text: An Interesting SETI Candidate in Hercules 
   
   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. 
   
   Image: The RATAN-600 radio telescope in Zelenchukskaya. Credit: Wikimedia Commons. 
   
   Here I’m drawing on a presentation forwarded to me by Claudio Maccone, from which I learn that the team behind the detection was led by N.N. Bursov and included L.N. Filippova, V.V. Filippov, L.M. Gindilis, A.D. Panov, E.S. Starikov, J. Wilson, as well as Claudio Maccone himself, the latter a familiar figure on Centauri Dreams. The work is to be discussed at a meeting of the IAA SETI Permanent Committee, to be held during the 67th International Astronautical Congress (IAC) in Guadalajara, Mexico, on Tuesday, September 27th, 2016, 
   
   What we know of HD 164595 is that it is a star of 0.99 solar masses at a distance of roughly 95 light years in the constellation Hercules, and an estimated age of 6.3 billion years. Its metallicity is almost identical to that of the Sun. A known planet in this system, HD 164595 b, is 0.05 Jupiter mass with a period of 40 days, considered to be a warm Neptune on a circular orbit. There could, of course, be other planets still undetected in this system. 
   
   Image: Strong signal from the direction of HD 164595. “Raw” record of the signal together with expected shape of the signal for point-like source in the position of HD 164595. Credit: Bursov et al. 
   
   From the presentation: 
   
   The estimated probability ~2 X 10-4 to simulate the signal from the direction of the HD164595 by signal-like noise is small, therefore HD164595 is good candidate SETI. Permanent monitoring of this target is needed. 
   
   All of which makes excellent sense. We can’t claim the detection of an extraterrestrial civilization from this observation. What we can say is that the signal is interesting and merits further scrutiny. ||||| Mikhail Turnovskiy/Alamy Stock Photo 
   
   Are you there, ET? Recent news of a spike in radio signals that could fit the profile for an intelligent, extraterrestrial source has SETI astronomers across the globe swinging their radio dishes in hopes of confirming the detection. Although so far they have all come back empty-handed, two observatories will follow up on the tantalising signal again tonight. 
   
   The signal was detected on May 15, 2015 by a radio telescope operated by the Russian Academy of Science. It appeared to come from the star HD 164595, a sun-like star located roughly 95 light-years from Earth. The system has only one known planet: a warm Neptune, so called because it is gaseous like Neptune but orbits its star in only 40 days. But the star probably has other planets — perhaps rocky ones — as well. 
   
   The researchers speculate that such a bright signal, if real, could have been produced by a radio beacon built by an intelligent civilisation. 
   
   If that beacon is transmitting radio waves in all directions, the energy it would need to produce is a whopping 1020 watts, says Seth Shostak, an astronomer at the SETI Institute in California. “That’s a big energy bill even if you’re getting a bulk discount from your local supplier,” he jokes. “It’s hundreds of times more than all the energy falling on the Earth from sunlight.” 
   
   That means the hypothetical beings responsible might be what SETI scientists call a Kardashev Type II civilisation, so advanced that they can tap all of the energy being produced by their host star. 
   
   If instead the beacon was targeted at Earth, then the power needed drops to 1013 watts, Shostak says. “That is more or less the total amount of energy used by humankind — all the cars, all the planes, all the electronic devices, everything,” Shostak says. “This is not a high-school science project.” 
   
   That would make the senders a Kardashev Type I civilisation, able to harness all the starlight that falls on its home planet. 
   
   Jumping to conclusions? 
   
   Although it’s fun to speculate, it’s far more likely that the signal isn’t an extraterrestrial beacon at all, but actually earthly interference. Radio telescopes have been known to pick up rogue signals – everything from flushing toilets to cell phones. Just last year, astronomers at the Parkes Radio Telescope in Australia traced a mysterious type of radio signal to two on-site microwave ovens. 
   
   “In SETI part of the problem is that you have a civilisation that is producing signals that can mess you up all the time – and that civilisation is called humanity,” Shostak says. 
   
   So before astronomers jump to any conclusion, they’re attempting to detect the signal again. Last night, the SETI Institute used the Allen Telescope Array in northern California to track the star. They saw nothing, but will observe again tonight. 
   
   That lack of detection doesn’t close the book on an extraterrestrial civilisation just yet. “You can’t say because you didn’t find something that there’s nothing there,” Shostak says. “Say Captain Cook sailed around all day in the South Pacific and he didn’t find any new islands. That doesn’t prove that there are no new islands, it just proves that he didn’t find any that day.” 
   
   A civilisation might also try to send signals at multiple frequencies, says Douglas Vakoch, the president of METI International, a group that wants to send messages to ET as well as detect their signals. Perhaps last night, they simply weren’t broadcasting at the same frequency we initially detected. 
   
   Read more: SETI looks at red dwarf stars in its search for ancient aliens 
   
   “If you really want to communicate a lot of information there are advantages to sending at optical frequencies,” he says. “So we are planning to observe the star from our optical SETI observatory in Panama this evening. We tried last night but the weather didn’t cooperate.” 
   
   Still, Vakoch is not particularly optimistic that they will find anything. “I think the likely outcome of this is that there’s no indication that it’s ET, but it provides a critical preparation for a day we may really discover intelligence out there,” he says. “We can speculate as much as we want about whether there’s intelligence out there in the cosmos, but unless we find something interesting and do a rigorous follow-up, we’ll never know.” 
   
   An earlier version of this story misstated the distance to the star. This has been corrected. ||||| The SETI Institute is using the Allen Telescope Array in Northern California in an attempt to confirm an intriguing signal coming from the star HD 164595. 
   
   A powerful signal has been spotted coming from the vicinity of a sunlike star, and now astronomers are trying to figure out what it means. 
   
   In May 2015, researchers using a radio telescope in Russia detected a candidate SETI (search for extraterrestrial intelligence) signal that seems to originate from HD 164595, a star system that lies about 94 light-years from Earth, the website Centauri Dreams reported over the weekend. 
   
   The astronomers have not yet published a study about the detection; they plan to discuss it next month at the 67th International Astronautical Congress (IAC) in Guadalajara, Mexico, according to Centauri Dreams' Paul Gilster, who wrote that one of the team members forwarded him the IAC presentation. [13 Ways to Hunt Intelligent Alien Life] 
   
   
   
   Yes - We may not have found them yet, but they're out there. 
   
   No - Aliens are just part of science fiction. 
   
   I'm not sure 
   
   
   
   HD 164595 is known to harbor one planet — a roughly Neptune-mass world that orbits too close to the star to support life as we know it. However, it's possible that other worlds lurk undiscovered in the system, said astronomer Seth Shostak of the SETI Institute in Mountain View, California, who is not part of the detection team. 
   
   To be clear: Nobody is claiming that aliens beamed out this signal. But that is one of the possible scenarios at the moment, Shostak told Space.com. 
   
   The scientists who made the detection are respected researchers, and the signal is strong enough that it's probably not just random noise, Shostak said. Furthermore, the signal is consistent with something an alien civilization might send out — and if aliens did indeed do it, they are certainly far more advanced than we are, he added. 
   
   Based on the received signal's characteristics, aliens would have to generate about 100 billion billion watts of energy to blast it out in all directions. And they'd still have to produce more than 1 trillion watts if they beamed it only to Earth for some reason, Shostak said. 
   
   "The first number is hundreds of times more than all the sunlight falling on Earth," he said. "That's a very big energy bill." 
   
   The SETI Institute focused the Allen Telescope Array (ATA), a system of radio dishes in Northern California, at HD 164595 Sunday night (Aug. 28) and plans to do so again tonight (Aug. 29), Shostak said. He certainly hopes the ATA finds something that would suggest ET is behind the signal, but he said he suspects there's a more prosaic explanation. 
   
   For example, it's possible that interference by an Earth-orbiting satellite or something else close to home is responsible, Shostak said. Indeed, he said that such "terrestrial interference" would be his bet, if we ever do learn what caused the signal. 
   
   But, sadly, it's very possible that we'll never know. The Russia-based team apparently observed the HD 164595 system 39 different times and only detected the signal once, Shostak said. If nobody sees it again, it will probably remain a mystery, much like the famous "Wow!" signal of 1977. 
   
   "Without a confirmation of this signal, we can only say that it's 'interesting,'" Shostak wrote today in a blog post about the candidate signal detection. 
   
   Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com. ||||| An international team of scientists from the Search for Extraterrestrial Intelligence (SETI) is investigating mysterious signal spikes emitting from a 6.3-billion-year-old star in the constellation Hercules—95 light years away from Earth. The implications are extraordinary and point to the possibility of a civilization far more advanced than our own. 
   
   The unusual signal was originally detected on May 15, 2015, by the Russian Academy of Science-operated RATAN-600 radio telescope in Zelenchukskaya, Russia, but was kept secret from the international community. Interstellar space reporter Paul Gilster broke the story after the researchers quietly circulated a paper announcing the detection of “a strong signal in the direction of HD164595.” 
   
   READ ALSO: NASA Director Reveals the 4 Places Most Likely to Have Alien Life In Our Solar System 
   
   The mysterious star’s designation is HD164595, and it’s considered to be sun-like in nature with a nearly identical metallic composition to our own star. So far, a single Neptune-like (but warmer) planet has been discovered in its orbit—HD 164595 b. But as Gilster explained, “There could, of course, be other planets still undetected in this system.” 
   
   Decorated Italian SETI researcher and mathematician Claudio Maccone along with Russia’s Nikolai Bursov of the Special Astrophysical Observatory are the principal scientists working on the apparent discovery. They claim that “permanent monitoring of this target is needed.” 
   
   “The signal conceivably fits the profile for an intentional transmission from an extraterrestrial source,” said Alan Boyle, author of The Case for Pluto who reported the story for Geekwire. “In any case, the blip is interesting enough to merit discussion by those who specialize in the search for extraterrestrial intelligence.” 
   
   The signal’s strength indicates that if it in fact came from a isotropic beacon, the power source would have to be built by a Kardashev Type II civilization. (The Kardashev scale is used to determine the progress of a civilization’s technological development by measuring how much energy was used to transmit an interstellar message.) An ‘Isotropic’ beacon means a communication source emitting a signal with equal power in all directions while promoting signal strength throughout travel. 
   
   In his acclaimed work “Transmission of Information by Extraterrestrial Civilizations,” Soviet astronomer Nikolai Kardashev explained that a Type II civilization would be able to harness the energy of their entire host star. The most common hypothetical example of this would be a Dyson Sphere—which is a massive artificial structure that could completely encapsulate a star and transfer the energy to a nearby planet. 
   
   Basically, if the signal was beamed out into the galaxy without aim or direction, that would require an enormous amount of power to actually be detected. But what if the signal was beamed specifically at our solar system? Well, that would require less energy and could indicate the presence of a Kardashev Type I civilization—meaning that it could be a highly technological, contemporary society that harnesses the solar energy emitted by its local star, much like our planet does with solar panels. This particular civilization’s social structure is theorized to be completely globalized and interconnected. 
   
   “The signal is provocative enough that the RATAN-600 researchers are calling for permanent monitoring of this target,” said Gilster. And that’s exactly what is transpiring. As of last night, the SETI institute is diverting its Allen Telescope Array in northern California to investigate while their counterparts at METI International (Messaging Extraterrestrial Intelligence) will use Panama’s Boquete Optical Observatory. 
   
   The detection of the mysterious signal and the ensuing investigations will be discussed at the IAA SETI Permanent Committee during the 67th International Astronautical Congress in Guadalajara, Mexico, on September 27—the same day and location where Elon Musk will reveal his plans to colonize Mars. The Observer will be following up on both these stories from the Congress. 
   
   Robin Seemangal focuses on NASA and advocacy for space exploration. He was born and raised in Brooklyn, where he currently resides. Find him on Instagram for more space-related content: @nova_road. ||||| It remains only the barest of probabilities that astronomers have just found evidence of extraterrestrial, intelligent life. Nevertheless, in the community of astronomers and other scientists who use radio telescopes to search the heavens for beacons of life there is considerable excitement about a new signal observed by a facility in Russia. 
   
   According to Paul Gilster, author of the Centauri Dreams website, the Italian astronomer Claudio Maccone and other astronomers affiliated with the search for extraterrestrial intelligence have detected "a strong signal in the direction of HD164595." HD 164595 is a star of 0.99 solar masses about 95 light years from Earth, with an estimated age of 6.3 billion years. The system is known to have at least one planet, HD 164595 b, which is similar in size to Neptune and orbits its star in 40 days. Other planets may exist in the system as well. 
   
   The observation was made with the RATAN-600 radio telescope in Zelenchukskaya, in southern Russia, Gilster reports. He cautioned that the evidence is very preliminary: 
   
   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. 
   
   More information may be forthcoming soon. According to Gilster, the discovery and work to understand its origin will be discussed at a SETI committee meeting during the 67th International Astronautical Congress in Guadalajara, Mexico, on Tuesday, September 27. 
   
   Ars contacted Nick Suntzeff, a Texas A&M University astronomer, for insight into what this signal at 11Ghz might be if it were not of alien origin. "If this were a real astronomical source, it would be rather strange," Suntzeff told Ars. Although there are mysterious, high-energy astrophysical phenomenon called “fast radio bursts” that are seen at a few gigahertz, they last only 10 milliseconds or so (this event lasted longer). Unfortunately, he said, there is no information given about the strength of the signal as a function of frequency. 
   
   Suntzeff added that he would not be surprised if the signal was due to a terrestrial origin, because it was observed in part of the radio spectrum used by the military. "God knows who or what broadcasts at 11Ghz, and it would not be out of the question that some sort of bursting communication is done between ground stations and satellites," he said. "I would follow it if I were the astronomers, but I would also not hype the fact that it may be at SETI signal given the significant chance it could be something military." ||||| A star system 94 light-years away is in the spotlight as a possible candidate for intelligent inhabitants, thanks to the discovery of a radio signal by a group of Russian astronomers. 
   
   
   
   The RATAN-600 radio telescope, credit: nat-geo.ru 
   
   HD 164595, a solar system a few billion years older than the Sun but centered on a star of comparable size and brightness, is the purported source of a signal found with the RATAN-600 radio telescope in Zelenchukskaya, at the northern foot of the Caucasus Mountains. This system is known to have one planet, a Neptune-sized world in a very tight orbit, making it unattractive for life. However, there could be other planets in this system that are still undiscovered. 
   
   The signal seems to have been discussed in a presentation given by several Russian astronomers as well as Italian researcher, Claudio Maccone, the Chair of the International Academy of Astronautics Permanent SETI Committee. Maccone has recently sent an email to SETI scientists in which he describes this presentation, including the signal ascribed to star system HD 164595. 
   
   Could it be a transmission from a technically proficient society? At this point, we can only consider what is known so far. This is a technical story, of course. 
   
   First, is the detected signal really coming from the direction of HD 164595? The RATAN-600 is of an unusual design (a ring on the ground of diameter 577 meters), and has an unusual “beam shape” (the patch of sky to which it is sensitive). At the wavelength of the reported signal, 2.7 cm – which is equivalent to a frequency of 11 GHz – the beam is about 20 arcsec by 2 arcmin. In other words, it’s a patch that’s highly elongated in the north-south direction. 
   
   The patch from which the signal seems to be coming agrees in the east-west direction (the narrow part of the beam) with HD 164695’s sky coordinates, so that’s the basis of the assumption by the discoverers that this is likely to be coming from that star system. But of course, that’s not necessarily the case. 
   
   Second is the question of the characteristics of the signal itself. The observations were made with a receiver having a bandwidth of 1 GHz. That’s a billion times wider than the bandwidths traditionally used for SETI, and is 200 times wider than a television signal. The strength of the signal was 0.75 Janskys, or in common parlance, “weak.” But was it weak only because of the distance of HD 164595? Perhaps it was weak because of “dilution” of the signal by the very wide bandwidth of the Russian receiver? Just as a potpie, incorporating lots of ingredients, can make guessing the individual foodstuffs more difficult, a wide-bandwidth receiver can dilute the strength of relatively strong narrow-band signals. 
   
   Now note that we can work backwards from the strength of the received signal to calculate how powerful an alien transmitter anywhere near HD 164595 would have to be. There are two interesting cases: 
   
   (1) They decide to broadcast in all directions. Then the required power is 1020 watts, or 100 billion billion watts. That’s hundreds of times more energy than all the sunlight falling on Earth, and would obviously require power sources far beyond any we have. < 
   
   (2) They aim their transmission at us. This will reduce the power requirement, but even if they are using an antenna the size of the 1000-foot Arecibo instrument, they would still need to wield more than a trillion watts, which is comparable to the total energy consumption of all humankind. 
   
   Both scenarios require an effort far, far beyond what we ourselves could do, and it’s hard to understand why anyone would want to target our solar system with a strong signal. This star system is so far away they won’t have yet picked up any TV or radar that would tell them that we’re here. 
   
   Enter the Allen Telescope Array 
   
   The chance that this is truly a signal from extraterrestrials is not terribly promising, and the discoverers themselves apparently doubt that they’ve found ET. Nonetheless, one should check out all reasonable possibilities, given the importance of the subject. 
   
   Consequently, the Allen Telescope Array (ATA) was swung in the direction of HD 164595 beginning on the evening of August 28. According to our scientists Jon Richards and Gerry Harp, it has so far not found any signal anywhere in the very large patch of sky covered by the ATA. 
   
   However, we have not yet covered the full range of frequencies in which the signal could be located, if it’s of far narrower bandwidth than the Russian 1 GHz receiver. We intend to completely cover this big swath of the radio dial in the next day or two. A detection, of course, would immediately spur the SETI and radio astronomy communities to do more follow-up observations. 
   
   We will continue to monitor this star system with the Array. 
   
   One particularly noteworthy thing about this discovery is the fact that the signal was apparently observed in May, 2015 (it seems that this was the only time in 39 tries that they saw this signal). The discoverers didn’t alert the SETI community to this find until now, which is not as expected. According to both practice and protocol, if a signal seems to be of deliberate and extraterrestrial origin, one of the first things to do is to get others to attempt confirming observations. That was not done in this case. 
   
   So what’s the bottom line? Could it be another society sending a signal our way? Of course, that’s possible. However, there are many other plausible explanations for this claimed transmission – including terrestrial interference. Without a confirmation of this signal, we can only say that it’s “interesting.” 
   
   August 30, 2016 
   
   We spent a second day looking for radio emission from HD 164595, this time stepping across the radio dial to cover all the frequencies observed by the Russian astronomers. We failed to see any signal greater than 0.1 Janskys in a bandwidth of 100 MHz, whereas the claim by the Russians was a signal of 0.75 Janskys. Despite the fact that it would be both exciting and enticing to say that this signal was really from aliens inhabiting HD 164595, that would be an unwarranted assertion given the inability to confirm this signal. In the SETI business, one telescope is not enough and an array is even better. 
   
   August 31, 2016 
   
   An article that quotes the Russian news agency TASS is suggesting that the signal found using the Russian RATAN-600 radio telescope is, indeed, terrestrial interference. The article, which can be found here – http://tass.com/science/896683 -- says in part “Director of the Institute of Applied Astronomy at the Russian Academy of Sciences Alexander Ipatov told TASS that back at the Soviet period he had been part of a group of young astronomers at the special astrophysical observatory searching for signals from extraterrestrial civilizations. ‘We, indeed, discovered an unusual signal. However, an additional check showed that it was emanating from a Soviet military satellite, which had not been entered into any of the catalogs of celestial bodies,’ Ipatov said.” 
   
   As noted in the accompanying write-up, we have been unable to find this signal using our Allen Telescope Array. That would be consistent, of course, with it being terrestrial interference, such as a military satellite. However, there seems to be some contradiction in the Russian response quoted above, as the signal was labeled as being measured in May, 2015, long after the demise of the Soviet Union. 
   
   Later today, a statement from the Special Astrophysical Observatory of the Russian Academy of Sciences was made: https://www.sao.ru/Doc-en/SciNews/2016/Sotnikova/ The statement concludes with this sentence: “It can be said with confidence that no sought-for signal has been detected yet.”
target: – Are aliens living 95 light-years away reaching out to say hello? OK, probably not, but astronomers are nevertheless intrigued by an unusual signal reported out of Russia, reports the Observer. It seems to be coming from the general vicinity of an ancient star in the constellation Hercules known as HD164595, which has at least one planet in its orbit. The signal was detected by the RATAN-600 radio telescope in Zelenchukskaya on May 15, 2015, but only just made public in a paper, reports the website Centauri Dreams. The Search for Extraterrestrial Intelligence has begun looking into it, and "the signal is provocative enough that the RATAN-600 researchers are calling for permanent monitoring of this target," writes Paul Gilster. The reason it's generating so many headlines on science websites is that the signal has the hallmarks of one that would come an advanced civilization. After all, it would take an enormous amount of energy to blast it out deliberately, notes Space.com. Unfortunately for sci-fi fans, the best bet is that the signal is the result of some kind of interference from Earth, reports New Scientist. It might even come from our own military's communications, reports Ars Technica. "Could it be another society sending a signal our way?" asks SETI's Seth Sostak in a blog post. "Of course, that’s possible." But plenty of other explanations exist, and "without a confirmation of this signal, we can only say that it’s 'interesting.'" Astronomers will discuss the signal at a SETI meeting on Sept. 27. (SETI is also looking for signals from another star.)