Transit Timing Observations From Kepler. Ix. Catalog of the Full Long-Cadence Data Set

Abstract

We present a new transit timing catalog of 2599 Kepler Objects of Interest (=KOIs), using the PDC-MAP long-cadence light curves that include the full seventeen quarters of the mission (ftp://wise-ftp.tau.ac.il/pub/tauttv/TTV/ver 112).The goal is to produce an easy-to-use catalog that can stimulate further analyses of interesting systems. For 779 KOIs with high enough SNRs, we derived the timing, duration and depth of 69,914 transits. For 1820 KOIs with lower SNR, we derived only the timing of 225,273 transits. After removal of outlier timings, we derived various statistics for each KOI that were used to indicate significant variations. Including systems found by previous works, we have detected 260 KOIs which showed significant TTVs with long-term variations (>100 day), and another fourteen KOIs with periodic modulations shorter than 100 day and small amplitudes. For five of those, the periodicity is probably due to the crossing of rotating stellar spots by the transiting planets. Subject headings: planetary systems-planets and satellites: detection-techniques: miscellaneous-technique: photometricwhere the p-value of the transit model exceeded 10 −4 , using an F -test relative to the no-transit assumption.• The transit depth was larger than 10%; those KOIs were ignored in order to disregard eclipsing binaries in our analysis, with the price of leaving out some "legitimate" transits such as large planets around M-stars.• The orbital period > 300 day; those KOIs were ignored due to too few transits for a significant TTV analysis.• KOIs identified as EBs, either listed in the Villanova eclipsing binary catalog, 2 as of 2014 July, or by McQuillan, Aigrain & Mazeh (2013).• KOIs identified by this study as false alarm, listed in Table 1, with some evidence for stellar binarity or pulsation.Following these cuts we were left with 2599 KOIs. We started by folding the PDC-MAP Kepler long-cadence 3 data, with the BJD T DB timings, using the ephemeris of NASA Exoplanet Archive, in order to obtain a good template for the transit light curve (see below for details). We used the best-fit transit model to measure the timing of each individual transit (=TT) and derived its O-C-the difference between the TT and the expected time, based on a linear ephemeris. As in Mazeh et al. (2013), for KOIs with high enough SNR (see below), the TT derivation was performed while allowing the duration and depth of each transit to vary.2The first step of our analysis was finding the continuum around each transit, ignoring the points in or near the transit itself, up to 0.7 transit durations around the expected timing of the transit center. Looking at a more extended region, up to two durations around the expected transit center, we fitted six different polynomials of degrees one to six to that region. The best fit was chosen as the one with the highest degree for which the p-value of all the F -tests with regard to polynomial fits of lower degrees was lower than 10 −3 . Finally, we added this polynomial back to the data during transit and divided ...

Eccentric Companions to Kepler-448b and Kepler-693b: Clues to the Formation of Warm Jupiters

“…I found clearly non-sinusoidal TTVs for Kepler-448/KOI-12b, Kepler-693/KOI-824b, and Kepler-419/KOI-1474b. The result is consistent with the TTV search by Holczer et al (2016), who reported significant long-term TTVs for the same three KOIs in our sample.…”

Dynamics and Formation of the Near-resonant K2-24 System: Insights from Transit-timing Variations and Radial Velocities

“…While ≈40% of Kepler planets are in multi-planet systems (Rowe et al 2014), planets typically need to be near mean-motion resonance to produce detectable TTVs. Holczer et al (2016) reported TTVs for ≈260 Kepler planets, but most are too faint for precision RV measurements with currentgeneration instruments, which typically require host stars with  V 13 mag. As a result, fewer than 10 systems have mass constraints from both the TTV and the RV techniques (Mills & Mazeh 2017).…”

The origin and 9:7 MMR dynamics of the Kepler-29 system

“…While we performed the TTV analysis of this data set after it has been published, we did not make an extensive use of the results. Our orbital models derived on the basis of the (Rowe et al 2015) catalogue fit the TTV time-series in Holczer et al (2016) as well. We have got qualitatively the same distributions of the best-fitting parameters.…”

“…Such a TTV variability is relatively clear as compared to other 2-planet systems in the KEPLER sample published in the (Rowe et al 2015) catalogue. Recently, Holczer et al (2016) performed a new re-analysis of the KEPLER data and they report 162 measurements for Kepler-29 that cover both the long-cadence and, when available, short-cadence KEPLER light-curves. While we performed the TTV analysis of this data set after it has been published, we did not make an extensive use of the results.…”

“…This is not yet a fully resolved issue, since most of the KEPLER systems are not sufficiently characterised, regarding both the planet's masses and orbital architectures. Dynamical modelling of Transit Timing Variation measurements (Agol et al 2005) or the photodynamical method (Carter et al 2011), which account for the mutual N-body interactions, are common and usually the only approaches making it possible to model multiple systems in the KEPLER sample (Rowe et al 2015;Mullally et al 2015;Holczer et al 2016). A further difficulty is a relatively narrow timewindow of observations and low signal-to-noise ratio that typically lead to weakly constrained eccentricities and longitudes of pericenter.…”