Kepler News and Results

Its mass has not been measured and can be in the brown dwarf range.

Latest papers provide mass range between 2-9 Jupiter masses of 4-6 Mj, anyway.

Yes, the beaming/ellipsoidal effects should constitute a mass measurement, how reliable is another question (particularly with regards to the ellipsoidal measurements, apparently the theoretical background behind it doesn't work so well for stars without convection zones).

Weird EPE hasn't picked this up...

Spin-orbit resonance, transit duration variation and possible secular perturbations in KOI-13
http://arxiv.org/abs/1110.4231

Quote :

KOI-13 is the first known transiting system exhibiting light curve distortions due to gravity darkening of the rapidly rotating host star. In this paper we analyze publicly available Kepler Q2--Q3 short-cadence observations, detecting a continuous light variation with a period of Prot = 25.43 +- 0.05 hour and a half-amplitude of 21 ppm, which is linked to stellar rotation. This period is in exact 5:3 resonance with the orbit of KOI-13.01, which is the first detection of a spin-orbit resonance in a host of a substellar companion. The stellar rotation leads to stellar oblateness, which is expected to cause secular variations in the orbital elements. We indeed detect the gradual increment of the transit duration with a rate of (1.14 +- 0.30) * 10^{-6} day/cycle. The confidence of this trend is 3.85-sigma, the two-sided false alarm probability is 0.012%. We suggest that the reason for this variation is the expected change of the impact parameter, with a rate of db/dt = -0.016 +- 0.004/yr. Assuming b~0.25, KOI-13.01 may become a nontransiting object in 75--100 years. The observed rate is compatible with the expected secular perturbations due to the stellar oblateness yielded by the fast rotation.

It seems KOI-13 b gets three times the irradiation as WASP-33 b, and if I did the math right, has an equilibrium temperature of 3497 K.

SOPHIE velocimetry of Kepler transit candidates. V. The three hot Jupiters KOI-135b, KOI-204b and KOI-203b (alias Kepler-17b)
http://arxiv.org/abs/1110.5462

Quote :

We report the discovery of two new transiting hot Jupiters, KOI-135b and KOI-204b, that were previously identified as planetary candidates by Borucki et al. 2011, and, independently of the Kepler team, confirm the planetary nature of Kepler-17b, recently announced by Desert et al. 2011. Radial-velocity measurements, taken with the SOPHIE spectrograph at the OHP, and Kepler photometry (Q1 and Q2 data) were used to derive the orbital, stellar and planetary parameters. KOI-135b and KOI-204b orbit their parent stars in 3.02 and 3.25 days, respectively. They have approximately the same radius, Rp=1.20+/-0.06 R_jup and 1.24+/-0.07 R_jup, but different masses Mp=3.23+/-0.19 M_jup and 1.02+/-0.07 M_jup. As a consequence, their bulk densities differ by a factor of four, rho_p=2.33+/-0.36 g.cm^-3 (KOI-135b) and 0.65+/-0.12 g.cm-3 (KOI-204b). Our SOPHIE spectra of Kepler-17b, used both to measure the radial-velocity variations and determine the atmospheric parameters of the host star, allow us to refine the characterisation of the planetary system. In particular we found the radial-velocity semi-amplitude and the stellar mass to be respectively slightly smaller and larger than Desert et al. These two quantities, however, compensate and lead to a planetary mass fully consistent with Desert et al.: our analysis gives Mp=2.47+/-0.10 M_jup and Rp=1.33+/-0.04 R_jup. We found evidence for a younger age of this planetary system, t<1.8 Gyr, which is supported by both evolutionary tracks and gyrochronology. Finally, we confirm the detection of the optical secondary eclipse and found also the brightness phase variation with the Q1 and Q2 Kepler data. The latter indicates a low redistribution of stellar heat to the night side (<16% at 1-sigma), if the optical planetary occultation comes entirely from thermal flux. The geometric albedo is A_g<0.12 (1-sigma).

On The Existence Of Earth-like Planets In The Circumbinary System Kepler-16

Looks like you can fit an Earthlike planet in the Kepler-16 system habitable zone... (I'd guess this would need to be near the outer edge of the HZ as it is perilously close to the binary stars.)

Lack of Inflated Radii for Kepler Giant Planet Candidates Receiving Modest Stellar Irradiation
http://arxiv.org/abs/1110.6180

Quote :

The most irradiated transiting hot Jupiters are characterized by anomalously inflated radii, sometimes exceeding Jupiter's size by more than 60%. While different theoretical explanations have been applied, none of them provide a universal resolution to this observation, despite significant progress in the past years. We refine the photometric transit light curve analysis of 115 Kepler giant planet candidates based on public Q0-Q2 photometry. We find that 14% of them are likely false positives, based on their secondary eclipse depth. We report on planet radii vs. stellar flux. We find an increase in planet radii with increased stellar irradiation for the Kepler giant planet candidates, in good agreement with existing hot Jupiter systems. We find that in the case of modest irradiation received from the stellar host, giant planets do not have inflated radii, and appear to have radii independent of the host star incident flux. This finding suggests that the physical mechanisms inflating hot Jupiters become ineffective below a given orbit-averaged stellar irradiation level of ~2 10^8 erg s^-1 cm^-2.

Kepler Mission Manager Update.

Beginning of December should be interesting time...

Quote :

Finally, the Kepler Science Team is hosting the First Kepler Science Conference at NASA Ames Research Center Dec. 5-9, 2011. We are expecting more than 300 attendees at the conference. More than 200 abstracts have been submitted for presentation at the conference. Topics range from Earth-analog and sub-Neptune-size planets to multiple-planet systems to asteroseismology. This will be an opportunity to showcase not only the investigations of the Kepler Science Team, but also those of the wider science community using publicly accessible data from Kepler.

Mission Extension proposal.

Interesting to consider this modelling of giant planet migration in circumbinary discs from 2008, which predicts that Saturn-mass planets are more able to survive inward migration than Jupiter-mass ones in circumbinary discs.

Nice to see that Kepler-16 (AB) b is a Saturn-mass planet...

Detection of transit timing variations in excess of one hour in the Kepler multi-planet candidate system KOI 806 with the GTC

System contains three planets close to a 1:2:5 resonance (super-Earth, Saturn and Jupiter size planets)

Very interesting system as even black hole can exist in that system very large ttv

Kepler Science Conference schedule now up including abstracts. See here. Haven't looked through it yet but is worth a look.

As for a black hole in KOI-806, I don't think so... the TTVs are quite large but not compared to the orbital period, and the resonance makes large TTVs more likely.

Quote :

3:00 - 3:15 214 · The Multiple Planet System Kepler-20. Nick Gautier, Jet Propulsion Laboratory

So Kepler-20 is a multiple planet system. No other information yet...

Abstracts booklet suggests 5 candidate objects in Kepler-20 (=KIC 6850504, KOI-70), how many will be confirmed I wonder?

5 not 4 candidates around KOI 70?

I will be going to the Kepler conference; if any of you has a specific question to a specific person (almost everybody in the exoplanet transits will be there) ; I will do my best to ask it and report it here.

NASA Announcing Kepler Discoveries at Science Conference
http://www.nasa.gov/home/hqnews/2011/nov/HQ_M11-243_Kepler.html

Quote :

NASA will host a news briefing at 8 a.m. PST, Monday, Dec. 5, to announce new discoveries by the Kepler mission. The briefing, during the Kepler Science Conference, will be in building 152 at NASA's Ames Research Center at Moffett Field, Calif.

Quote :

The briefing will provide an update on the statistical findings since Kepler's Feb. 1, 2011, science data release and introduce a new confirmed planetary discovery.

A unique planet among the currently known.

Characterizing the Cool KOIs II. The M Dwarf KOI-254 and its Hot Jupiter
http://arxiv.org/abs/1112.0017

Quote :

We report the confirmation and characterization of a transiting gas giant planet orbiting the M dwarf KOI-254 every 2.455239 days, which was originally discovered by the Kepler mission. We use radial velocity measurements, adaptive optics imaging and near infrared spectroscopy to confirm the planetary nature of the transit events. KOI-254b is the first hot Jupiter discovered around an M-type dwarf star. We also present a new model-independent method of using broadband photometry to estimate the mass and metallicity of an M dwarf without relying on a direct distance measurement. Included in this methodology is a new photometric metallicity calibration based on J-K colors. We use this technique to measure the physical properties of KOI-254 and its planet. We measure a planet mass of Mp = 0.505 Mjup, radius Rp = 0.96 Rjup and semimajor axis a = 0.03 AU, based on our measured stellar mass Mstar = 0.59 Msun and radius Rstar = 0.55 Rsun. We also find that the host star is metal-rich, which is consistent with the sample of M-type stars known to harbor giant planets.

A young hot Jupiter orbiting a red dwarf. A real rarity, I agree

Lazarus wrote:

Abstracts booklet suggests 5 candidate objects in Kepler-20 (=KIC 6850504, KOI-70), how many will be confirmed I wonder?

From the abstract information I understand this five planets are confirmed or validated planets.

The size of the star given in the abstract is greater than in the candidate's paper. So if the dip is the same as initially found it means that this planets are smaller than they previously thought.

The fourth planet had a period of 78 days and it was near the inner edge of the HZ. So if the 5 planet has a longer period it could be the first transiting superearth in the HZ. I hope so.

On the other hand, I wonder what could be Kepler-13. Maybe another amazing announcement?

[quote="pochimax"]

Lazarus wrote:

The size of the star given in the abstract is greater than in the candidate's paper. So if the dip is the same as initially found it means that this planets are smaller than they previously thought.

It's the other way around. Scaling up the size of the star, the transit depths of its planets will shrink. So the planets must scale up as well to preserve the transit depth.

Transit depth = R_star / R_pl

I find this the Paper of the Kepler mission last presentation in September, But still they only show Kepler-13 in the Kepler field of view, but didn't say nothing about it...

but still there is some interest graphics and statistics about last planets candidates than they find.

the link:

http://ciera.northwestern.edu/Jackson2011/talks/batalha_natalie.pdf