KOI-351 (KIC 11442793)

by kianjek

KOI-351 or KIC 11442793,was listed in Batalha et al (2012) which identifies 3 planets with periods of  planet b, 59.738; planet e, 210.59; planet f, 331.64.

In March 2012, jiipee, ajamyajax (Mark) and Hans spotted some extra transits discussed in the Talk page here.

Here’s the results of my analysis of this object. I started by cleaning up and detrending the raw flux from Q1 to Q14. As our Planet Hunters had suspected, this star has at least 5 planets. There are TTVs in at least one planet, planet e. Planet f is probably in the HZ. Planets c and d are not described in the literature.

There are short cadence studies of this star from about BJD 809 onwards (Q9?) but strangely enough the transits of the smaller planets are very difficult to pick out in these data files.

The Tenenbaum TCE list has certain problems. There are 4 different transits cited. 210.595, 238.944, 179.214, 367.708. It appears to me that the only correct period is 210.595 for planet e.

The 238 and 179 values are wrong. They are multiples of 59.736, which is the period of planet b.

The TCE seems to have missed out planets c and d and the value for planet f, 367.708 seems at odds with the measured period of 331.646.

The light curve is here:


I folded the processed curve at each of the 5 periods, marked off the transits and ran the data through TAP to get light curve models for planets c and d.


Here’s a graphic of the relative sizes of the planets:


A scale diagram of the system with orbits of Earth (blue), Venus (orange) and Mercury (red) superimposed. Note how close b and c are to each other. All 5 planets fit just within Earth’s orbit. Could the proximity of planet f cause the TTVs seen in e? Or is there something else further out there?