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Keeping an Eye on Ross 128

Frank Elmore Ross (1874-1960), an American astronomer and physicist, became the successor to E. E. Barnard at Yerkes Observatory. Barnard, of course, is the discoverer of the high proper motion of the star named after him, alerting us to its proximity. And as his successor, Ross would go on to catalog over 1000 stars with high proper motion, many of them nearby. Ross 128, now making news for what observers at the Arecibo Observatory are calling “broadband quasi-periodic non-polarized pulses with very strong dispersion-like features,” is one of these, about 11 light years out in the direction of Virgo.

Any nearby stars are of interest from the standpoint of exoplanet investigations, though thus far we’ve yet to discover any companions around Ross 128. An M4V dwarf, Ross 128 has about 15 percent of the Sun’s mass. More significantly, it is an active flare star, capable of unpredictable changes in luminosity over short periods. Which leads me back to that unusual reception. The SETI Institute’s Seth Shostak described it this way in a post:

What the Puerto Rican astronomers found when the data were analyzed was a wide-band radio signal. This signal not only repeated with time, but also slid down the radio dial, somewhat like a trombone going from a higher note to a lower one.

And as Shostak goes on to say, “That was odd, indeed.”

It’s this star’s flare activity that stands out for me as I look over the online announcement of its unusual emissions, which were noted during a ten-minute spectral observation at Arecibo on May 12. Indeed, Abel Mendez, director of the Planetary Habitability Laboratory at Arecibo, cited Type II solar flares first in a list of possible explanations, though his post goes on to note that such flares tend to occur at lower frequencies. An additional novelty is that the dispersion of the signal points to a more distant source, or perhaps to unusual features in the star’s atmosphere. All of this leaves a lot of room for investigation.

We also have to add possible radio frequency interference (RFI) into the mix, something the scientists at Arecibo are examining as observations continue. The possibility that we are dealing with a new category of M-dwarf flare is intriguing and would have obvious ramifications given the high astrobiological interest now being shown in these dim red stars.

All of this needs to be weighed as we leave the SETI implications open. The Arecibo post notes that signals from another civilization are “at the bottom of many other better explanations,” as well they should be assuming those explanations pan out. But we should also keep our options open, which is why the news that the Breakthrough Listen initiative has now observed Ross 128 with the Green Bank radio telescope in West Virginia is encouraging.

No evidence of the emissions Arecibo detected has turned up in the Breakthrough Listen data. We’re waiting for follow-up observations from Arecibo, which re-examined the star on the 16th, and Mendez in an update noted that the SETI Institute’s Allen Telescope Array had also begun observations. Seth Shostak tells us that the ATA has thus far collected more than 10 hours of data, observations which may help us determine whether the signal has indeed come from Ross 128 or has another source.

“We need to get all the data from the other partner observatories to put all things together for a conclusion,” writes Mendez. “Probably by the end of this week.”

Or perhaps not, given the difficulty of detecting the faint signal and the uncertainties involved in characterizing it. If you’re intrigued, an Arecibo survey asking for public reactions to the reception is now available.

I also want to point out that Arecibo Observatory is working on a new campaign to observe stars like Ross 128, the idea being to characterize their magnetic environment and radiation. One possible outcome of work like that is to detect perturbations in their emissions that could point to planets — planetary magnetic fields could conceivably affect flare activity. That’s an intriguing way to look for exoplanets, and the list being observed includes Barnard’s Star, Gliese 436, Ross 128, Wolf 359, HD 95735, BD +202465, V* RY Sex, and K2-18.

A final note: Arecibo is now working with the Red Dots campaign in coordination with other observatories to study Barnard’s Star, for which there is some evidence of a super-Earth mass planet. More on these observations can be found in this Arecibo news release.


Comments on this entry are closed.

  • DJ Kaplan July 19, 2017, 12:05

    How common are natural causes of radio wave emissions? I think it’s best to quantify this before evaluating possible causes.

  • Raimo Kangasniemi July 19, 2017, 12:27

    Although a natural explanation seems all but certain here, what lightly troubles me is the assumption in articles so far is that one piece of evidence against the signal from being from an alien civilization is the lack of known planets and likely hostile environment around Ross 128.

    When, if we do, find alien civilizations, we might find alien civilizations that have mastered interstellar flight and have spread to multiple solar systems. Personally I would say that we are more likely to find such a civilization than one that is confined to the solar system of its origin.

    Thus SETI messages from solar systems that are unfavourable for complex life and civilizations to arise could well be received. Especially if we expect expansion over interstellar distances to happen at least partly through robotic emissaries like Von Neumann machines.

    • Andrei July 19, 2017, 13:32

      Hello Raimo
      Yes like the author I thought of a natural cause, perhaps similar to a whistler in the stellar atmosphere and magnetosphere of Ross 128.

      Von Neumann machines would worry me, we need ask if they been provided with a proper ‘stop’ command if they encounter other life.
      And not convert a world with unusual life into resources and more Van Neumann machines.
      Same problem if the machines have been sent on a mission to convert all worlds they encounter to be suitable to a lifeform that is very different than us.

      • ljk July 20, 2017, 8:40

        Don’t we humans already want to “convert” planets that we find into more Earthlike worlds? Might other intelligences find that just as scary? And watch what happens if we do run into ETI: We will be trying to convert them as well in all sorts of ways.

        • Andrei July 20, 2017, 11:57

          Yes we think about terraforming, and might even try it in the future.
          If we ever find that an alien civilisation already have claimed a world ‘nextdoor’ is cause for concern.
          Even more paranoid idea the same machines might claim most good estate in the solar system as well, before we have time to go there.
          Worst case the Van Neumann machines have been built by life with a metabolism based on hydrogen or methane for example.
          And not be programmed to recognize oxygen breathers and view Earth as a planet that need to be converted according to their programming.

          And then we have the planet trolls. ;)

          • ljk July 21, 2017, 9:45

            That comic strip you link to brings up a real and serious issue, even if most humans aren’t ready to deal with the scenario yet. But that doesn’t mean others out there aren’t already making their claims across the galaxy and there is nothing we can do about it.

          • Jeff Wright July 21, 2017, 16:15

            That’s more like claiming a lollypop by beating everyone to the first lick.

            • ljk July 24, 2017, 13:00

              That would be an oral contract which is recognized by law.

      • Ron S. July 20, 2017, 16:54

        “to convert all worlds they encounter to be suitable to a lifeform that is very different than us.”

        If you’ll excuse a little cynicism, we aren’t waiting for ETI. We’re well on the way to accomplishing this on our own.

    • ljk July 20, 2017, 8:38

      It has taken most of the existence of modern SETI to get past its initial paradigm of aliens sending radio messages from their Earthlike planetary home circling a yellow dwarf star. Would you believe that Optical SETI was not accepted for decades because the mainstream radio guys thought that since we could not send powerful laser beams at the time then aliens couldn’t either?!

      Check out this critical history of SETI for the real background story and why we have made far less progress than we should have since Ozma on one of the most important questions ever:


  • hiro July 19, 2017, 14:44

    This is probably 99.99% natural phenomenon or 0.01% artificial troll (either native or extraterrestrial). If we happen to put a huge radio transmitter on Mars, it doesn’t mean that Martian civilization exists on that planet. Anyway, there are many objects in the background too, are we 100% sure the signal coming from the star itself?

  • Ashley Baldwin July 19, 2017, 17:20

    Twinkle, twinkle little star . For one that has been known for almost a century there are still some glaring gaps in our knowledge of what makes this star tick. It’s age for one though it is believed to be an old disk star and thus up to 10 billion years old ( twice that of similarly sized Proxima Centauri ) . Being old it’s “metallicity ” should be mich lower than that of its nearer cousin . It’s rotation is unknown too though it’s great age should have led to significant magnetic breaking – dependent to some degree on whether it is fully convective or not ( as an M4 va spectrum it sits right on the dividing line between fully and partially convective ) . This impacts heavily on how it’s magnetic field is both created and interacts with its corona to produce the signature flares which could explain it radiation out out and most especially its radio output.

    Stars like the sun which have a substantial convective envelope sitting on top of a radiative core produce a predominantly toroidal magnetic field via “differential rotation” between the two seperate layers , fixed at the interface ,or tachycline. So called “Omega” field production.

    A seperate “distributed ” field is created via the convective layer proper in combination with the rotation rate of the convective layer. The so called “Alpha ” field , which increases as the proportion of the convective layer increases producing a combined “Alpha -Omega” field as the proportion of radiative to convective layers equilibates . It’s the alpha field that gets knotted up with the stellar corona in more convective ( or fully convective ) smaller stars to snare stellar wind releasing it in unpredictable outbursts as flares and CMEs which contain radiation all the way through the electromagnetic spectrum from X-Ray to radio .

    This sort of picture follows a relatively predictable course in younger M dwarfs such as Proxima, with frequent flares. Older stars such as Ross 128 are less predictable especially if their age and rotation rate is unknown. One would imagine magnetic braking induced via interaction betwen the stellar magnetic field and wind would reduce flared activity with time , and indeed seems too do this with older and larger M dwarfs . Ross 128 seems to flare less often, however with a higher potency .

    There is a third method of stellar magnetic field , the “alpha squared” field . This is seen in convective stars too, but is less dependent on rotation as convection and as such less likely to be subject to magnetic braking .

    So with atleast two and possibly even three ( if Ross 128 isn’t fully convective ) seperate magnetic fields in action and all interacting it’s impossible to exclude a flare induced explanation to the “atypical” radio output to this Methusalah star . I also think that as M dwarfs are becoming more fashionable and in focus thanks to Kepler et al , not least as potentially the easiest and thus first to have a potentially habitable planet constrained – that we will see more of these unusual findings .

    You have to go looking to find new stuff and it shows also just how little was really known about even relatively well known and neighbouring stars until recently . Another corollary to exoplanet science.

  • Zachary July 19, 2017, 19:56

    Breaking from Twitter:

    Prof. Abel Méndez‏ (@ProfAbelMendez) 6 minutes ago:

    Full explanation of the signals of #Ross128 will be given on Friday.

    2 replies 0 retweets 5 likes

    • ljk July 20, 2017, 8:35

      Why do we have to wait until Friday? That’s just teasing at this point.

  • ljk July 19, 2017, 23:16



    To quote:

    Beginning last weekend, Jon Richards swung the SETI Institute’s Allen Telescope Arrayin the direction of Ross 128, and so far has collected more than 10 hours of data. Even using the massive Arecibo antenna, the detected signal was weak, and that makes its detection with other instruments difficult. But it’s obviously important to check the signal out and, insofar as possible, see if it’s really coming from the Ross 128 star system.

    Institute scientist Gerry Harp is looking at the ATA data now, and this page will be updated with whatever findings are made. Of course it’s possible that Ross 128 will shed its anonymity and become the first star system to show good evidence of extraterrestrial intelligence. But it’s likely – at least on the basis of past experience – that we will find another, less romantic explanation for the mystery that now enshrouds this object. That, of course, is a frequent occurrence for anyone doing exploration, and hardly a cause for discouragement, but rather an incentive to continue the search.

  • RAS July 20, 2017, 5:08

    Guessing one explanation will be flares from Ross 128.

    Anyone want to guess on the other explanation?

    Prof. Abel Méndez @ProfAbelMendez

    I analyzed the #Ross128 data and reduced the explanations for the signals from many to just two. Still waiting for other observatories data.
    12:29 am · 20 Jul 2017


    Prof. Abel Méndez @ProfAbelMendez

    Full explanation of the signals of #Ross128 will be given on Friday.
    12:48 am · 20 Jul 2017


    • Ashley Baldwin July 20, 2017, 15:57

      Keep ’em wanting more !

  • Harry R Ray July 20, 2017, 9:25

    Although this is most certainly NOT the case here, it is instructional to note that the strength(or lack thereof)of these “signals” is ALMOST EXACTLY WHAT YOU WOULD EXPECT TO SEE from “leakage” originating from THAT DISTANCE. The problem with “leakage” has always been the EXTREMELY SMALL SAMPLE SIZE for SETI targets at that range. When FAST comes online, one of its FIRST TASKS should be long term observations of Ross 128, just for calibration purposes, in hope that it can SIGNIFIGANTLY INCREASE the “leakage” target sample size.

  • RAS July 21, 2017, 12:10

    Prof. Abel Méndez @ProfAbelMendez
    The #Weird!Signal was most likely caused by one or more geostationary satellites. The shape of the signal is still under investigacion.4:38 pm · 21 Jul 2017


    • Ashley Baldwin July 21, 2017, 17:59

      Blimey. And I thought that flare induced activity was a plausible if somewhat anticlimatic explanation.

    • ljk July 22, 2017, 19:48

      They have not said which geosynchronous satellites are causing the signals; it is almost a guess. And I thought there were strict rules about transmitting near, around, on, or over Arecibo, being such a sensitive astronomical radio instrument.

      This is not over and the media and scientists better not just write it off because one astronomer thinks they are geosat signals.

    • ljk July 25, 2017, 9:20

      This is just what happened with that signal from HD 164595 last year in Russia. They also said it was a satellite, probably an old Soviet spysat – yet they never provided an actual identification and then dropped the whole subject, while the media dutifully parroted whatever they were told.


      When they match the Ross 128 signals with an actual geosat and identify it, then they can make that claim. Until then, the mystery is not solved.

  • stephen July 21, 2017, 21:29

    Here’s a comparison:
    SETI is like going into a building which may be a casino. But it’s dark, and you don’t know if anybody else is there. You sit down at a table, but you don’t know if anybody else is at the table.

    You do something which may be related to whatever game the others are playing, and you wait a few hundred years before the others at the table play their moves.

    You might not recognize their moves when they make them.

    At the end of the game you receive something which may or may not be your winnings, and their idea of winnings might be very different from your own.

    And people might disagree about whether you have really “won”.
    You might “technically” win, whatever that means.

    So I think we can wait a while before doing SETI.

    Arthur C. Clarke, in “Fountains of Paradise”, I think, had a station in the outer solar system scanning the entire sky constantly, far away from Earth’s noisy environment, and that seemed reasonably efficient.

    • ljk July 24, 2017, 9:21

      Or we put a SETI station on the lunar farside, giving us 2,160 miles of lunar rocks to block signals from Earth.

    • ljk July 24, 2017, 9:22

      Of course Optical SETI does not have the interference problems that Radio SETI does. Astronomers could detect an Optical signal in broad daylight if it is strong enough.

    • ljk July 25, 2017, 11:18

      Time for this refresher on various methods of ETI signaling and detection again:


  • ljk July 28, 2017, 11:41

    Detecting Alien Life Will Likely Be a Protracted Process, Not a Eureka Moment

    Scientific discovery most often comes through incremental progress rather than epiphanies, and there’s no reason to suggest discovering alien intelligence will be different.

    By Elizabeth Howell

    July 25, 2017

    1:24 PM EDT


  • ljk October 24, 2017, 14:22


    Breakthrough Listen Follow-up of the Reported Transient Signal Observed at the Arecibo Telescope in the Direction of Ross 128

    Press Release – Source: astro-ph.SR

    Posted October 23, 2017 8:48 PM

    We undertook observations with the Green Bank Telescope, simultaneously with the 300 meter telescope in Arecibo, as a follow-up of a possible flare of radio emission from Ross 128.

    We report here the non-detections from the GBT observations in C band (4-8 GHz), as well as non-detections in archival data at L band (1.1-1.9 GHz). We suggest that a likely scenario is that the emission comes from one or more satellites passing through the same region of the sky. [Which satellites exactly?]

    J. E. Enriquez, A. Siemion, R. Dana, S. Croft, A. Méndez, A. Xu, D. DeBoer, V. Gajjar, G. Hellbourg, H. Isaacson, M. Lebofsky, D. H. E. MacMahon, D. C. Price, D. Werthimer, J. Zuluaga

    (Submitted on 23 Oct 2017)

    Comments: 6 pages, 2 figures. Accepted to International Journal of Astrobiology

    Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

    Cite as: arXiv:1710.08404 [astro-ph.SR] (or arXiv:1710.08404v1 [astro-ph.SR] for this version)

    Submission history

    From: Jesus Emilio Enriquez

    [v1] Mon, 23 Oct 2017 17:52:26 GMT (3495kb,D)


    Astrobiology, SETI