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.

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.

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