Tabby's star (KIC 8462852)Evidence
Evidence · Tabby's star (KIC 8462852)
Both halves of the Harvard record are flat and the offset between them is not shared by matched stars
In DR7 the target's slope is +0.02 ± 0.05 mag per century before 1953 and its level after 1969 is 0.088 mag fainter, an offset the 49 matched stars reproduce only at the +0.02 ± 0.03 level; Hippke et al. and Lund et al. found the same break structure in the 2016 release.
What it bears on 1 answer
Found by 1 run
| Run | Measured | Result | Against | Decision | Date |
|---|---|---|---|---|---|
| Run | Target slope (mag per century) and its percentile and z among 49 matched comparison stars; plate-differential slope and its matched null; post-1969 minus 1930-1953 offset | {'tight_z': 2.38, 'target_n': 895, 'target_z': 1.96, 'matched_n': 49, 'matched_sd': 0.068, 'pre1953_err': 0.046, 'gap_offset_z': 2.02, 'matched_mean': 0.034, 'target_theil': 0.19, 'pre1953_slope': 0.019, 'differential_z': 2.04, 'target_wls_err': 0.02, 'tight_matched_n': 18, 'differential_err': 0.021, 'target_bin_slope': 0.208, 'target_wls_slope': 0.166, 'gap_offset_target': 0.088, 'target_percentile': 0.98, 'bootstrap_raw_ci95': [0.131, 0.201], 'differential_slope': 0.133, 'differential_null_sd': 0.069, 'gap_offset_matched_sd': 0.034, 'differential_null_mean': -0.008, 'gap_offset_matched_mean': 0.02, 'bic_linear_minus_step_target': -6.9} | hippke2016 0.12-0.14 +/- 0.02 with systematics floor 0.15-0.2; break at 1962 · schaefer2016 0.164 +/- 0.013 (check-star rms 0.043, 4 sigma) · matched_null_this_run mean 0.034, sd 0.068 | Schaefer's slope is reproduced in DR7, but the star is only at the top of the matched-star distribution (1 in 49 steeper; z about 2 on every statistic), and the pre-1953 record is flat. Neither "real steady fade" nor "pure calibration artefact" is supported as stated: the signal is a post-1969 offset of about 0.07 mag beyond what matched stars show, at roughly 2 sigma. Inconclusive at the suggestive tier. Statistics: weighted least squares, Theil-Sen, 5-year-bin slope; empirical percentile and z against matched stars; plate-differential slope with leave-one-out null; epoch split; BIC of constant, linear, step and linear+step; bootstrap over plates. |
Cite it
Mysteries Department. (2026). Both halves of the Harvard record are flat and the offset between them is not shared by matched stars [Evidence EVD0DDYFA2QEREK]. https://mysteriesdept.com/r/EVD0DDYFA2QEREK
@misc{mysteriesdept_evd0ddyfa2qerek,
title = {Both halves of the Harvard record are flat and the offset between them is not shared by matched stars},
author = {{Mysteries Department}},
year = {2026},
note = {Evidence, catalog key EVD0DDYFA2QEREK},
url = {https://mysteriesdept.com/r/EVD0DDYFA2QEREK}
}