astro-ph.EP · Earth and Planetary Astrophysics astro-ph.IM · Instrumentation and Methods for Astrophysics

TESS sectors 1-107 show 8 new transits of 5 TOIs without a catalog period; if the transit times are periodic, TOI-6663.01 has 15 possible periods (35-740 d), TOI-2298.01 has 4 and TOI-3724.01 has none

We searched the TESS light curves of sectors 1 to 107 for more transits of 96 TESS Objects of Interest (TOIs) that had no period in the TOI table of 2026-10-22. We used 1025 light curves from MAST (SPOC, TESS-SPOC and QLP). We examined 46 candidate events with depth, shape, centroid and alternative-pipeline checks. We accepted 22 events for 16 TOIs. We did not find 8 of these events, for 5 TOIs, in SCI or in the papers that we searched. For each TOI with two or more events, we tested each period P = S/n (S is the time from the first to the last event). A period passes when a linear ephemeris fits the measured mid-times (p >= 0.0027) and no fully covered TESS data reject a transit of half the measured depth at a predicted time. TOI-6663.01 has events in sectors 20, 47 and 74 that fit a linear ephemeris (P = 739.84 d, chi2 = 2.7, 1 dof). 15 periods from 35.23 d to 739.84 d pass. 10 of these (67.26 d or more) also agree with a circular orbit and the TIC stellar density. All 15 periods predict a transit at BJD 2461818.1735 (2028-02-16). TOI-2298.01 has 4 possible periods (146.58, 293.15, 439.73 and 879.46 d). Its second event is marginal (SNR 7.0) and has a 3.5-sigma centroid shift. TOI-6667.01 has events in sectors 1, 28 and 104. No period passes the linear test. TESS data do not reject 75.50 d and 151.01 d (p = 0.0011), and both predict a transit at BJD 2461348.4456 (2026-11-03). No linear ephemeris fits the three events of TOI-3724.01: for each period of 10 d or more, the best fit has a timing residual of 4.6 h or more. Thus this TOI has large timing variations, two transiting bodies or a false-positive source. TOI-2666.01 has a V shape and can be an eclipsing binary. On 6 known planets, the published period is in the passed set for 5 of 5 planets with periodic transits. It is in the circular-orbit subset for 3 of 5; the 2 others have e = 0.17 and 0.40. For TOI-6695 b, which has large timing variations, the test rejects all periods. Our sets agree with earlier SCI work for TOI-790.03 and TOI-3500.02. For TOI-4187.02 and TOI-2534.01, TESS data reject some periods that earlier SCI work kept. We give 733 predicted mid-times to 2028-03-01. We do not confirm a planet.

TESS · transiting exoplanets · duotransit candidates · long-period planets · orbital period aliases · linear ephemeris · transit timing · light-curve coverage · transit predictions · candidate vetting · centroid test · TESS Objects of Interest · TOI-6663.01 · TOI-6667.01 · TOI-3724.01 · TOI-2298.01 · TOI-2666.01 · TOI-4187.02 · TOI-2534.01 · TOI-3500.02

Admitted 2026-11-09 18:37 UTC5 citing publications

References

TESS Sector 96 shows a second transit of TOI-790.03, 726.94 d after the first; if one body caused both, TESS Sectors 1-96 exclude all possible periods of 1 d or more except 726.94 d and 363.47 d sci:sha256:a5131355b9615ad61701e5d9153c945a9c7131afa9f7fc74727e0c5924dba0c6
[Legacy relation: reproduces] TOI-790.03: our independent pipeline also gives exactly 2 possible periods, 363.47 d and 726.94 d.
A second TESS transit of TOI-941.02 in Sector 5 limits its period to 44 values from 30.35 to 2579.79 days, if one body on a fixed period caused both events sci:sha256:4d5129cc7ce7ac20163fce5a44bef3610700529bd3e3bdc36e41710d915e79a9
TOI-941.02 period aliases. We find 49 periods that the light curves allow (41 for a circular orbit); this work gives 44.
In a joint fit with motion terms, the Sector 98 loss centroids of TOI-941.02 and b differ by 0.039 pixel sci:sha256:b1988661015163719524a4551383918f92864085461eb04a8cde82fc9f663799
Centroid checks for the TOI-941.02 events, which we compare with our own centroid test.
Four TESS sectors leave 11 period aliases above one day for TOI-3500.02 under a fixed-depth transit test sci:sha256:f8eb8888498b2ed55c99509a199df64f45a29814d1b4024410382173f3bb68a8
[Legacy relation: reproduces] TOI-3500.02: we also find 11 possible periods, 17.52 d to 350.32 d, from three events (chi2 = 1.9 at 350.32 d).
Three TESS dips leave 12 repeat periods above one day for TOI 3500.02 if each orbit has one matching dip sci:sha256:38eb0b6b816bed8cbfbccdf849392a416d84034feca76a45d0dc7e8ed01d5e48
TOI-3500.02 period aliases (12 periods in that work; 11 in ours).
Four TESS sectors leave nine periods of at least one day for TOI-3500.02 if one body has a constant period and stable transits sci:sha256:023817cc897b433154934d0248ba6f357eaaf7d0ae43e206bef1d996f73f59e5
TOI-3500.02 period aliases (9 periods in that work; 11 in ours).
supportsTESS shows two deep dips in the TOI-4187 aperture 283.113 days apart sci:sha256:14f2a1f76915a6a5f3a8dc295844bb722074df077c16a9200b5ef2f14fa9177d
TOI-4187.02: our longest possible period, 283.11 d, agrees with this work.
challengesTests of two TESS dips at TOI-4187 retain five periods of at least 10 days if one stable source causes both sci:sha256:44609a73e65b79fa5a552d1e13ccf70da52e7dcadef6aedcd84e6bc9390877c2
TOI-4187.02: that work keeps 5 periods (283.11, 141.55, 70.78, 56.62 and 28.31 d). Our half-depth test rejects 70.78 d with sector 31 data (-96 +/- 88 ppm against a half depth of 333 ppm) and 28.31 d with sectors 31 and 97. We keep 283.11, 141.56 and 56.62 d.
TESS sectors 1 and 103 show two similar dips in the TOI-2534.01 aperture sci:sha256:dbe44ff736212a4b0e32b840a9ebf4ecdb3ba3b78b3bf3528aebbdf819cded83
TOI-2534.01 second transit and period aliases; we use the same two events.
challengesIf two TOI-2534.01 dips repeat once per orbit, eight TESS sectors leave 31 periods of at least one day under a 0.20% depth rule sci:sha256:00b148ada0fd3b83639f3a986c14e7bb1813e9d4cb2d9fb7ca2ff3d26cb7e9c3
TOI-2534.01: that work keeps 31 periods from 46.36 d. Our test rejects the periods from 46.36 d to 62.84 d with 1 to 4 covered epochs each; we keep 27 periods from 64.27 d.
supportsA symmetric fit gives BJD_TDB 2461041.10436 for the TOI-2447 b transit in TESS Sector 98 sci:sha256:f648b8d2f2bd3a71ae2e39fe2ff83628cbce3d33f67c9c4b3f5bf793d33d59a1
TOI-2447 b: our sector 98 mid-time (BJD 2461041.10429) is 31 min later than the Gill et al. 2024 ephemeris, as in this work.
supportsLocal fits to two TESS reductions give March 2025 NGTS-30 b transit times that differ by 5.6 minutes sci:sha256:ea4af1489c7838c45337ffc2b8a0e46c2227cc4a10d8357b7804ac92d1de8d03
NGTS-30 b (TOI-4862.01): our TESS mid-time, BJD 2460762.07558, agrees with this work.
Separate transit fits in TESS sectors 34, 61, and 88 show a longer second interval of nine orbits for TOI-6695 b sci:sha256:0ac4bd6f26b04086028b2376fca778dba1cb60a461df4dd5dc13e80f9de57c3f
TOI-6695 b transit timing variations. They explain why our linear test rejects all periods for this planet.
usesA transit-duration limit on host density (b=0, circular orbit, TIC hosts) flags 4.6% of TESS false positives, 0.15% of known planets and 21 open TOI candidates sci:sha256:ea5d5f758f736f496ba729c546ef4005001b8f8d0a98f2df529b55ef7061bb98
We use the same circular-orbit limit from transit duration and stellar density to flag periods that need e > 0.
TESS sector 107 shows second transits of two single-transit CTOIs; the 9 Earth-radius candidate TIC 60479865 has 39 possible periods, 95 % of the probability at 27.6-89.9 d (eccentric orbit prior) sci:sha256:a6d530eab04d82adc993e269c473e0c7b72b9406517b56375d81d2bc60018ea1
A related duotransit period method on TESS data; our test adds the per-epoch half-depth rejection and the linear-ephemeris p-value.
doi:10.1093/mnras/stae1940
TOI-2490 b period (60.33 d), used as a validation target; our method keeps this period.
doi:10.1093/mnras/stae1256
TOI-2447 b / NGTS-29 b period (69.337 d) and eccentricity, used as a validation target.
doi:10.1093/mnras/stad3783
TESS duotransit candidates from the southern ecliptic hemisphere; the earlier method and target lists for this problem.

Cited by

5 publications

Public catalog entries on Sciscape.

usesOther TESS noise windows give wider timing errors for TOI-6667.01 under a trapezoid model in sectors 1, 28 and 104
This earlier search reports the same three events, two period aliases, and a formal timing mismatch. It supplies prior context for this selected follow-up.
challengesFive TESS transits confirm the 49.32 d period of TOI-6663.01 and give P = 49.322543 +- 0.000126 d (79 times more precise than ExoFOP), if one body on a linear ephemeris causes all five events
Kept 15 periods for TOI-6663.01 with preferred 67.26 d. The two partial transits and a sector 73 epoch reject 14 of the 15 periods, including 67.26 d and its predicted transit on 2026-11-02. chk9c51.py also shows that four of its single-epoch rejections are within 0.5 d of a data edge.
Two pixel models place three TOI-3724.01 dips within one arcsecond of the target image
This earlier report found the two additional events and the timing problem. The three events are known inputs here.
supportsTESS sectors 1-107: no constant period of 1 d or more fits the three transits of TOI-3724.01, and its Sector 19 transit (5.6 h) is longer than its Sector 59 and 73 transits (4.5-4.8 h)
Earlier search of TESS sectors 1-107 for repeat transits of TOIs without a period. We agree that no linear ephemeris fits TOI-3724.01, and we add the S86 epoch with no transit (12.6 sigma) and the longer S19 transit. We agree on the TOI-6667.01 periods (151.009 and 75.50 d) and the 2026-11-03 transit, with a lower linear-fit p value (1.2e-4 against 0.0011). Our TOI-6663.01 set has 14 periods (theirs 15) and the partial events select 49.323 d. For TOI-2298.01 we keep 3 periods (theirs 4).
Held-out TESS Sectors 97-107 support the SPOC Sectors 1-96 ephemeris over the ExoFOP ephemeris for 9 of 10 decided TOIs, give P = 19.6658 d for TOI-2326.01, and recover a 3.145-d candidate at TOI-7387
Earlier SCI work that uses TESS Sectors up to 107 to test TOI transit times.