Determine the origin and periodicity of the transit-timing residuals

Determine whether the 21.8-minute transit-timing residuals of TIC 402710280.01 arise from timing systematics or transit-timing variations induced by an additional body, and establish whether the residuals are periodic using additional transits.

Background

Four measured transit times for TIC 402710280.01 depart substantially from a weighted linear ephemeris, with an rms residual of 21.8 minutes compared with formal uncertainties of 1.7–3.3 minutes. The largest discrepancy is the 29-minute excess in the interval between the consecutive Sector 100 and Sector 102 transits.

The paper investigates several possible instrumental explanations but finds no identified instrumental cause. With only four observed epochs, the available data cannot distinguish systematic timing errors from genuine transit-timing variations caused by an additional body. Further transit observations are therefore required to determine the origin of the residuals and test whether they follow a periodic pattern.

References

We therefore identify no instrumental cause, and four epochs cannot distinguish timing systematics from transit-timing variations induced by an additional body. Additional transits will show whether the residuals are periodic.

— A 36.34-day Sub-Neptune Candidate Transiting the Nearby K Dwarf TIC 402710280  (2610.26056 - Vora, 19 Oct 2026) in Section 5.1, “Ephemeris and Timing Residuals” (Section \ref{sec:ttv})