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vlaiv

Fast radio bursts and amateur astro community

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Just been reading latest astronomy news (as one does on a quiet Sunday afternoon :D ) and I noticed that FRBs are quite a hot topic at the moment.

That got me thinking, could amateur community get involved in some way.

Obviously direct observation is waaaay out of reach, but could there be another way? After all, we don't have a clue what might be causing them, and we don't know true "extent" of the phenomena. What if this phenomena is not restricted to radio part of spectrum, and in fact there is emission over the whole spectra? That would mean that there should be signature in visible part of spectrum as well?

Given the intensity of phenomena, I don't think it is far fetched to assume that there should be at least couple of photons, even more for very brief duration that could be picked up by amateur telescope. Maybe we already know about this phenomena and attribute it to something else?

I'm aiming here at "cosmic ray hits" that we get on our images from time to time. We consider them to be just noise and use different algorithms to remove it from our data - like sigma clip stacking. What is some of these events that we classify as cosmic ray hits in fact come from FRB type events? Since majority of FRB events are one time thing - it would not repeat on multiple frames - we would not have a reason to believe that it is anything more than a "glitch".

How would we then go about trying to detect such events? I think answer is real easy - collaboration. Comparing subs that different people took with different gear at different locations at the same time of the same region of the sky could be a way to detect this. If "cosmic ray hit" occurs on more than one instance at roughly the same time (subs are unlikely to be precisely timed, and are likely of different duration - but there is certainly going to be overlap and FRB events are very short - chance of spanning multiple subs is effectively zero) at the same place in the sky - then I would say we have a likely candidate for FRB type event.

So first stage would be to try to see if such events actually exist (and are within the reach of amateur equipment). Next would be to try to match that with detected actual FRB - as far as I can tell there is significant effort within science community to increase both detection rate of these events and also trying to get their location precisely. In couple of years I think it will be common place to have multiple events detection each day with their position known - then we can compare our data to it and see if we find any matches.

What ya all think of this?

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There was some talk of a phone app to monitor FRBs so that phones all over the World could be used simultaneously as an Earth sized array, don't know what became of the idea.

Dave

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I think just like other aspects of astronomy, what seems to be out of the reach of amateurs now, can and most likely will be proven wrong in the future... I mean amateur astronomers come out with images today that were thought impossible outside of the professional realm... quite often amateur images are better than what the pros come out with.....

Comet impacts on Jupiter were mainly spotted by amateurs in the recent past too.... so its very interesting.

 

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One way to confirm if something in an image is a hot pixel or cosmic ray strike would be to have 2 telescopes and 2 cameras pointing at the same target. Both scopes with synchronized exposures. Say constantly taking 1min exposures each aat the same cadence. If something odd appears in both images in the same ra-dec coordinates then there's a good chance its some transient event rather than noise.

If I could just get a second C11 and Atik383 I'd give it a shot 🙂

 

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1 hour ago, vlaiv said:

Given the intensity of phenomena, I don't think it is far fetched to assume that there should be at least couple of photons, even more for very brief duration that could be picked up by amateur telescope. Maybe we already know about this phenomena and attribute it to something else?

I'm aiming here at "cosmic ray hits" that we get on our images from time to time. We consider them to be just noise and use different algorithms to remove it from our data - like sigma clip stacking. What is some of these events that we classify as cosmic ray hits in fact come from FRB type events? Since majority of FRB events are one time thing - it would not repeat on multiple frames - we would not have a reason to believe that it is anything more than a "glitch".

 

The problem is cosmic ray hits are not the same as detecting " a couple of photons" though. A cosmic ray hit produces typically tens of thousands of electrons in the detector so are extremely strong signals. I think you would have a problem detecting the correlation of a weak signal between amateur images.  I have sometimes wondered though about using synchronised telescopes to do high speeed photometry, removing scintillation noise by cross correlation and detecting high speed variability brightness in targets.

Robin

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57 minutes ago, dokeeffe said:

One way to confirm if something in an image is a hot pixel or cosmic ray strike would be to have 2 telescopes and 2 cameras pointing at the same target. Both scopes with synchronized exposures. Say constantly taking 1min exposures each aat the same cadence. If something odd appears in both images in the same ra-dec coordinates then there's a good chance its some transient event rather than noise.

If I could just get a second C11 and Atik383 I'd give it a shot 🙂

 

Not sure if exact sync of subs is needed - if anything resembling a signal is detected on any two of subs - each one at different scope / location but at the same celestial coordinates and same time frame (actual time frame will be dictated by intersection of two exposures that captured it) - then we could say we have something interesting - of course multiple scopes / location would only increase confidence of genuine event.

Don't think anyone should "double" their kit just for the effort alone, but many people do image night sky and there is a chance that some of them will image same part of the sky in the roughly same time frame.

Actual effort needed would be to first come up with protocol for examining subs from a session and extracting possible candidates - this should be fairly easy - sigma clip stacking and instead of taking image result we examine rejected pixels or group of pixels appearing on only one sub at particular location. Next we create list of candidates which can consist out of just few numbers:

RA, DEC, Start time, End time, any sort of rough photometric measurement - to get rough idea of intensity.

Such data can then be submitted to repository which will do cross reference checks and produce "confirmed" events (any submitted events that are close enough in given coordinates).

Of course this would need software support, but for start it can be simple two or few party collaboration - much like people do with imaging - they agree to do collaboration on target to produce an image. Only difference here being that end result is not image (although it can be) - but search for fast transient feature, and that it needs to be at same time interval (not so with imaging).

1 hour ago, robin_astro said:

The problem is cosmic ray hits are not the same as detecting " a couple of photons" though. A cosmic ray hit produces typically tens of thousands of electrons in the detector so are extremely strong signals. I think you would have a problem detecting the correlation of a weak signal between amateur images.  I have sometimes wondered though about using synchronised telescopes to do high speeed photometry, removing scintillation noise by cross correlation and detecting high speed variability brightness in targets.

Robin

Indeed, we have no idea if phenomena will be detectable in visible part of spectrum - either because it does not produce radiation in that part of spectrum, or maybe radiation is too small to be detected (either by size of instruments, or even in principle due to distances involved and attenuation in interstellar / intergalactic medium).

We could do rough calculations though - if we get total power registered by certain telescope - and as far as I read, it is quite strong - comparable to total solar energy output in a single day. We could do simple (and I'm certain wrong) assumption that it follows black body radiation to figure out how much energy there would be in 400-700nm range given power in radio domain and scale that to "sensible" aperture - like 100-200mm and convert to photon count. If we get anything "detectable" - meaning at least 5-10 photons or more per event - then it would make sense to try.

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There are a lot of deep optical surveys looking for transients already running.  If there are bright fast optical transients around it would be surprising if someone had not picked up on these already.  Provided images are not undersampled, I dont really see cosmic ray hits producing false positives for fast optical transients.  Optical transients and cosmic ray hits etc are easily distinguished from their PSF so you don't need synchronised telescopes to distinguish them, just a second follow up image.  An independent corroborating image showing the transient would be useful to convince sceptics that the detection is real of course but a first step could be to check some existing sub images looking for potential transients which are not cosmic ray hits to see how many candidates there might be. 

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On 07/07/2019 at 16:07, dokeeffe said:

One way to confirm if something in an image is a hot pixel or cosmic ray strike would be to have 2 telescopes and 2 cameras pointing at the same target. Both scopes with synchronized exposures. Say constantly taking 1min exposures each aat the same cadence. If something odd appears in both images in the same ra-dec coordinates then there's a good chance its some transient event rather than noise.

If I could just get a second C11 and Atik383 I'd give it a shot 🙂

 

That has to qualify as one of the best excuses for buying additional gear I have ever encountered. Wonder how many of us would get it past the "expenditure officer" ...

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12 hours ago, Demonperformer said:

That has to qualify as one of the best excuses for buying additional gear I have ever encountered. Wonder how many of us would get it past the "expenditure officer" ...

FNB's = Fast No Bursts 😉  

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