Enigmatic signals from near star

Red dwarf Ross 128 sends periodic radio pulses

Ross 128 is a Red Dwarf, only about ten light-years away from us. From him astronomers have now received unusual radio pulses. © UPR, Arecibo / Aladdin Sky Atlas
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Strange Pulse: Astronomers have picked up unusual radio signals from the nearby star Ross 128. The Arecibo Radiotelekop registered quasi-periodic pulses in May from this red dwarf some ten light-years away. The possible cause of these radio signals is so far unclear, as the researchers report. What could be behind it, the astronomers are currently trying to find out with new observations.

As part of the "Red Dot" campaign, astronomers have been observing a series of close red dwarfs with the Arecibo radio telescope for some time now. The goal is to explore more closely the behavior and environment of these stars in order to detect undiscovered Earth-like planets in their orbits. With success: In 2016, they discovered a twin earth around our nearest neighbor, Proxima Centauri.

Periodic pulses

But in May 2017, the Red Dot researchers encountered an unexpected signal during a new observation period: "We found that we had captured some very strange signals in the ten minute spectrum of Ross 128, " says Abel Méndez of the Arecibo Radio Telescope. This Red Dwarf is 10.89 light-years from Earth.

The radio telescope picked up these radio signals in the frequency range of four to five gigahertz when it was aimed at Ross 128. "The signals consisted of broadband pulses that were unpolarized and repeated quasi-periodically, " says Méndez. In addition, the signals showed signs of relatively strong scattering. "They seem to be unique to Ross 128, " says the researcher.

Three possible explanations - no clarity

But what could be the cause of these radio pulses? In theory, apart from aliens, there are three possible explanations for how the astronomers report. However, none of them fit so well. One possibility would be that the red dwarf stars give off a special kind of flare - radiation bursts, as they occur on the sun. However, these type II flare occur in much lower frequencies and also the scattering of the signals does not fit, as the researchers explain. display

On July 16, astronomers re-observed Ross 128 with eight telescopes. The data analysis is still ongoing ... NOAO / AURA / NSF

Another possibility would be an incorrect assignment of the signals: they could come from another object in the line of sight on Ross 128. "There are no nearby objects in the field of view of Ross 128, " says M ndez. Last but not least, the mysterious radio signals could also come from satellites in high Earth orbit. "Although such interference signals are quite common, we have never seen such radio pulses from satellites, " says the astronomer.

Evaluation of new data is in progress

So far, astronomers have no plausible explanation: "We have a mystery here each of the three explanations is as good or bad as any other, " says M ndez. But he also emphasizes that this does not mean that there is an alien sign of life here. Seth Shostak from the SETI Institute is also skeptical. He thinks it is quite probable that the signal will turn out to be a direct source of terrestrial source.

To gain more clarity, the astronomers once again listened to the Red Dwarf on 16 July with the Arecibo radio telescope and seven other telescopes. On the same day, they also carried out another observation of Barnard's Star, which was only six light-years away. The evaluation of the data is still in progress and initial results are expected by the end of this week. You can be curious.

(Planetary Habitability Laboratory, University of Puerto Rico at Arecibo, 18.07.2017 - NPO)