My unsupported hypothesis: Gamma radiation from the blast was reaching the film that was being used to take the astronomical observations.
For this to work, though, a few things would have to be true:
1. The film would have to be stored in bulk in a place that would be (mostly) protected from gamma rays from the tests.
2. The film for that night's observations would have to already be not with the rest of the film at the time of the test.
3. The observatory would have to be close enough to the location of the test that the gamma rays would have a chance to reach it.
But maybe it doesn't have to be direct. Maybe it could be gamma rays produced by the fallout, which drifts from the location of the test to at or near the observatory.
Then you have to wonder why no more were observed after March 17, 1956. A change in the character of the film? (Either a change in manufacturing process, or a change in what kind of film was used?)
https://www.orau.org/health-physics-museum/collection/nuclea...
Kodak had this issue for sure.
It's also just a permanent issue for sensitive instruments for scientific experiments. The Cold War bomb testing spree contaminated so much there's a whole demand for metals produced before the first atomic test because of the increased presence of fallout from the tests.
The issue is relegated to only the most sensitive equipment these days but it's a funny little side issue for several years before the test ban had been in place long enough to reduce the elevated levels back to nearly background.
That wouldn't explain why the effect only disappears for parts of the sky within Earth's shadow.
Dots doesn't disappear from Earth's shadow, there are just little bit less of them statistically. And she can't explain that in her paper at all, if those are supposedly objects and not plate defects, then why are they in a place, where objects shouldn't appear.
Also, assuming her hypothesis is correct and she didn't made factual mistakes - to be presented as dots and not streaks, all of these thousands of objects should be in a tiny narrow band in GEO spread out all across the orbit envelope. Where did they disappear in between 50 minutes from red plate to blue plate? And then this somehow repeated every single time in that particular order? An alien armada sitting precisely in a single orbit and then vanishes on a cue from a some lone observatory on Earth, when technician changes plates there? Then again appears all strictly in GEO, then again disappears in 50 minutes after?
Doesn't it look absurd to you?
> "We also find a highly significant (∼22σ) deficit of POSS-I transients within Earth's shadow when compared with the theoretical hemispheric shadow coverage at 42,164 km altitude."
I'm not an statisastroscienticianist, so I have no idea what that means, but maybe it's significant.
That being said, Kodak discovered nuclear testing was a thing before the public for all the obvious reasons.
The problem with that impressive 100500σ figure, is that she refuses to provide code which she supposedly used to supposedly prove that Earth shadow has some influence on these dots on the images made from photo plates. I.e. this 22σ figure is a "pinky promise" level "science".
The earths shadow effect lowered the transients by about 33%, which does provide evidence for physical reflection accounting for 1/3rd of the effect. To my mind, gamma ray-like exposure on the film is an extremely plausible explanation for the other 66%.
It occurs to me that the gamma ray hypothesis has a fairly easy check. Light sources pass through the telescope’s optics (typically mirrors or occasionally lenses) which leads to a characteristic “point spread function” for point sources like stars. If it were an errant gamma ray exposure directly on the film, it’s extremely unlikely to have the PSF of the standard light sources.
You can compute the PSF from known stars on the same image and run a statistical test, but TBH just visually comparing the transient with a few stars of similar brightness on the same image should put this one to rest.
Following up on this, I eyeballed the images in this one: https://iopscience.iop.org/article/10.1088/1538-3873/ae0afe
The brightest stars in all of the images have a clear 4-pointed pattern. The brightest transients _do not_ show this pattern.
This is obviously not definitive, and the fainter stars are harder to eyeball the PSF, but it does provide some evidence to support the hypothesis that the brighter transients could be due to gamma ray exposure of the film rather than flashes in the atmosphere or space.