KOI-1353 (KIC 7303287) – a third planet with marked TTVs

by kianjek

Originally described as a two-planet system by Batalha et al (2012), the Tenenbaum TCE claims an additional transit with P=65.9908.  This additional transit was also picked up by ajamyajax here back in May 2012, who also mentioned the TTVs.

Here’s a reprocessed light curve of KOI-1353 showing the 3 transit events. This new planet is marked in orange:


The light curve folded at the periods of 34 and 125 all reveal a reasonably accurate period.


The transit at 66d however, cannot be folded to give a clear unambiguous period (folded at 65.9908, the value as given in the TCE)


There are 15 transits. I ran the transits through TAP to get a model fit, and also recorded the midpoints of each transit.


The midpoints were then used to construct an O-C diagram. Note that the transits can be more than 7 hours late!


The period of the sine curve is approximately 1200d.