Hi
Im a casual member of the UK Radio Astronomy Association (UKRAA). The sub group I’m tagged to is the group observing muons. I havent bought an observatory yet as I’m still unsure about setting up an observatory. However, one thing that does interest me is observing muons and events from colibri to see if they are related. If i could somehow use an observatory and tie in results from colibri, then it would make observing far more interesting. Anyone got any thoughts
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Hi Lawrence!
Welcome to the forum! Thank you for this very interesting question!
In my opinion a correlation between a muon measurement and an astrophyscial transient reported via Astro-COLIBRI will be difficult to achieve. As you certainly know, the muons one detects at ground level are created within extensive air showers that are initiated by charged cosmic rays (mainly protons). Being charged particles, these cosmic rays are deflected by the various magnetic fields on their way from their source to Earth. These deflections are inducing significant time delays easily reaching hundreds and thousands of years (depending on the energy of cosmic rays).
The transient phenomena reported in Astro-COLIBRI (e.g. a supernova, a gamma-ray burst, etc.) are exlusively detected thanks to the neutral messengers emitted during the explosion.This is mainly electromagnetic radiation (i.e. photons), but can also be a high-energy neutrino or a gravitational wave. These messengers travel at the speed of light and in straight lines. If the explosion also emitted cosmic rays, they would travel a much longer path due to the magnetic deflections and would thus arrive much, much later. I believe herefore that it is impossible to correlate muons with transient phenomena.
Side note: there is a small possiblity that one could be able to see such a correlation using cosmic rays at very highest energies because they are harder to deflect which reduces the time lag. But to do so you would need an observatory the surpasses the size of the Pierre Auger Observatory with its 3000 km^2, and I don’t think you’ll that in your backyard 
Hi Fabian
Thank you for your reply. Its a shame i can’t get the PAO in my back yard as it would make for some interesting observations. As it is, currently I’ll have to rely on this platform. On a aide note, if you or any of your colleagues hear of any open workshops in the uk that would cover citizen science in time domain multi messenger astronomical physics, please do not hesitate to contact me. Also, would it be possible for the platform to consider publishing a reading list for participants of citizen science covering the various field of time domain multi messenger astronomy
Workshops: we’ll announce upcoming workshop here on the forum. One of them is our very own: it will be taking place in Paris-Saclay (France) but an online connection is possible during the first two days. Details: Announcing the 4th Astro-COLIBRI Workshop – October 20-24, 2025
Reading list: Very good idea. We’ll have a look into this, but input from the community would be very welcome for this.
Hello, I am the founder of the French Amateur Muon Network (FAMN in English but it is called RMFA in French so I will say RMFA rather than FAMN).
I have been working on a large-scale ray detection project for a year now. The project has not yet officially started but several prototypes have been built and put online. Many people underestimate the monitoring of muons but I can assure you that there is a huge amount of detection to be done.
Most anomalies in the muon flux are most often caused by the sun but it very rarely happens that detections are caused by phenomena outside our solar system. For example, several reports have been made reporting the detection of cosmic ray bursts correlated with a gamma ray burst (PARAC info --------- http://www.parac.eu/Augusto_2015_ApJ_805_69.pdf).
As Fabian Schussler said, cosmic rays are deflected by magnetic fields, but it’s not just cosmic rays that create muons; there are also high-energy gamma rays.
My goal with the RMFA is to detect solar phenomena like :
the Forbush effect, which I’ve successfully detected several times,
GLEs (quite complicated to detect with muons).
I’d also like to visualize the progress of a solar storm and its direction in space by pointing the detectors in several directions.
solar cycle monitoring
I’d also like to detect a CRE (Cosmic Ray Ensemble) with this detector array ([2112.11421] Simulations of Cosmic Ray Ensembles originated nearby the Sun).
I saw your Muon meeting on your YouTube channel and I hesitated to contact you about teaming up, so I’m doing it now. If you want more information, I have a beta version of the website: http://91.168.247.111:32880/
Sincerely, Gabriel
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Thanks a lot for these informations and the discussion! Its great to see these cross-border contacts being established.
I was not aware of the papers you mentioned and will have a closer look. Solar events (and the induced muons) are certainly an interesting field of study that I had ignored in my post that was very much biased towards (very) high-energy and extragalactic sources.
Thanks again!
Thank you for your reply! Meeting people and sharing a bit of knowledge is exactly what I was hoping for when I came to this forum 
. I’m really happy to have been able to change your perspective on muons. Muons are a truly fascinating research topic, but unfortunately, they’re not yet widespread enough. My goal would be to have, on the one hand, a large, professional-quality detector, and on the other, a vast network of small detectors whose data would be usable, in order to expand the detection possibilities. I would love for you to take part in our project, particularly to enable the observation of multi-messenger phenomena. If you’re interested, would you be willing to organize a meeting at your convenience?
Sincerely, Gabriel 
Muons are certainly key players in high-energy astrophysics!
I’ll reach out to discuss this further — I’m still not entirely convinced about the effectiveness of using muons to detect and distinguish gamma-ray–induced air showers from those triggered by hadronic cosmic rays. 
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