The LONGEST DX? Possible Alien Signal from Proxima Centauri

BLC-1 is the designation for a narrowband emission that --may-- be ET's from Proxima Centauri. However, it has not been received in later observing sessions and is most likely terrestrial interference. The observation was made by the Parkes telescope in Australia and remotely analyzed at Penn State. Here's the info (photo is the Parkes telescope):

Alien hunters detect mysterious radio signal from nearby star (msn.com)

 

I could work this out myself but I am too lazy ..

What would the ERP have to be for a signal from Proxima Centauri to be heard here?

 

We need the frequency information first.

 

If you had DSN style 70-meter dishes (7145 MHz) at both ends, you could have a nice CW QSO with only a 100 kW power amplifier (2 trillion watts EIRP).

 

We do not know the detection limit of the Parkes system until they publish the info. For example, we do not know the frequency of detection, and it is exceedingly unlikely to be at X band.

Your point is a good one, which is tens of KW with fair sized dishes could easily be achieved over a parsec or so distance in the microwave window. It is described as a 'beacon', if real, so this is not extraterrestrial leakage from an ET 'cell phone' of low power :->

 

980 MHz, according to the article in The Guardian.

 

According to the GUARDIAN?

My source is the National Geographic piece by Nadia Drake, which was vetted and quotes the actual people involved. No details on frequency, integration time, bandwidth.

980 MHz is a PIM frequency from the cell bands. This makes the detection exceedingly unlikely to be of extraterrestrial origin.

If you want to play with the numbers, I will get you the Parkes aperture and the aperture efficiency, but RZ's BOTEC is going to get you a similar answer in the tens of KW's power (not ERP), with assumed 100 sec integrations and 1 Hz bandwidth. The assumption that the TX antenna aperture is similar is commonly made given that unknown.

Here's some info on Parkes: "The combined system operates best between 0.8 GHz and 1.74 GHz where the beamformed noise temperature is between 45 K and 60 K, the aperture efficiency ranges from 70% to 80%".

The dish is 64M diameter.

 

And the National Geographic article you linked cites the article in the Guardian, saying "The detection was leaked to The Guardian before the research was ready for publication."

 

Maybe the aliens don't know where our cell phone bands are.

 

Christmas....that's pathetic. Did it show up in the Daily Mail too?

 

But we do. Basically you have emissions (cell, ISM, etc) in several bands from 758 to 960 MHz. Some PIM products easily skirt the edge of that upper spectrum.

If the researchers cannot distinguish between a PIM product (terrestrial) and a bona fide ET intelligent signal, then they have failed to have a search protocol that works.

 

I don't know. But it showed up in Scientific American, too. (Which incidentally also mentions The Guardian as where the story initially "leaked").

 

Yep. Its in the DAILY MAIL too...published before SciAm or any of the US ones.

Alien hunters 'carefully investigating' a mysterious radio signal from Proxima Centauri | Daily Mail Online

The least the authors could have done is publish an abstract in archiv.org ,rather than letting it break in the Guardian and Daily Mail...

 

That frequency is within the range of frequencies covered by Parkes, according to the "Parkes Users Guide".

So, what we don't know is if 980 MHz is in fact what the "leaker" told the Guardian, and that the Guardian reported it accurately; and if so, whether the scientists are sure they weren't hearing someone's cell phone. I assume they would have checked that out.

But this dust-up is why scientific papers should not be "leaked before research was ready for publication". Especially to news organizations. There are a lot of Big Fish associated with this program, as well as probably a lot of little fish. If there was a leak, it could have come from either end of that spectrum.

 

Well, hope this doesn't turn out to be someone using their iPhone to turn on their Google Nest coffee maker, or something else mundane.

"Leaks" could be a public relations disaster for future SETI work. Even in a fairly arcane (to the general public) field like I was involved in, I've seen incidents where pre-publication leaks, or even official news releases taken out of context, resulted in almost as much effort doing damage control, as the research itself took.