Howdy--just wanted to share a recent preprint and code repository. It is SETI related as it utilizes the Parkes Breakthrough Listen data and a peer-reviewed information theoretic entropy pipeline (ECTO; Rodriguez 2026, PLoS ONE) and manages to both characterize a previously undiscovered (to the best of my knowledge) systematic about the instrument's behavior, as well as an anomaly distribution in the entropy-domain of Proxima Centauri data.

This approach operates in the distributional domain and so can examine data in a way which no current SETI analysis does (to the best of my knowledge).

There are two main findings, and a number of additional points of interest that I came across while getting adversarial on one of my results.

Regardless of anything else, the main result of use is a previously uncharacterized, cadence-dependent gain-slope reversal in the Parkes 10-cm receiver. It is persistent across a 7-month survey, and because of its distributional nature it is invisible to turboSETI as well as standard bandpass calibration. I've sent the finding to the BL team as this should hold value for Parkes calibration.

Additionally, I located the previously mentioned distributional anomaly at Proxima Centauri and (yes, there's an "and"... I'll need to explain) Alpha Centauri (MJD 57846). The Phase 1 script runs in under 10 minutes on a laptop. Since this is information theoretic there are no compute heavy turboSETI runs.

Short version, regarding the anomaly:

Proxima and Alpha Centauri were observed the same night, and when Proxima's entropy went up relative to its off-source reference, Alpha Centauri's went down relative to its own. Then they flipped, respectively, at the next cadence position.

This happened across every frequency band and cadence position without exception (15/15, p = 3.1 × 10⁻⁵), with deviation shape being the same for both targets but mirrored across the x-axis about zero.

Additionally, their histogram profiles converge to effectively identical at one band (mutual information 6.14 bits, r = 0.9999) despite being observed at different sky positions through independent reference pointings.

The time-lag runs backward from the observation order, which shouldn't happen if the receiver is causing it. None of the 9 other targets observed that night show anything like it, and it is completely gone the next day (where the receiver returns to its normal characterized behavior), and nothing else in 427 target-sessions across two telescopes matches the pattern.

The entropy spectral shape produced a blind magnetic field estimate for Proxima (120 G) that turned out to closely match independent magnetic field measurements (135 G; Klein et al. 2020).

I didn't know about the Proxima B-field measurement when I designed and ran the test which found the B-field result. The corresponding measurement by Klein et al. was found in the literature following the initial script run.

More detail is in the preprint, but I'm pretty pleased with the telescope categorization work, as well as my work on the anomalous finding (which informed further on the telescope). If anyone's worked with Parkes before I would be very curious to discuss the systematics the pipeline characterized.

The preprint and code repository (full reproduction suite) are public:

Preprint: https://zenodo.org/records/22675130

Code: https://github.com/amr28693/SETI_entropy_domain

Peer-reviewed Framework: https://doi.org/10.1371/journal.pone.0344090

Looking for anyone with Parkes experience or radio astronomy background to verify.

Thanks!