Transients in the Palomar Observatory Sky Survey

[John J.]

has Villarroel indicated at any point that they have reached out to the "custodians of the plates" to ask for access and if so have they reported the response?

I don't know. Maybe others do, but I don't remember Beatrix Villarroel suggesting this (which doesn't mean she hasn't).

I guess many other astronomers have done work based on/ informed by DSS and/or SSS, and probably the earlier glass POSS1 copies (perhaps more so pre-digitisation). If this is the case, it might be argued that those astronomers were not obliged to refer back to the original material (conjecture, maybe some were, I don't know). But I feel B.V. et al.'s transient papers are perhaps different; their findings are extraordinary and if accepted their implications are far-reaching. Hambly and Blair have raised what might be plausible concerns about reprographic artefacts, which might be tested by examining the POSS1 plates. Maybe other relevant insights would be made while examining the originals.

I don't know anything about access to the POSS1 plates. Even if allowed, a re-examination of the 1st generation plates (presumably "in situ") might be a much more time-consuming, inconvenient and in effect expensive process than the study of the digitised material.

 

[jon_eir]

I don't think they have actually examined the original plates. However I think they would say they have shown that the transients can't be emulsion artifacts because their distribution has been shown to correlate with the Earth's shadow. But even that logic has been shown to have some questionable assumptions and tenuous rationale.

Snips from my post #72:

To me having not looked at these papers in 2 years nothing seems to have moved on. Like you said all the assumptions made around why these may not be plate artifacts seem flawed either,

1-address the issues the authors themselves highlighted in the 2021 paper
or
2-clearly state the problem or the assumptions being made on those issues in future papers

Completely pointless discussing/building on the initial work without this. Go make some plates again and do a study on that even to further the conversation.

 

[AmberRobot]

I don't know. Maybe others do, but I don't remember Beatrix Villarroel suggesting this (which doesn't mean she hasn't).

to me, it seems a major oversight to not examine the originals, and if she had tried and was rejected that would be an important point to make in order to show that one is trying in good faith to rule out an instrumental artifact. It seemed like she just said "I don't have access to the originals" and then carried on leaving the uncertainty just hanging over the entire work.

 

[jdog]

to me, it seems a major oversight to not examine the originals, and if she had tried and was rejected that would be an important point to make in order to show that one is trying in good faith to rule out an instrumental artifact. It seemed like she just said "I don't have access to the originals" and then carried on leaving the uncertainty just hanging over the entire work.

Properly assessing the original plates -- especially dealing with any significant number of suspected transients -- would have to be done by someone with expertise in glass-plate astrophotography. Probably someone working at the one of the several astronomical archives holding glass plate collections, like Harvard College Observatory or the Carnegie Plate Archives.

 

[AmberRobot]

Properly assessing the original plates -- especially dealing with any significant number of suspected transients -- would have to be done by someone with expertise in glass-plate astrophotography. Probably someone working at the one of the several astronomical archives holding glass plate collections, like Harvard College Observatory or the Carnegie Plate Archives.

And that could in principle be done in collaboration with Villarroel but there's no indication that I have seen that this was attempted.

 

[NorCal Dave]

Properly assessing the original plates -- especially dealing with any significant number of suspected transients -- would have to be done by someone with expertise in glass-plate astrophotography. Probably someone working at the one of the several astronomical archives holding glass plate collections, like Harvard College Observatory or the Carnegie Plate Archives.

And may have been a bit of a wild goose chase before. But her most recent paper has identified 203 transients on plate(s) from 1 particular day, 5/3/1954:

To maximize likelihood of interpretable results, we again focused on the highest probability transients (≥ 0.90 probability of being a real transient per the ML model) [10].There were 231 transients meeting this criterion observed within +/- 1 day of a nuclear test(for nuclear testing details, see https://nnss.gov/wp-content/uploads/2023/08/DOE_NV209_Rev16.pdf). Of these, 203 transients (87.9%) were associated with a single nuclear test:Castle Yankee conducted on 5/4/54.

In addition, these transients are supposedly located in particular spots over the Eastern Pacific, off the coast of Mexico:

Cluster 1 was centered in the Pacific ocean to the southwest of Baja California. Clusters 5 and 6, while statistically distinct, were located in two adjacent regions of the Pacific further south than Cluster 1, with both being to the west of southern Mexico and Central America. These two clusters combined represented the location of nearly 65% of all high probability transients identified.

https://arxiv.org/pdf/2609.09461

So, there is a plate(s) from a particular day that has 203 transients in a particular area on it. That would substantially narrow down what to look for on the specific original plate(s). As there is a specific plate(s), it should also be easier to track the copy(s) from original to digitization thus providing a complete pipeline that can be checked for transients. Right?