have seen the news reports of a "SETI signal" detected from the star HD 164595
I was one of the many people who received the the email with the subject "Candidate SETI SIGNAL DETECTED by Russians from star HD 164595 by virtue of RATAN-600 radio telescope." Since the email did come from known SETI researchers, I looked over the presentation. I was unimpressed. In one out of 39 scans that passed over star showed a signal at about 4.5 times the mean noise power with a profile somewhat like the beam profile. Of course SETI@home has seen millions of potential signals with similar characteristics, but it takes more than that to make a good candidate. Multiple detections are a minimum criterion.
Because the receivers used were making broad band measurements, there's really nothing about this "signal" that would distinguish it from a natural radio transient (stellar flare, active galactic nucleus, microlensing of a background source, etc.) There's also nothing that could distinguish it from a satellite passing through the telescope field of view. All in all, it's relatively uninteresting from a SETI standpoint.
But, of course, it's been announced to the media. Reporters won't have the background to know it's not interesting. Because the media has it, and since this business runs on media, everyone will look at it. ATA is looking at it. I assume Breakthrough will look at it. Someone will look at it with Arecibo, and we'll be along for the ride. And I'll check the SETI@home database around that position. And we'll all find nothing. It's not our first time at this rodeo, so we know how it works.
and Dr. Korpela wrote:
We believe a signal when
*It is persistent. It appears at the same spot in the sky in multiple observations.
*It only comes from one spot in the sky.
*If we reobserve the target, the signal is still there.
Things that add to believability
*Its frequency/period/delay does not correspond to known interference.
*Its Doppler Drift rate indicates that it is exactly frequency stable in the frame of the center of mass of the solar system
*Its properties (bandwidth, chirp rate, encoding) indicate intelligent origin.
Unfortunately the observing method used by the Russian team does not permit many of these things to be determine. 1. The signal was not persistent. 2. The signal was gone when the target was reobserved. 3. The signal frequency/period/delay cannot be determined. 4. The signal Doppler drift rate is unknown. 5. Many sources of interference, including satellites, are present in the observing band.