- ID:
- ivo://CDS.VizieR/J/A+A/626/A38
- Title:
- Kepler-17 long-term photometry
- Short Name:
- J/A+A/626/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of young Sun-like stars is of fundamental importance to understand the magnetic activity and rotational evolution of the Sun. Space-borne photometry by the Kepler telescope provides unprecedented datasets to investigate these phenomena in Sun-like stars. We present a new analysis of the entire Kepler photometric time series of the moderately young Sun-like star Kepler-17 that is accompanied by a transiting hot Jupiter. We applied a maximum-entropy spot model to the long-cadence out-of-transit photometry of the target to derive maps of the starspot filling factor versus the longitude and the time. These maps are compared to the spots occulted during transits to validate our reconstruction and derive information on the latitudes of the starspots. We find two main active longitudes on the photosphere of Kepler-17, one of which has a lifetime of at least ~1400 days, although with a varying level of activity. The latitudinal differential rotation is of solar type, that is, with the equator rotating faster than the poles. We estimate a minimum relative amplitude {DELTA}{OMEGA}/{OMEGA} between ~0.08+/-0.05 and 0.14+/-0.05, our determination being affected by the finite lifetime of individual starspots and depending on the adopted spot model parameters. We find marginal evidence of a short-term intermittent activity cycle of ~48-days and an indication of a longer cycle of 400-600 days characterized by an equatorward migration of the mean latitude of the spots as in the Sun. The rotation of Kepler-17 is likely to be significantly affected by the tides raised by its massive close-by planet. We confirm the reliability of maximum-entropy spot models to map starspots in young active stars and characterize the activity and differential rotation of this young Sun-like planetary host.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/2877
- Title:
- Kepler M dwarf stars revised properties
- Short Name:
- J/MNRAS/457/2877
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We classified the reddest (r-J>2.2) stars observed by the NASA Kepler mission into main-sequence dwarf or evolved giant stars and determined the properties of 4216 M dwarfs based on a comparison of available photometry with that of nearby calibrator stars, as well as available proper motions and spectra. We revised the properties of candidate transiting planets using the stellar parameters, high-resolution imaging to identify companion stars, and, in the case of binaries, fitting light curves to identify the likely planet host. In 49 of 54 systems, we validated the primary as the host star. We inferred the intrinsic distribution of M dwarf planets using the method of iterative Monte Carlo simulation. We compared several models of planet orbital geometry and clustering and found that one where planets are exponentially distributed and almost precisely coplanar best describes the distribution of multiplanet systems. We determined that Kepler M dwarfs host an average of 2.2+/-0.3 planets with radii of 1-4R_{Earth}_ and orbital periods of 1.5-180d. The radius distribution peaks at ~1.2R_{Earth}_ and is essentially zero at 4R_{Earth}_, although we identify three giant planet candidates other than the previously confirmed Kepler-45b. There is suggestive but not significant evidence that the radius distribution varies with orbital period. The distribution with logarithmic orbital period is flat except for a decline for orbits less than a few days. 12 candidate planets, including two Jupiter-size objects, experience an irradiance below the threshold level for a runaway greenhouse on an Earth-like planet and are thus in a 'habitable zone'.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A15
- Title:
- Kepler-411 mid-transit times
- Short Name:
- J/A+A/624/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed characterization of the Kepler-411 system (KOI 1781). This system was previously known to host two transiting planets: one with a period of 3 days (R=2.4R_{Earth}_; Kepler-411b) and one with a period of 7.8days (R=4.4R_{Earth}_; Kepler-411c), as well as a transiting planetary candidate with a 58-day period (R=3.3R_{Earth}_; KOI 1781.03) from Kepler photometry. Here, we combine Kepler photometry data and new transit timing variation (TTV) measurements from all the Kepler quarters with previous adaptive-optics imaging results, and dynamical simulations, in order to constrain the properties of the Kepler-411 system. From our analysis, we obtain masses of 25.6+/-2.6M_{Earth}_ for Kepler-411b and 26.4+/-5.9M_{Earth}_ for Kepler-411c, and we confirm the planetary nature of KOI 1781.03 with a mass of 15.2+/-5.1M_{Earth}_, hence the name Kepler-411d. Furthermore, by assuming near-coplanarity of the system (mutual inclination below 30{deg}), we discover a nontransiting planet, Kepler-411e, with a mass of 10.8+/-1.1M_{Earth}_ on a 31.5-day orbit, which has a strong dynamical interaction with Kepler-411d. With densities of 1.71+/-0.39g/cm^3^ and 2.32+/-0.83g/cm^3^, both Kepler-411c and Kepler-411d belong to the group of planets with a massive core and a significant fraction of volatiles. Although Kepler-411b has a sub-Neptune size, it belongs to the group of rocky planets.
- ID:
- ivo://archive.stsci.edu/kepler_koi
- Title:
- Kepler Objects of Interest (KOI)
- Short Name:
- KOI CS
- Date:
- 12 Feb 2020 19:51:12
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- Launched in 2009, the Kepler Mission is surveying a region of our galaxy to determine what fraction of stars in our galaxy have planets and measure the size distribution of those exoplanets. Although Kepler completed its primary mission to determine the fraction of stars that have planets in 2013, it is continuing the search, using a more limited survey mode, under the new name K2. KOI is the Kepler Objects of Interest catalog listing observed Kepler targets which are flagged as potentially having exoplanets but may be false positives caused by other types of transient detection. This catalog is produced by the Kepler project and brought to MAST via NExScI.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/99
- Title:
- Kepler pipeline transit signal recovery. III.
- Short Name:
- J/ApJ/828/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With each new version of the Kepler pipeline and resulting planet candidate catalog, an updated measurement of the underlying planet population can only be recovered with a corresponding measurement of the Kepler pipeline detection efficiency. Here we present measurements of the sensitivity of the pipeline (version 9.2) used to generate the Q1-Q17 DR24 planet candidate catalog. We measure this by injecting simulated transiting planets into the pixel-level data of 159013 targets across the entire Kepler focal plane, and examining the recovery rate. Unlike previous versions of the Kepler pipeline, we find a strong period dependence in the measured detection efficiency, with longer (>40 day) periods having a significantly lower detectability than shorter periods, introduced in part by an incorrectly implemented veto. Consequently, the sensitivity of the 9.2 pipeline cannot be cast as a simple one-dimensional function of the signal strength of the candidate planet signal, as was possible for previous versions of the pipeline. We report on the implications for occurrence rate calculations based on the Q1-Q17 DR24 planet candidate catalog, and offer important caveats and recommendations for performing such calculations. As before, we make available the entire table of injected planet parameters and whether they were recovered by the pipeline, enabling readers to derive the pipeline detection sensitivity in the planet and/or stellar parameter space of their choice.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/38
- Title:
- Kepler planetary cand. VIII. DR25 reliability
- Short Name:
- J/ApJS/235/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4yr of Kepler time series photometry (Data Release 25, Q1-Q17: Twicken+, 2016, J/AJ/152/158). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it was able to separate TCEs caused by noise from those caused by low signal-to-noise transits. We discuss the Robovetter and the metrics it uses to sort TCEs. For orbital periods less than 100 days the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates between 200 and 500 days around FGK-dwarf stars, the Robovetter is 76.7% complete and the catalog is 50.5% reliable.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/L1
- Title:
- Kepler planet masses, radii and orbital periods
- Short Name:
- J/ApJ/880/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Structure in the planet distribution provides an insight into the processes that shape the formation and evolution of planets. The Kepler mission has led to an abundance of statistical discoveries in regards to planetary radius, but the number of observed planets with measured masses is much smaller. By incorporating results from recent mass determination programs, we have discovered a new gap emerging in the planet population for sub-Neptune-mass planets with orbital periods less than 20 days. The gap follows a slope of decreasing mass with increasing orbital period, has a width of a few M_{Earth}_, and is potentially completely devoid of planets. Fitting Gaussian mixture models to the planet population in this region favors a bimodel distribution over a unimodel one with a reduction in Bayesian information criterion of 19.9, highlighting the gap significance. We discuss several processes that could generate such a feature in the planet distribution, including a pileup of planets above the gap region, tidal interactions with the host star, dynamical interactions with the disk, with other planets, or with accreting material during the formation process.
- ID:
- ivo://archive.stsci.edu/kepler_published_planets
- Title:
- Kepler Published Planets
- Short Name:
- K Pub Planets
- Date:
- 12 Feb 2020 19:41:28
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- "Kepler Published Planets" is a catalog created from NExScI catalogs listing of published exoplanets found using Kepler. All included metadata is from the published paper.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A90
- Title:
- Kepler-419 radial velocities
- Short Name:
- J/A+A/615/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Kepler-419 is a planetary system discovered by the Kepler photometry which is known to harbour two massive giant planets: an inner 3M_J_ transiting planet with a 69.8-day period, highly eccentric orbit, and an outer 7.5M_J_ non-transiting planet predicted from the transit-timing variations (TTVs) of the inner planet b to have a 675-day period, moderately eccentric orbit. Here we present new radial velocity (RV) measurements secured over more than two years with the SOPHIE spectrograph, where both planets are clearly detected. The RV data is modelled together with the Kepler photometry using a photodynamical model. The inclusion of velocity information breaks the MR^-3^ degeneracy inherent in timing data alone, allowing us to measure the absolute stellar and planetary radii and masses. With uncertainties of 12 and 13% for the stellar and inner planet radii, and 35, 24, and 35% for the masses of the star, planet b, and planet c, respectively, these measurements are the most precise to date for a single host star system using this technique. The transiting planet mass is determined at better precision than the star mass. This shows that modelling the radial velocities and the light curve together in systems of dynamically interacting planets provides a way of characterising both the star and the planets without being limited by knowledge of the star. On the other hand, the period ratio and eccentricities place the Kepler-419 system in a sweet spot; had around twice as many transits been observed, the mass of the transiting planet could have been measured using its own TTVs. Finally, the origin of the Kepler-419 system is discussed. We show that the system is near a coplanar high-eccentricity secular fixed point, related to the alignment of the orbits, which has prevented the inner orbit from circularising. For most other relative apsidal orientations, planet b's orbit would be circular with a semi-major axis of 0.03au. This suggests a mechanism for forming hot Jupiters in multiplanetary systems without the need of high mutual inclinations.
190. Kepler Target Search
- ID:
- ivo://archive.stsci.edu/kepler_fov
- Title:
- Kepler Target Search
- Short Name:
- KIC_CT
- Date:
- 12 Feb 2020 19:50:32
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Kepler Target Search interface provides access to a 12.5 million row table created by MAST by joining entries from the Kepler Input catalog (KIC) with the Kepler Characteristics table (CT) and merging these with "associated" entries from the United Kingdom Infrared Telescope (IRT) project, the USNOb catalog, GALEX, the Kepler Isaac Newton Telescope Survey (KIS), and the Everett KPNO (UBV) survey. The search interface allows users to find targets within the Kepler field of view (FOV) and allows searches on magnitudes, colors, and other parameters for both KIC and associated non-KIC targets. This is the recommended interface for potential guest observers to locate possible targets for observation. GO proposers however should check on the target's position by either (or both) looking to one of our posted FFI images and seeing if it is on a chip, and (2) confirming this with the GO office.
