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MethodsAstronomy: time-series photometrySingle-event dip search with injection-recovery and fair nulls
Method · astronomy: time-series photometry

Single-event dip search with injection-recovery and fair nulls

Test whether HD 139139's 2017 dips recur in later photometry, and whether dips like them are common in other bright K2 stars.

Astronomy: time-series photometryVersion 1.0Licence MIT3 runsUsed on 1 mystery

Questions it answers

Code Python

Download module (.py)dips.pyView source

Runs and results 3 runs

RunMysteryMeasuredResultAgainstDate
RUN0DD2GVJ41GHKHDDips vs sign-flipped bumps at >=5.5 sigma; published dips recovered{'EVEREST': [19, 4], 'K2SFF_all': [23, 12], 'K2SFF_ge1.5h': [21, 6], 'recovered_K2SFF': 22, 'recovered_EVEREST': 17}Sign-flipped search with symmetric outlier handling
RUN0DD2GVRRESBSHDPer-dip completeness and expected detections at the K2 rate (>=4.5 sigma); detections in real data{'candidate': {'btjd': 3778.5485, 'depth_ppm': 507, 'duration_h': 2.24, 'depth_err_ppm': 105}, 'expected_A': 0.44, 'expected_B': 0.7, 'completeness_A': 0.094, 'completeness_B': 0.149, 'fap_independent': '0.5-2%', 'real_detections': 1}Noise-only false alarms at >=4.5 sigma: 0.014 per 13.5 d (circular-shift null) · independent check with white and phase-randomised nulls gives FAP 0.6-1.6% for the candidate
RUN0DD2GW3R2EAJHDExcess = dips - sign-flipped bumps at >=5.5 sigma, events >=1.5 h, K2SFF{'rank': 5, 'n_stars': 619, 'HD139139': 15, 'population_quantiles_50_90_99': [0, 1, 9.6]}The same statistic across 619 stars of Tmag 8.6-9.7 in C15

Applied to

HD 139139, the "Random Transiter"
3 datasetsK2 Campaign 15 light curves of EPIC 249706694 (pipeline, K2SFF and EVEREST), TESS Sector 91 full-frame-image light curves at the position of HD 139139 (2025), Table of the 28 transit-like events (times, durations, depths)

References

  1. Rappaport, S., Vanderburg, A., Kristiansen, M. et al. 2019. The Random Transiter – EPIC 249706694/HD 139139. Monthly Notices of the Royal Astronomical Society 488(2), 2455–2465.
  2. Alonso, R., Hoyer, S., Deleuil, M. et al. 2023. No random transits in CHEOPS observations of HD 139139. Astronomy & Astrophysics 680, A78.
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