TESS 2-minute light curves from 2018 to 2026 show no beta Pictoris-like exocomet transits in 24 other spectroscopic exocomet hosts; the pooled rate is below 2-30 percent of the beta Pic rate
Question: do the other stars with spectroscopic exocomet signatures also show the photometric exocomet transits that TESS sees in beta Pictoris? Approach: we searched all SPOC 2-minute light curves (sectors 1-107, 2018-2026) of the 30 hosts in Table 1 of Iglesias et al. (2025) and of 52 matched control A stars (391 light curves). We removed delta Scuti pulsations by prewhitening and used a matched filter with the 1-D exocomet model of Lecavelier des Etangs et al. (2022). Brightening events with the same filter give the false-alarm rate. Fixed rules remove events near gaps, momentum dumps, flagged data, background changes and centroid shifts. Completeness comes from 24,671 injections of the 30 published beta Pic events. Results: in beta Pic 2018-2021 the search finds 3 vetted dimming events (3.9 expected), and all 3 agree with published event times. In 24 other confirmed or candidate hosts it finds 0 vetted dimming and 3 brightening events in 2,102 days, where 71 detections are expected at the beta Pic rate. The 95% upper limit on the pooled rate is 1.9% of the beta Pic rate (4.6% if depth scales with stellar area), and 2.5-30% across all threshold, vetting, depth and self-calibration variants. HD 172555 gives 0 events where 4.8 are expected (limit 0.29). Matched controls give no dimming excess (8 vs 13). All host dimming candidates with D >= 6 are instrumental (background spikes, momentum-dump settling, orbit edges, scattered light). beta Pic itself gives 0 events in 2024-2025 where 3.1 are expected (p = 0.04), but this deficit is weak and threshold-dependent. Limitations: the search is sensitive mainly to events deeper than about 3.5e-4; the reference rate depends on the published beta Pic event list; seven hosts have near-zero completeness because of stellar variability; vetting rules were set after inspection of candidates, but the no-vetting variant gives the same conclusion.
exocomets · TESS · beta Pictoris · HD 172555 · falling evaporating bodies · debris discs · transit search · injection-recovery · null result · A-type stars
References
8- uses, reviewsdoi:10.1038/s41598-022-09021-2
Lecavelier des Etangs et al. (2022): 1-D exocomet model, the 30 beta Pic TESS events used for injection and as the reference rate.
- usesdoi:10.1007/s11214-025-01247-6
Iglesias et al. (2025), Table 1: list of stars with spectroscopic exocomet signatures (target sample).
- https://arxiv.org/abs/2508.04673
Norazman et al. (2025): automated exocomet search in TESS sectors 1-26 FFI data.
- https://arxiv.org/abs/2603.19978
Korth et al. (2026): review of exocomet observations; states the lack of joint photometric and spectroscopic detections.
- doi:10.1051/0004-6361/201935552
Zieba et al. (2019): first TESS exocomet transits of beta Pic.
- useshttps://arxiv.org/abs/2204.13618
Preprint of Lecavelier des Etangs et al. (2022) with Extended Data Table 2.
- useshttps://archive.stsci.edu/missions/tess/
TESS SPOC 2-minute light curves (MAST).
- useshttps://tess.mit.edu/public/target_lists/2m/
TESS 2-minute target lists used to select controls.
Cited by
0 publicationsPublic catalog entries on Sciscape.
No incoming citations on Sciscape.