Update on that unusual signal from a distant star

[ Update: As many suspected, it appears the signal was of terrestrial origin: Turns out the signal astronomers saw was “strong” because it came from Earth – Ars Technica.

+ Here is a brief video from Seth Shostak:


That odd signal from a star 94 light years away is fun to ponder but very unlikely to have been sent by an alien civilization. Here was the first report to hit the Internet: An Interesting SETI Candidate in Hercules – Paul Clister/Centauri Dreams

A candidate signal for SETI is a welcome sign that our efforts in that direction may one day pay off. An international team of researchers has announced the detection of “a strong signal in the direction of HD164595” in a document now being circulated through contact person Alexander Panov. The detection was made with the RATAN-600 radio telescope in Zelenchukskaya, in the Karachay–Cherkess Republic of Russia, not far from the border with Georgia in the Caucasus.

The signal was received on May 15, 2015, 18:01:15.65 (sidereal time), at a wavelength of 2.7 cm. The estimated amplitude of the signal is 750 mJy.

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.

No one has yet seen a subsequent pulse from the star and, as mentioned above, there are various background sources that could have generated the original signal. Here are some updates on the analyses and observations from other radio telescopes: