180 Degrees of 24 Years

Astronomy

I think I have just seen a fast radio burst. It wasn’t there a moment before. A first magnitude star, between Canopus and the LMC, it could have been delta-Dorado but it was bright, as bright as Sirius, -1.5 at least, and not in motion as a flaring satellite would, but fixed, like a star flaring up and then fading.

I didn’t know what it was, I glanced up-right toards Achernar to get my bearings and back again only to see it fading quickly, in a second or two it had gone. I was quite surprised, even disoriented by this and wondered absurdly if Canopus had gone behind a cloud, even though Canopus was still there near to the left and there was no cloud but Magellan’s.

I stared at the spot for long seconds, seeing delta-Dorado more or less where it had been, but nothing else. I racked my brains for a coherent idea about suddenly seeing something flare; like a supernova, but I know they last days, not seconds. What had I just seen? Not in motion, fixed, white, star-bright.

I stood there for a good five minutes, staring at the same spot, wondering if I’d been looking at Canopus after all, but the spot I had been looking at was there in Dorado and I had a vivid image of it in my mind: it had faded from nearly the first instant of my seeing it. I had not seen it brighten but must have noticed it immediately as I was looking roughly in that direction. There it was, then immediately fading. I could still see it happening every time I thought of this. I grew more amazed, stood there measuring its position near enough with my hands, but had to admit I could fix no better position than that it was “near d-Dorado”.

I went inside, told my wife, googled “supernova Dorado” and wasted some minutes in which I forgot to note anywhere near the exact time of the event. Aghast, I looked at the clock and worked backwards roughly twenty minutes to 10:30 PM. No better than 2 degree and half hour accuracy, damn, damn.

How do I find out if there’s been a supernova in Dorado? A… what, a fast supernova?

I had never heard of fast radio bursts, or FRB’s. I’m an amateur astronomer, and they’re pretty new. FRB’s are a type of deep sky object, discovered only in 2007, and usually detectable only by their distinctive radio signal, a descending tone through a wide range of frequencies. The actual radio burst is theorised to be only a few milliseconds long, but the distances are so enormous that the time dilation brings that down to the kind of sound a human could produce, a short, 1 – 2 second down-whistle: https://astronomynow.com/2016/11/15/fast-radio-bursts-born-in-cosmic-cataclysms/

I saw that sound! That is exactly the impression of what I saw, a rapid, 1 – 2 second descent into dimness. Bright, white, star-like, fading like that descending tone. No change in colour, just white becoming faint, then nothing.

I have just done this burst of research to try to decide if I am insane, and written this blog post to confirm my observation with a date-time stamp. I find there’s a reference naming system for these things, of which only about 2000 have been discovered. They’re named FRB YYMMDD so that was FRB 161124 at 10:30PM I saw in Dorado, RA:Dec 66o:5h40m. They are apparently very frequent and are being detected more often now as we learn to find them. We have measured the distances but have never seen any visual counterpart of the radio signal.

Yesterday now as it’s gone midnight, I may have seen the first visible evidence of an FRB. I know how to look this up and find out. I have its name. If no one’s on the job in CSIRO tonight, I have probably been the first to give the event its name.

https://www.obspm.fr/spip.php?page=imprimer&id_article=2998&lang=fr
https://www.ras.org.uk/news-and-press/2578-cosmic-radio-burst-caught-red-handed
http://www.csiro.au/en/News/News-releases/2016/Solved-First-distance-to-a-fast-radio-burst

Next day, I contacted Simon Johnston head of Astrophysics in CSIRO:

Dear Simon,

Would you be able to confirm an observation of a fast radio burst at RA:Dec -65o40′:5h40m at about 10:30 PM last night, 24/11/16 AEST?
I am able to describe its visual appearance, if it actually occurred.

Regards, Dr Mike Evans
> University of New England
> Physics and Electronics

Hi Mike,

The Parkes telescope wasn’t looking for FRBs last night unfortunately.
In any case our field of view is very small (about 1/2 a square degree
on the sky) so the chances that we would be pointing in any given
directions are very small.

Was what you saw atmospheric? Some sort of meteor? Or was it just
a brief flash of light?
Cheers Simon

 

I don’t know that there’s much more I can do. There’s a catalogue of FRB’s but I’m not sure if it’s being updated. I can ask around science agencies worldwide if anyone picked up an FRB that night, but I don’t know. That thing was too bright to be in another galaxy, but if it was relatively nearby it doesn’t explain the time dilation. David Lamb suggested it might have been a meteorite coming straight towards me, but I’ve seen those things at intermediate sizes and they flare fiery colours. This was not atmospheric.

…It was a white star-like object that was not there a moment before, then a rapid fade to nothing over no more than 2 seconds. Did not appear atmospheric, it was radiant white. There was no change in visual appearance, no colour change or bursts, just a smooth fade of white star light…

So I suppose I’ll be wondering about this for the rest of my life.

 

 

 

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