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 ...

Following Ford et al. (2011, 2012b) and Steffen et al. (2012b) we derived the transit timing of 1960 Kepler KOIs using the pre-search data conditioning (PDC) light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough SNRs, we obtained also the duration and depth of each transit.The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations.Including systems found by previous works, we have found 130 KOIs that showed highly significant TTVs, and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV -the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

The mass of CoRoT-7b, the first transiting superearth exoplanet, is still a subject of debate. A wide range of masses have been reported in the literature ranging from as high as 8 M ⊕ to as low as 2.3 M ⊕ . Although most mass determinations give a density consistent with a rocky planet, the lower value permits a bulk composition that can be up to 50% water. We present an analysis of the CoRoT-7b radial velocity measurements that uses very few and simple assumptions in treating the activity signal. By only analyzing those radial velocity data for which multiple measurements were made in a given night we remove the activity related radial velocity contribution without any a priori model. We demonstrate that the contribution of activity to the final radial velocity curve is negligible and that the K-amplitude due to the planet is well constrained. This yields a mass of 7.42 ± 1.21 M ⊕ and a mean density of ρ = 10.4 ± 1.8 gm cm −3 . CoRoT-7b is similar in mass and radius to the second rocky planet to be discovered, Kepler-10b, and within the errors they have identical bulk densities -they are virtual twins. These bulk densities lie close to the density -radius relationship for terrestrial planets similar to what is seen for Mercury. CoRoT-7b and Kepler-10b may have an internal structure more like Mercury than the Earth.

KOI-13 was presented by the Kepler team as a candidate for having a giant planet -KOI-13.01, with an orbital period of 1.7 d and a transit depth of ∼0.8%. We have analyzed the Kepler Q2 data of KOI-13, which was publicly available at the time of the submission of this paper, and derived the amplitudes of the beaming, ellipsoidal and reflection modulations -8.6 ± 1.1, 66.8 ± 1.6 and 72.0 ± 1.5 ppm (parts per million), respectively. After the paper was submitted, Q3 data were released, so we repeated the analysis with the newly available light curve. The results of the two quarters were quite similar. From the amplitude of the beaming modulation we derived a mass of 10 ± 2 M Jup for the secondary, suggesting that KOI-13.01 was a massive planet, with one of the largest known radii. We also found in the data a periodicity of unknown origin with a period of 1.0595 d and a peak-to-peak modulation of ∼60 ppm. The light curve of Q3 revealed a few additional small-amplitude periodicities with similar frequencies. It seemed as if the secondary occultation of KOI-13 was slightly deeper than the reflection peak-to-peak modulation by 16.8 ± 4.5 ppm. If real, this small difference was a measure of the thermal emission from the night side of KOI-13.01. We estimated the effective temperature to be 2600 ± 150 K, using a simplistic black-body emissivity approximation. We then derived the planetary geometrical and Bond albedos as a function of the day-side temperature. Our analysis suggested that the Bond albedo of KOI-13.01 might be substantially larger than the geometrical albedo.

Mazeh, Holczer, and Shporer (2015) have presented an approach that can, in principle, use the derived transit timing variation (TTV) of some transiting planets observed by the Kepler mission to distinguish between prograde and retrograde motion of their orbits with respect to their parent stars' rotation.The approach utilizes TTVs induced by spot-crossing events that occur when the planet moves across a spot on the stellar surface, looking for a correlation between the derived TTVs and the stellar brightness derivatives at the corresponding transits. This can work even in data that cannot temporally resolve the spotcrossing events themselves. Here we apply this approach to the Kepler KOIs, identifying nine systems where the photometric spot modulation is large enough and the transit timing accurate enough to allow detection of a TTV-brightnessderivatives correlation. Of those systems five show highly significant prograde motion (Kepler-17b, Kepler-71b, KOI-883.01, KOI-895.01, and KOI-1074.01), while no system displays retrograde motion, consistent with the suggestion that planets orbiting cool stars have prograde motion. All five systems have impact parameter 0.2 b 0.5, and all systems within that impact parameter range show significant correlation, except HAT-P-11b where the lack of a correlation follows its large stellar obliquity. Our search suffers from an observational bias against detection of high impact parameter cases, and the detected sample is extremely small. Nevertheless, our findings may suggest that stellar spots, or at least the larger ones, tend to be located at a low stellar latitude, but not along the stellar equator, similar to the Sun.