Visual Phased Curve Drop of Kepler's Moon- sized Planet Transiting KIC 8478994

 

Phased curve of Moon-sized planet transiting KIC 8478994 by Kian Jek

troyw

 

AKO see's it, but just barely.
http://www.extrasolar.us/AKO/AKOimage.php?period=13.3673&KID=8478994&fixMin=2244231.5&fixMax=2244331.5

TTVs are also present it seems.

7 days ago

troyw

 

Should also be noted that this small fry was not picked up by the TCE.

7 days ago

mschwamb (science team) in response to troyw

troyw:
Should also be noted that this small fry was not picked up by the TCE.

Tom cites the Batalha candidates paper when discussing all three detections and they're listed as KOIs in the Feb 2012 candidate release. TCE doesn't catch everything in multiplanet systems and particularly with how small the transit signal with other frequent transit signals in the light curve, it that may not be so surprising. I know that for each KOI pwhere a transit has been detected they fit the transits remove them from the light curve and then search the light curve for additional transit signals with a BLS periodogram. i presume that's how they found the small guy.
~Meg

6 days ago

mschwamb (science team)

In case you want to look at the light curve data we have on the site - the star's id is SPH21167068
Cheers,
~Meg

about 1 hour ago

kianjin

This was an interesting one to test out one's power of observation, and the 39 and 21-day transits are quite readily apparent.




On the other hand, if I didn't know what the period of planet b, there is just no way it could have been picked up using the NEA periodogram service. Presumably the Kepler team has more sophisticated tools.


The transit can barely be picked out here - no surprise as it's just 36ppm, and Kepler's sensitivity threshold is 30ppm!

You can follow this planet at Planet Hunters forum Talk thread here. 

Amateur Kepler Observatory Identifies 15 Possible TTV Planet Candidates

Planet Hunters forum Talk member troyw has developed a novel program for analyzing Kepler light curves called the Amateur Kepler Observatory (AKO). Here is his introductory comment:

"AKO is web based software continually developed for viewing data from the Kepler Space Telescope. AKO is currently limited to long cadence data. AKO reads the data entered into its database and sorts that data in a specific way. The data is sorted into rows and columns, and each data point is represented by a grey colored box, usually 3 pixels by 3 pixels, on a dynamically generated image."

More detailed information here.

Troy has created a new thread on the Planet Hunters Science board called " Planetary Transit Timing Variation (TTV). The black horizontal lines are indications of a planet transit. One of the unique aspects of AKO is looking for Transit Timing Variations (TTVs) in the Kepler data for exoplanets. This is performed by stacking multiple quarters of the star's light curves.

troyw

15 potential TTV candidates, some of which I have posted elsewhere. KOI and KID numbers are as follows for this set:

KOI 374 KID 8686097
KOI 1162 KID 10528068
KOI 1245 KID 6693640
KOI 1273 KID 8806072
KOI 1412 KID 8950853
KOI 1831 KID 11601584
KOI 1914 KID 8426567
KOI 1934 KID 4242147
KOI 2037 KID 9634821
KOI 2062 KID 6774880
KOI 2094 KID 8505920
KOI 2125 KID 9405595
KOI 2166 KID 4370527
KOI 2291 KID 8410415
KOI 2351 KID 1872821

4 days ago

troyw

KOI 1582.01 KID 4918309

4 days ago

robert gagliano

Well done troyw. It would be very useful to have a comprehensive alphanumeric list of all TTVs (KIDs, KOIs, ect) found with AKO by everyone posted on this thread for crosschecking and updating. The TTVs currently are posted in multiple different threads. It's impossible to keep track. It would be nice to have one thread as "TTV Central".

4 days ago

troyw

Yeah, that's sort of the idea, although I'd rather keep stellar TTVs separate from the planetary ones. I'll make another thread when I get the time for the stellar TTV candidates.

3 days ago

planetsam

Don't forget KOI 868 - KID 6867155

New Planet Candidates Transiting KIC 7303287 and KIC 11442793 Multiple Planet Systems

Artist concept of KIC 11442793 with five transiting planets by Kian Jek


Planet Hunters forum Talk member Kian Jek has recently started a blog with his analyses on interesting discoveries at Planet Hunters. KIC 7303287 and KIC 11442793 are two known stars with multiple transiting planets that have been shown to have transit timing variations ( TTVs ) indicating new and previously undiscovered planets orbiting these stars. Click here to visit Kian's site for more information.

KIC 6850665 - Possible New Class of Tidally Distorted Eclipsing Binary Stars

     KIC 6850665 at Quarter 14 - NEA


Planet Hunters forum Talk member Planetsam flagged this unusual light curve drop in Q3. It may be a new class of  tidally distorted eclipsing binary type K stars.

Kian Jek:

Nice deductive work guys, it's very likely that this is also some sort of eccentricity induced tidal distortion superimposed with an eclipse, and I agree that KID 10614012 is probably similar. This is very interesting because it means we may have at least 3 Type K stars exhibiting this effect. I've cleaned up and detrended the light curve, preserving the eccentric pulse:

           And a close-up of the 2 transits stacked with each other:

Those little discontinuities are present at the ingress and egress, similar to KIC 10614012.

 zoo3hans:

There's no doubt about the period now, about 214.75 days.

   nighthawk_black:

 Strange--is this just some variation from one of the components that is not being 'overwritten' during the close passage--or something else?

These features can be seen in the sap_raw as well.



As Planetsam has pointed out in APH52025928, there is an interesting reminiscence to SPH10004034 on this target.

UKIRT

You can follow this star at Planet Hunters forum Talk here.

Unlisted Super Earth Candidate transiting KIC 6587796

Planet Hunters Q7.3 Light Curve for KIC 6587796


Planet Hunters Talk member Dolorous Edd  has identified an unlisted 1.53 relative Earth size planet transiting KIC 6587796. The transit was also flagged by Planet Hunters member Steve-1759 in Q4 Though the transit is listed in the Kepler Transit Crossing Event Archive for 2012, it has not been characterized as a planet transit.

Kian Jek:

Very nice find. Even though it's in the TCE list (Tenenbaum et al 2012), it's not characterized as a planet. After detrending and cleaning up, the transits are very clear.

Eyeballing the phased curve (folded at 33.4203) reveals that it has a very nice planetary profile. A modeling run with TAP gives these:

The parameters I obtained from TAP are slightly different from the TCE. Depth of 340 ppm, duration 4.93 hr, impact parameter of 0.044, a=0.197AU, Rp=1.53xRE (yes, Super Earth!) and a Teq of 537K.

 

UKIRT 1'x1' image looks good - but could there be something at 2 o'clock?

Folded stacked pixel centroids plot doesn't show any APOs.

You can follow this planet candidate at Planet Hunters forum Talk here.