A new field of astrophotography?

[Richard N]

Someone from our club was shooting darks and recorded a transient bright streak. He has speculated that it was caused by a high energy cosmic ray. Might that be the case? And if so does this open up a new sort of astrophotography?

[vlaiv]

I think that 99.9% of "cosmic" rays that we capture during recording of darks are in fact terrestrial in origin.

I once recorded set of darks near wood burning stove that was not clean (it was winter time and it has been fired up day before).

I had massive amount of streaks. It appears that ash has heightened levels of radioactivity. Nothing to cause concern otherwise - but shows up in darks readily.

[Richard N]

As far as I can tell this was a dark done in the day with the sensor covered. 

[symmetal]

Here are the results of a couple of detailed studies into radioactivity in wood, and its affect on CMOS sensors.

Radiological impact of using forest tree biomass for energy and recycling the ash

Using CMOS Sensors in a Cellphone for Gamma Detection and Classification

Alan

Edited December 20, 2023 by symmetal

[tomato]

I get little streaks and hot pixels appearing regularly on my all sky camera frames, and a neighbour about 150 metres away has a wood burning stove that he runs a lot during the cold months. Are they related I wonder, I always thought they were cosmic rays hitting the sensor. 

[Ags]

How can this be? Surely the ash I scrape out of my fireplace is exactly as radioactive and the wood I feed into it? My fireplace seems to work on the basis of chemical combustion, not nuclear fusion. But perhaps I am doing it wrong?

[symmetal]

In air a gamma ray from radioactive decay can travel tens to hundreds of feet depending on its initial energy according to this article. The primary source of gamma radiation in wood is indirectly from Caesium-137, having a photon energy of 0.6617MeV. Not sure how to convert this into air distance. 🤔

From Wikipedia, Caesium-137 decays by beta emmision into an unstable form of Barium-137, which quickly decays into a stable state emitting the gamma rays in question.

So your neighbour may be causing your pixel streaks. 🙂

Alan

Edited December 21, 2023 by symmetal

[Ags]

I am intrigued. I am going to try photograph my ash with ASI485MC. I will collect several loads of ash and take a couple of 10-minute subs next to the ash and away from the ash. 

[symmetal]

48 minutes ago, Ags said:

How can this be? Surely the ash I scrape out of my fireplace is exactly as radioactive and the wood I feed into it? My fireplace seems to work on the basis of chemical combustion, not nuclear fusion. But perhaps I am doing it wrong?

Many radioactive elements exist naturally and their decay products are absorbed by living organisms. Caesium-137 (UK spelling) is a problem as it's water soluble and readily taken up by plants. Its primary souce in the environment in recent times is in the fallout of nuclear weapons, and nuclear power accidents like Chernobyl. It has a half life of 30 years so fallout from Chernobyl is the main source currently, though older internal tree rings will have nuclear testing Cs-137 present. Scandanavia was significantly affected by Chernobyl, so wood burned from there will end up having ash with a higher concentration of Cs-137 than wood from other areas. The burning itself doesn't change the quantity of Cs-137 present.

Cornwall has large amounts of granite which contains Uranium-238 naturally, and a trace decay product is Cs-137, among others, and so we have one of the highest background levels of radiation in the country. Radioactive radon gas is a concern here too which is a decay product of Radium-226, a decay product of Uranium-238. So beware your granite worktops. 😊

Alan

Edited December 21, 2023 by symmetal

[vlaiv]

10 hours ago, Ags said:

I am intrigued. I am going to try photograph my ash with ASI485MC. I will collect several loads of ash and take a couple of 10-minute subs next to the ash and away from the ash. 

Use standard deviation stacking to expose the streaks.

[Tomatobro]

We have been using smokeless so I guess the ash is pre bomb testing but have put the wood burning plate in so I can do a test when we next have a fire. I will take darks  close to and far away from the fire to see if there is a difference. 

[tomato]

Radon gas is no joke, it nearly scuppered my daughter’s first house purchase.

[callump]

Here's an article about capturing cosmic rays with a DSLR:

https://britastro.org/2023/capturing-cosmic-rays-with-a-digital-camera

Callum

[Astronomist]

I left my DSLR recording a 600 minute exposure next to a woodburning stove with ash in it, not sure if the proximity of the woodburner made any difference at all to the results though.  Got some promising looking streaks:

I found it easier to spot the streaks in B&W, hence the lack of colour. do you reckon this really is a gamma ray / muon streak, or just conveniently placed noise?

Edited December 21, 2023 by Astronomist

[vlaiv]

3 hours ago, Astronomist said:

do you reckon this really is a gamma ray / muon streak, or just conveniently placed noise?

That looks like legit hit, but we can't really tell what the source of it is.

If you were inside of the house - it is most likely local in nature, but again, some high energy particles can go thru solid walls with ease.

[Adam J]

On 20/12/2023 at 18:28, vlaiv said:

I think that 99.9% of "cosmic" rays that we capture during recording of darks are in fact terrestrial in origin.

I once recorded set of darks near wood burning stove that was not clean (it was winter time and it has been fired up day before).

I had massive amount of streaks. It appears that ash has heightened levels of radioactivity. Nothing to cause concern otherwise - but shows up in darks readily.

Well so long as the wood was not sourced from the Red forest then your fine. 

[ONIKKINEN]

I took 27x 3600s darks a year ago to see how many "hits" the sensor got and stacked with maximum, stretched result below:

There are a number of streaks in the image, whether cosmic or local in nature is not something i know the answer to, but could be that some of them are cosmic rays while most likely local radiation hits. Taken indoors in an apartment building, so thick concrete walls all around.

[Bugdozer]

Speaking from my experience of working with radiation for 19 years as a radiographer, and having studied it at degree level, with individual sporadic captures of this kind, it's virtually impossible to determine the source. It could be a cosmic ray, it could be radon in the air, it could be a single atom of a radioactive substance stuck to your shoe that just happened to decay at the right time. Radioactivity and ionising radiation are everywhere to a greater extent than most people realise. 

Regarding ash versus wood: per unit of mass, ash is more radioctive due to the higher carbon concentration (carbon occurs more commonly as a radioactive isotope than hydrogen does). However, the amount of activity from ash cannot exceed that which was present in the wood initially, as long as the absorbtive properties of the wood are discounted. 

Try leaving a banana next to the camera. They are generally more radioactive than their surroundings due to the high potassium content. 

[ONIKKINEN]

48 minutes ago, Bugdozer said:

Try leaving a banana next to the camera. They are generally more radioactive than their surroundings due to the high potassium content. 

So how about a test then? Take some darks with a bunch of bananas next to the camera and see if there are more hits?
Forecast is cloud and more cloud for the foreseeable future so i might just try that over the holidays, and i already have the control image to compare to.

Mushrooms are another option, they are still radioactive from Chernobyl fallout here in Finland. Occasionally some are tested to be slightly above the EU suggested limit for Cesium-137.

[symmetal]

A useful article which put things into perspective: Is it true that bananas are radioactive 🙂

Alan

[900SL]

I have a wood burning fire here in Finland and I keep an ash bucket by the fireplace.

I must thank the posters in this thread as I was wondering why I had grown two heads and my spiders were the size of sumo wrestlers. I'll keep it outside from now

[Ags]

I decided my ash-stash might have reached critical mass, and inspired by watching Oppenheimer, I decided to try capture some death rays tonight. I shot darks as usual, and then a sequence of 8 one-minute subs of no-ash and 8-minute subs with the camera sitting on a cushion of ash. Then I stacked in DSS (no alignment, using Maximum as the stacking algorithm). I think i may have some camera or stacking settings wrong as the hot pixels came out as a characteristic pattern of six pixels...? But, the with-ash stack picked up a definite radiation trail!

There were no trails in the no-ash stack. I don't think a single trail is proof my ash is the radiation source of course. I will collect more ash and do a longer stack, maybe 20 minutes. In the meantime while I hoard the ash I will try figure out why my hot pixels look funny.

[Mr H in Yorkshire]

If you want to check that you really are picking up radiation effects you might try sitting your camera on a block of granite.

[Ags]

Because granite is naturally radioactive? Not sure I have a lump of granite, but will try the experiment when I can.

There is a village in Iran that is off-the-scale naturally radioactive. I have no plans to travel there to find out however 😀

[vlaiv]

11 hours ago, Ags said:

I will try figure out why my hot pixels look funny.

Is that a single sub or stack, and if it's a stack - what type of stacking did you use?

CMOS sensors have this very interesting noise pattern that is not obvious at first glance.

It is type of random electron leak which happens on junction between pixels and sometimes leaks into one pixel and sometimes into adjacent one. When you examine subs in sequence - it looks like these pixels are blinking and this type of noise is often named telegraph type noise because of this.

If you however use stacking and use standard deviation as stacking method - these pixels will lit up because there is much higher uncertainty in their value / larger standard deviation spread because of this telegraph type behavior. They are like hot pixels - but randomly hot and not always.

On my ASI1600, I get them in very distinct way - always a group of 2 pixels and always in diagonal direction:

This is standard deviation stack of 64 one minute darks (random crop from a part of sensor).

Here is animation to get the idea why it's called telegraph type noise: