Possible Exomoon Candidate transiting KIC 11152511

Kepler Q4 Light curve drop for KIC 11122511

Planet Hunters Talk member Khalin flagged this drop in Quarter four and Capella recently brought the transit forward from a collection of Tom128 for further analysis by forum members. There are some anomalies with this transit that may indicate the presence of an Exomoon. Though speculative at this point and time, more analysis is required as the hunt for a valid Exomoon continues at a fever pitch in the Kepler community.

ajamyajax

 

Yeah, could always be noise. The small gap in data here is what I saw though. There is a similar one on the other side in the earlier transit event. And not much in the third. So in theory anyway, this could be a large moon with its own periodic orbit. This recent article mentions that the first such finds will likely be large moons, which also got me thinking about that here:

"Alien Moons Could Host Life Outside 'Habitable Edge'"
http://news.yahoo.com/alien-moons-could-host-life-outside-habitable-edge-115714229.html





The complete Planet Hunters forum Talk thread for this transit follows:

cappella

I found this possible PC in Tom128's famous golden junk heap collection:
Q10 - day ~935 BJD

9 days ago

cappella

Q13 - day ~1223 BJD

9 days ago

cappella

We may have a candidate here with a period of ~288 days.
Unfortunately we don't have Q7 to verify the BJD ~650 transit, but there is one in Q41.

9 days ago

ajamyajax

 

Yes, looks like the same object in transit to me. And a new one not in any studies yet as far as I could see. I get a start of 360.815 BJD and a period of 287.342 with a maximum duration around 13.68 hours. And I didn't see any APO's with a glance at NEA. Here is a chart of the last two eclipses (thru q14) which are a little better than the first:

8 days ago

zoo3hans

According to the Planetary Calculator I get a 3.0 R_Earth planet @ 0.885 au from its 1.3 R_sol star with a period around 287.3 days and a temperature of 282 K, probably in the HZ.

8 days ago

ajebson

 

Here it is phased at 287.3673:

FULL

For the stellar parameters, I used Pinsonneault to infer values from the SDSS colours:

FULL

Here's a quick transit analysis constrained to zero eccentricity:

FULL


FULL

I'm a bit dubious about the exact timing of the 935 BJD transit.
Using this, it is 3.13 x Re @ 1.25AU with a Teff of 259K

8 days ago

ajamyajax in response to ajebson

ajebson:...

I'm a bit dubious about the exact timing of the 935 BJD transit.
Using this, it is 3.13 x Re @ 1.25AU with a Teff of 259K

I noticed that also, thought this one had TTV because of it. Just a disturbance in the flux :), or could that possibly be a moon?... Speculative of course, but in the HZ would make that a really neat find for PH... So I remain optimistic, as always.

8 days ago

ajebson

There's a high point followed by a two sample gap at the end of the transit, which makes it hard to be sure wher the transit ends - is the high point just noise, etc?

8 days ago

ajamyajax

 

Yeah, could always be noise. The small gap in data here is what I saw though. There is a similar one on the other side in the earlier transit event. And not much in the third. So in theory anyway, this could be a large moon with its own periodic orbit.
This recent article mentions that the first such finds will likely be large moons, which also got me thinking about that here:

"Alien Moons Could Host Life Outside 'Habitable Edge'"
http://news.yahoo.com/alien-moons-could-host-life-outside-habitable-edge-115714229.html

7 days ago

zoo3hans

Maybe David Kipping of Harvard should be alerted about this case. I have written an email to him.

ajebson

I wonder if we should do a more systematic search of all the HZ or near-HZ candidates for transit signatures as described-- Try this one and this

Also, there is one that troyw looked at that shows interesting TDVs which could just possibly be an exomoon.

7 days ago

ajamyajax in response to zoo3hans

zoo3hans:

Maybe David Kipping of Harvard should be alerted about this case. I have written an email to him.

I just e-mailed Dr Chris Lintott, thought he would like to know.

7 days ago

ajamyajax in response to ajebson

ajebson:

I wonder if we should do a more systematic search of all the HZ or near-HZ candidates for transit signatures as described here
Also, there is one that troyw looked at that shows interesting TDVs which could just possibly be an exomoon

Brilliant idea, many possibilities. You guys would be good at this, too.

about 3 hours ago

zookeeper (Chris Lintott)

Looks like an interesting case indeed! I'll ask the team and see what else we can dig up; from a quick glance I'm reasonably sceptical about the TTV - certainly one to watch for future quarters, though.
If anyone wanted a systematic search for exomoon signatures I think that'd be great, although I remain reasonably unconvinced that the Kepler data is good enough to show such a thing - noone would be happier than I to be proved wrong, though!

You can follow this star on the Forum Talk thread here.