Tuesday, July 31, 2012

KIC 5558387 Possible Unlisted RR Lyrae Star at Planet Hunters

This Kepler light curve for star KID 5558379 is being contaminated  by an unlisted background RR Lyrae ( BG RRL) star. The phased curve cue for a possible RRL is shown below:


In this case, the star does not completely own its phased curve and is being contaminated from the BG RRL that is star KIC  5558387. Here is Kian Jek's comment:

"The APOs are significant, 5 and -10 millipixels, and the vector (brightening) points unambiguously to #3 KIC 5558387 as the source of the RRL-like pulsations. Unfortunately we don't know much about this star."

More information on the Talk thread here.

KID 5217733 Eclipsing Binary Super Contaminator



One of the obstacles to analyzing Kepler light curves is ruling out light contamination in the target star from background stars. Background eclipsing binary stars (BG EBs) are a real problem. KID 5217733 is a detached eclipsing binary star system with a magnitude of 7.4. This is a very bright star and as Kian Jek says, is a "Super Contaminator" affecting many nearby stars in the area.


Read more on this star on the Talk thread here.

Sunday, July 29, 2012

Hauling In The Nets On Kepler Q7 - Q9


It's been an exciting weekend for the amateur volunteers in the Planethunters community! With the release to the public realm of Kepler data for Quarters Seven through Nine, we've finally been able to re-characterize and re-examine a myriad of targets placed on watch lists at various points since the projects inception, looking for new and additional transits and eclipses.

No matter how many light curves we sift through in Classify or on the PH Talk forum it never gets old-- there is always something challenging to figure out waiting around the corner, and the past several days have been no exception to that rule. In addition to a host of new exoplanetary and binary star system candidates--some of which I'll highlight here--we've run into fresh new mysteries that will no doubt help keep everyone quite busy while we wait for the next public data release, and eventually the end of the proprietary period altogether as the extended mission proceeds.

Even with Kepler's exquisite light curve data quality, there are many considerations that could subsequently invalidate any of these suspected new objects, from blended background sources and astrophysical artifacts to software or hardware introduced issues. But we're confident many of them will hold up to future follow up performed by the scientific community in the months and years to come. 

It's also quite possible that with the the imminent release of a new Kepler Object of Interest catalog, some will immediately turn out to be co-discoveries made alongside our friends around the world with the big scopes; nonetheless it's a powerful testament to the skill of the human eye, and to good old fashioned teamwork!

Potential Exoplanet Candidates

KID 7826659
Possible 6.7xRe Habitable Zone Candidate with Period of ~211 days

KID 12735740
Possible 1.1xRj Habitable Zone Candidate with Period of ~282 days

KID 11253827
Possible Multplanetary System w/ a 4.0xRe at Period of ~42 days and a 6.49xRe at Period of ~88 days

KID 8827930
Possible 0.78xRj Candidate with a tentative Period of ~288 days

KID 5649325
Possible 0.96xRj Candidate with a Period of ~195 days

KID 11716643
Possible 3.8xRe Candidate with a tentative Period of ~466 days


Potential Stellar Companion Objects / Trinary Systems

KID 8164262

KID 6964043


KID 2856960



Probable Detached Eclipsing Binaries

KIDs
6756202,   P= ~292
7674050,   P= ~472
4586468,   P= ~506
7117003,   P= ~429
10074700, P= ~365
4663623,   P= ~359
7431665,   P= ~280

A big Thanks to everyone who took time out of their day (or night, as the case may be) to do some cross-checking and vetting with us this weekend!


KID 12735740 Possible Planet in Habitable Zone













Two transits for KID 12735740/ APH41073743  have been observed by Planet Hunters Talk members, up through quarter nine of the public data released by Kepler. Here is Kian Jek's comment:

"Just two transits so far but they stack so beautifully. Not only that, the profile is probably looking more like a PC (Planet Candidate) than an EB (Eclipsing Binary). Estimated 1.12x RJ planet at 0.862AU. With a Teq of 292K, it's in the HZ!"



Saturday, July 28, 2012

Amateur Kepler Observatory (AKO) at Planet Hunters

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 a thread on the Planet Hunters Science board called "AKO possible discoveries". Here is an example of an AKO graph  for KID 11853878 / KOI 1833 - two possible planet additions.
referenced here.



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.



Friday, July 27, 2012

Possible Trinary Star System KID 10091110

Possible Trinary Star system with great analysis by Talk members at Planet Hunters for KID  10091110 / APH51954360:



The Talk thread is well worth your time. Here is Kian Jek's comment:

"I don't think we're disputing that it's a circumbinary, but rather that it's a trinary, the third object isn't planetary, but most likely stellar - and from the 2:1 resonance seen, we just think it's very unlikely to be a blended BG EB. The Skyview doesn't show any elongated object, so if there is a blend, the 3rd light contaminant has to be very close, within 1-2" of the target.

Anyways, I've done a TTV analysis of the 3rd, 8.53d period eclipse. What I did was to take the first observed eclipse, treat this as T0, compute future eclipse timings from this and compare with each succeeding observed eclipse extremum. i.e. a straightforward O-C analysis. Here's my preliminary results. I think the picture tells a thousand words, no?




It looks like the minimum of each eclipse is arriving successively slower and then later. And it's not a trivial difference either - they are on the order of about 14 minutes earlier and later. After every tenth eclipse or so, it changes by double this amount and then reverts to the 14 minute interval again. I'm guessing the source of this third eclipse is therefore physically bound to this system.
Unless of course, it is from a blended EB, which itself has another 3rd object that is causing the TTVs of the blended eclipse. I think a certain William of Ockham would have some objections to that hypothesis..."


Jerry Orosz, Associate Professor, Department of Astronomy San Diego State University makes this comment:
 
"I think this is a blend of two unrelated EBs. There are two distinct periods in the light curve. There is an Algol-type light curve with a period of 4.21850952 days. The primary eclipse is a little over 2% deep, and the secondary eclipse (which appears at phase 0.5) is about 0.2% deep. The second signal has a period of 8.52998265 days, and only one eclipse is evident when phased at this period. The primary eclipse is nearly the same depth as the primary eclipse in the other light curve.



We often see light curves with only one eclipse per cycle. If the orbit is eccentric, the secondary eclipse can be missed. In the case of the longer period EB, it could be eccentric. If not, then we have a binary with twice that period where the two stars are equal, and the orbit is circular. One would need radial velocity measurements to be sure. I don't think these EBs are related since the respective O-C diagrams don't show any signals."

Tuesday, July 24, 2012

Dwarf Novae Candidates at Planet Hunters KIC 11412044, KIC 5565606, KID 10678185

Comment by Kian Jek:

"So far, Planet Hunters have found three background dwarf novae (DN) candidates in the Kepler public data, and we have worked out some basic characterizations of their properties as well as locations:

KIC 11412044 (see here)
KIC 5565606 (see here)
KIC 10678168 (see here) - the actual DN is suspected to be KIC 10678185

These were discovered at various times in the past with various contributions from many of us - I am just summarizing these here (on 6/30/2012) in the expectation that anybody trying to do a Google search of any of these Kepler IDs will be directed to this thread and continue to the discussions. If you have found these stars independently and plan to conduct some research on them, I simply request that you acknowledge our prior work and contributions. Please send correspondence to Meg Schwamb <megan.schwamb AT yale.edu>"

 KIC 11412044

 KIC 5565606


KIC 10678168 contaminated by suspected DN  KID 10678185




KIC 8416220 Pulsating Type M Red Subgiant

Quarter 3 Kepler light curve for  KIC 8416220 at Planet Hunters. This is a type M red subgiant star.

Here is comment by Kian Jek:

"As NHB has pointed out, this is a very unusual star because if its spectral type is correct (and the MAST entry seems incontrovertible, g-r and other measured bandpass magnitudes seem to agree that this is a Type M red subgiant), then it shouldn't be pulsating, and should not have multiple periods. A quick periodogram shows 2 dominant periods:



More information here.

KIC 8123430 Heartbeat Binary Candidate


Quarter 5 Kepler light curve at Planet Hunters for KIC 812343/APH51124541

Phased curve by Kian Jek:




KIC 12454613 Planet Candidate


Quarter 5 Light Curve for KIC 12454613 / APH52007327

Analysis by Kian Jek:


"No APOs seen and the normalized detrended transit plot looks quite convincing, rapid drop off, symmetrical shoulders and a flat-bottom with clustered data points. ~2.5 RE planetary object if the transit is real. Given that the transit duration is 15 hours, we should anticipate a long-period orbit ~ 1250 days, maybe more."

Monday, July 23, 2012

KIC 9715425 - Eruptive Variable Star

KIC 9715425 /APH22027710 is a spectral type A star, as listed at Planet Hunters, but may actually be a type B at 11199 (K). Tentatively tagged as a Gamma Doradus, it has eruptions through the quarters. First identified by Planet Hunters members one year ago.


This is what Talk member Kian Jek has to say about this star:

"This is an unusual one. There are no obvious APOs or contamination of any sort, so these spikes are a bit of a mystery. The pulsations continue right through these outbursts. In fact the pulsations resemble superhumps... could this yet be some strange species of dwarf nova? The double headed outburst at 340 appears to resemble the larger one at 600."

More ongoing updates at Planet Hunters here.

Sunday, July 22, 2012

KIC 3448777 Unlisted RR Lyrae Star at Planet Hunters


Ten months ago Planet Hunters Talk members found this interesting light curve for KIC 3448787 (APH23036769) which was subsequently analyzed and found to be contaminated by an unlisted RR Lyrae star with blazhko modulation. 



Phased curve showing pattern for RR Lyrae below.


 Here is the graph showing the blazhko modulation:


Here is what Chris Lintott (Zookeeper) posted back then:
 
Good news! I've heard back from our friends in the Kepler team, and this star is interesting and indeed new to them, so this is another #discovery for Planet Hunters! Congratulations, Tom128 (Tom Jacobs) for spotting it, and Kianjin (Kian Jek) for the analysis. They're going to do a detailed analysis - indeed, they've already started - and keep us informed. Obviously if it makes a paper then full credit will go to you two.

Some extra details; the reason that the variation appears and disappears between quarters might be because it's a background star; this would explain the small amplitude and if the processing used on different quarters included different parts of the image then that would explain why it comes and goes. They also say "Any new RRLs - especially the modulated ones - are of great value and very much appreciated! Kepler provides excellent light curves and delivers surprising new discoveries on #RRLyrae stars." so do tag anything you find.

As Robert Szabo, one of the scientists says : 'Congratulations to this precious discovery'.


Most likely star #4, KIC 3448777 and less likely star #5, KIC 3448767 are suspected to be the unlisted RR Lyrae star. Kian charted the APO vector due to the contamination which points in the direction of both stars.

https://mail-attachment.googleusercontent.com/attachment/?ui=2&ik=cfdaccf8d8&view=att&th=138e01d7f72f0ad3&attid=0.1&disp=inline&safe=1&zw&saduie=AG9B_P_fWMyEwvqJy97TrUk5AsN8&sadet=1343791656541&sads=knoqzo1Dw5DUsK4L-re9h6ODfFo


A PyKE analysis for the Kepler data, put together by Planet Hunters Daryll Lacourse, is shown below. You can see the Blazhko modulation in the upper right of the chart. Click here for a full view.


The good news is that Kepler has targeted star #4, KIC 3448777 and is studying it now.

Click here to read the Talk thread.
 




Planet Hunters Unlisted Planet Candidates 2012

Here is a list of Planet Hunters (PH) planet candidates that were identified by PH Talk members. Some stars may not be currently unlisted. The data below is provided by Kian Jek. One transit was identified by the Amateur Kepler Observatory (AKO). SPH ID is a unique identification of Kepler stars used at Planet Hunters. Scroll through the quarters to observe the transits. Here is the link to the complete planet candidate data set as an Excel spread sheet.

KID 3326377.02, KID 4472818, KID 4552729, KID 5563300, KID 6025124, KID 6058816, KID 6153672, KID 6507433, KID 6779260, KID 6878240, KID 7515679, KID 7810483, KID 7899070, KID 8326342, KID 8552719, KID 8564976, KID 9480535, KID 10360722, KID 11253827.01, KID 11253827.02, KID 11392618, KID 11551692.03


Kepler ID SPH ID
1 3326377.02 SPH10141397
2 4472818 SPH10106818
3 4552729 SPH10119459
4 5563300 SPH10127373
5 6025124 SPH10019042
6 6058816 SPH10068695
7 6153672 SPH10128926
8 6507433 AKO tool
9 6779260 SPH10075954
10 6878240 SPH22761749
11 7515679 SPH10033914
12 7810483 SPH10008599
13 7899070 SPH10031213
14 8326342 SPH10048401
15 8552719 SPH10066540
16 8564976 SPH10010298
17 9480535 SPH10111579
18 10360722 SPH10087907
19 11253827.01 SPH10080844
20 11253827.02 SPH10080844
21 11392618 SPH10137415
22 11551692.03 SPH10045214

Saturday, July 21, 2012

KID 11253827 Planet Hunters Multiplanet Candidate

This Kepler light curve for KID11253827 shows two planet transit candidates. Click here for more information.

An Automated Search for Transiting Exocomets- HD 182952 (KIC 8027456)

A team of astronomers led by Grant M. Kennedy , discovered a potential third comet system in the Kepler prime field data of HD 182952 (KIC...