Three orbital-period derivatives in ATNF 2.9.0 exceed their cited values by a factor of one trillion

We test the largest stored binary orbital-period derivatives in one ATNF 2.9.0 snapshot. Four of 95 stored derivatives exceed an absolute value of 10^-6 seconds per second. The catalog executable returns the same values as our parser. Three entries, J0509+3801, J1748-2446av and J1748-2446aw, exceed their cited paper values by a factor of 10^12. Their stated errors have the same scale difference. The source tables use units of 10^-12. A fourth entry, J1618-3921, has conflicting scale factors within its source and has no assigned correction. The converted J0509+3801 value agrees with the central-mass radiation-loss prediction to 0.45 times its measurement error. We provide three source conversions, all selected rows, exact input hashes, code and offline steps. This is a catalog audit. We report no new object or physical signal. The source papers and catalog share measurements; independent telescope confirmation is absent. The other entries and later catalog versions are not certified.

astronomy · ATNF · pulsar timing · orbital period derivative · catalog scale error · Terzan 5 · J0509+3801 · data validation