Kepler News and Results (Thread 2)

EPE has now included the batch of Kepler multiples, so there goes the argument that the non-inclusion is because the planets are regarded as contentious. I thought it might take them a while to get through all of that lot!

Hmm...the evidence for these new planets is purely statistical?

This reminds me of the old canard:

'Lies, damn lies, and statistics.'

As has been pointed out in multiple places on this site, there is a substantial number of dubious or spurious planets for which there was some evidence, at least initially. If I understood the linked article correctly, the evidence for many of these planets will remain purely statistical for the foreseeable future.

Even the supporters of these new 'statistical planets' fess up to there being 'serious amputations' later on.

Maybe another group, without connections to the first, should go over this info? Get at least some sort of independent confirmation? I find myself wondering how good the statistical models are.

So what exactly do you think was used to assess the credibility of the other planet candidates? Where do you think the error bars on the various planetary parameters are derived from if not statistics?

There might be good reasons to be sceptical of the latest planet batch, but "they used statistics" and a pithy adage is not one of them.

Revised properties for Kepler-9: lower masses for planets b and c and an increased radius for planet d:

Dreizler and Ofir, "Kepler-9 revisited 60% the mass with six times more data"
http://arxiv.org/abs/1403.1372

Quote :

So what exactly do you think was used to assess the credibility of the other planet candidates? Where do you think the error bars on the various planetary parameters are derived from if not statistics?

My apologies. To me, it just seems like they could have waited for additional confirmation before going public.

A Study of the Shortest-Period Planets Found With Kepler
http://arxiv.org/abs/1403.2379

If new < 1 d planets are found in known multi-planet systems. Do we get to consider these planets confirmed, too?

Now on arXiv
Kepler-210: An active star with at least two planets
http://arxiv.org/abs/1403.3238

http://news.discovery.com/space/alien-life-exoplanets/scientists-home-in-on-earth-sized-exoplanet-140320.htm

I Think it is KOI-571.05 in other words... Kepler-186 f!

Is any ttv signal detected?

Wow.  I suppose it was only matter of time before they found one.

Not a lot stated in the article though. Where can we find more?

-M-

Shporer et al. "Atmospheric Characterization of the Hot Jupiter Kepler-13Ab"
http://arxiv.org/abs/1403.6831

Revised planetary parameters. Atmosphere seems to be rather different to the other known hot Jupiter transiting an A-type star, WASP-33b. There also seems to be a mismatch between the mass estimate from Doppler beaming and from ellipsoidal variations, which has been seen in other systems with early type primaries, e.g. the A+WD system KOI-74.

KOI-368.01 as long period transiting planet??   

http://exoplanet.eu/catalog/koi-368.01/

http://arxiv.org/abs/1404.2960

Occurrence and core-envelope structure of 1--4x Earth-size planets around Sun-like stars

It's (probably) not related to the Kepler conference in a few hours, but here's a neat paper about Kepler phase curve photometry on numerous planets.

A comprehensive study of Kepler phase curves and secondary eclipses -- temperatures and albedos of confirmed Kepler giant planets
http://arxiv.org/abs/1404.4348

Quote :

We present a comprehensive study of phase curves and secondary eclipses in the Kepler data set using all available data from 15 quarters. Our original sample consists of 489 Kepler Objects of Interest (KOI) with R_p > 4 R_e , P < 10d, V_mag < 15 from the latest data release. Here we focus on 20 confirmed planets from that sample and derive their temperatures and albedos. Our results confirm and in most cases improve parameters derived by previous studies. We present new results for Kepler 1b-8b, 12b-15b, 17b, 40b, 41b, 43b, 44b, 76b, 77b, and 412b derived in a consistent manner. Furthermore we present a lightcurve analysis of Kepler 91b and Kepler 74b. Both show extra dimmings at times other than of the expected primary and secondary eclipses. Corrected for thermal emission we find the 20 planets we analyzed separate into two groups of high (>0.1) and low (<0.1) albedos, with no significant correlation to any stellar or planetary parameters. However the most massive planets from our sample are all low in albedo.

They might be subgiants...

Bastien et al. 'Larger Planet Radii Inferred from Stellar "Flicker" Brightness Variations of Bright Planet Host Stars'
http://arxiv.org/abs/1405.0940

The magnitude-limited nature of the sample introduces a bias where more subgiants are selected. This implies that the stars and hence the planets are on average larger than would otherwise be predicted.

Photo-Dynamical Analysis of Three Kepler Objects of Interest with Significant Transit Timing Variations

Quote :

KOI-227, KOI-319 and KOI-884 are identified here as (at least) two planet systems. For KOI-319 and KOI-884, the observed Transit Timing Variations (TTVs) of the inner transiting planet are used to detect an outer non-transiting planet. The outer planet in KOI-884 is 2.6 Jupiter masses and has the orbital period just narrow of the 3:1 resonance with the inner planet (orbital period ratio 2.93). The distribution of parameters inferred from KOI-319.01's TTVs is bimodal with either a 1.6 Neptune-mass (M_N) planet wide of the 5:3 resonance (period 80.1 d) or a 1 Saturn-mass planet wide of the 7:3 resonance (period 109.2 d). The radial velocity measurements can be used in this case to determine which of these parameter modes is correct. KOI-227.01's TTVs with large 10 hour amplitude can be obtained for planetary-mass companions in various major resonances. Based on the Bayesian evidence, the current TTV data favor the outer 2:1 resonance with a companion mass 1.5 M_N, but this solution implies a very large density of KOI-227.01. The inner and outer 3:2 resonance solutions with sub-Neptune-mass companions are physically more plausible, but will need to be verified.

KOI-884 = Kepler-247

In Kepler-247, they find TTVs in the third, outermost transiting 20-day planet that are not consistent with an origin in the inner two transiting planets (3 and 9 days), implying a fourth planet in the system. They designate the third outermost transiting planet KOI-844 b and the non-transiting fourth planet KOI-844 c.

Looks like this may be a case where the KOI-# and Kepler-# designations will mismatch the planet name letters.

pfff... Just like the KOI-314 mindcopulation.

The albedo of numerous Kepler super-Earths have been constrained.

The Albedos of Kepler's Close-in super-Earths
http://arxiv.org/abs/1405.3798

Quote :

Exoplanet research focusing on the characterization of super-Earths is currently limited to those handful targets orbiting bright stars that are amenable to detailed study. This Letter proposes to look at alternative avenues to probe the surface and atmospheric properties of this category of planets, known to be ubiquitous in our galaxy. I conduct Markov Chain Monte Carlo lightcurve analyses for 97 Kepler close-in $R_P \lesssim 2.0 R_{\oplus}$ super-Earth candidates with the aim to detect their occultations at visible wavelengths. Brightness temperatures and geometric albedos in the Kepler bandpass are constrained for 27 super-Earth candidates. A hierarchical Bayesian modeling approach is then employed to characterize the population-level reflective properties of these close-in super-Earths. I find median geometric albedos $A_g$ in the Kepler bandpass ranging between 0.16 and 0.30, once decontaminated from thermal emission. These super-Earths geometric albedos are statistically larger than for hot Jupiters, which have medians $A_g$ ranging between 0.06 and 0.11. A subset of objects, including Kepler-10b, exhibit significantly larger albedos ($A_g\gtrsim$0.4). I argue that a better understanding of the incidence of stellar irradiation on planetary surface and atmospheric processes is key to explain the diversity in albedos observed for close-in super-Earths.

Testing the Titius-Bode law predictions for Kepler multi-planet systems
http://arxiv.org/abs/1405.2259

http://astrobites.org/2014/05/19/testing-the-titius-bode-law-on-exoplanets/

The check to see if any of the Titus-Bode predictions correspond to actual planets in the Kepler data and are able to discover a few new planets, but far fewer than predicted.

New finds:
KOI-719 (Kepler-220). A ~Ganymede-sized planet at 15.77 days is identified. "The new signal is around the 7:4 resonance of both its inner neighbor and its outer neighbor."
KOI-1336 (Kepler-58). A 27.5 day planet, outside the 5:3 resonance with the inner planet, and near a 2:3 resonance with the outer planet.
KOI-1952 (Kepler-341). A 13.3 day planet near the 3:2 resonance of KOI-1952.01 and near 1:2 resonance with KOI-1952.02.
KOI-2722 (Kepler-402). A 16.5 day planet near the 3:2 resonance with the previous outermost planet candidate.
KOI-2859. A new 5.43 day signal.
KOI-733 (Kepler-224). A new planet candidate at 15.1 days.

I would like to know if is any ttv in kepler 220 and 402 systems, surely it would be very interesting to know the masses of planets

http://exoplanetarchive.ipac.caltech.edu./docs/exonews_archive.html#29May2014
Kepler-414 = KOI-341
Kepler-415 = KOI-1194
Kepler-416 = KOI-1860
Kepler-417 = KOI-2113

Another study of the Kepler-13 system.

Johnson et al. "A Misaligned Prograde Orbit for Kepler-13 Ab via Doppler Tomography"
http://arxiv.org/abs/1406.0512

Result is the projected misalignment between the planetary orbit is 58.6±2.0°, in conflict with the earlier determination by Barnes et al. (2011) of 23±4°.

They also constrain the tertiary star Kepler-13C to <0.75 solar masses at 95% confidence.

Planetary companions to sdB stars
http://arxiv.org/abs/1406.4711

Looks like there's another system in the Kepler data similar to the one at KOI-55, with multiple low-mass planet candidates in close orbit around an sdB star. The reference given is Silvotti et al. (2013), submitted to A&A but I haven't found anything after a quick search so not sure if it's been made available yet.

Other thing of note is that there is now a running program with HARPS-N to detect planets around sdB stars. One potential candidate so far (PG 0044+097).

http://adsabs.harvard.edu/abs/2014AAS...22334810S

PH3 b and C seems to be Kepler-289 b and c