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- ID:
- ivo://CDS.VizieR/J/ApJ/790/31
- Title:
- Transit times and durations of three KOIs
- Short Name:
- J/ApJ/790/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 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 days) or a =~1 Saturn-mass planet wide of the 7:3 resonance (period 109.2 days). 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 hr 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/785/15
- Title:
- Transit times for Kepler-79's known planets
- Short Name:
- J/ApJ/785/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Kepler-79 (KOI-152) has four planetary candidates ranging in size from 3.5 to 7 times the size of the Earth, in a compact configuration with orbital periods near a 1:2:4:6 chain of commensurability, from 13.5 to 81.1 days. All four planets exhibit transit timing variations with periods that are consistent with the distance of each planet to resonance with its neighbors. We perform a dynamical analysis of the system based on transit timing measurements over 1282 days of Kepler photometry. Stellar parameters are obtained using a combination of spectral classification and the stellar density constraints provided by light curve analysis and orbital eccentricity solutions from our dynamical study. Our models provide tight bounds on the masses of all four transiting bodies, demonstrating that they are planets and that they orbit the same star. All four of Kepler-79's transiting planets have low densities given their sizes, which is consistent with other studies of compact multiplanet transiting systems. The largest of the four, Kepler-79 d (KOI-152.01), has the lowest bulk density yet determined among sub-Saturn mass planets.
- ID:
- ivo://CDS.VizieR/J/AJ/154/64
- Title:
- Transit times of Kepler-448b and Kepler-693b
- Short Name:
- J/AJ/154/64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I report the discovery of non-transiting close companions to two transiting warm Jupiters (WJs), Kepler-448/KOI-12b (orbital period P=17.9days, radius R_p_=1.23_-0.05_^+0.06^R_Jup_) and Kepler-693/KOI-824b (P=15.4days, R_p_=0.91+/-0.05R_Jup_), via dynamical modeling of their transit timing and duration variations (TTVs and TDVs). The companions have masses of 22_-5_^+7^M_Jup_ (Kepler-448c) and 150_-40_^+60^M_Jup_ (Kepler-693c), and both are on eccentric orbits (e=0.65_-0.09_^+0.13^ for Kepler-448c and e=0.47_-0.06_^+0.11^ for Kepler-693c) with periastron distances of 1.5au. Moderate eccentricities are detected for the inner orbits as well (e=0.34_-0.07_^+0.08^ for Kepler-448b and e=0.2_-0.1_^+0.2^ for Kepler-693b). In the Kepler-693 system, a large mutual inclination between the inner and outer orbits (53_-9_^+7^deg or 134_-10_^+11^deg) is also revealed by the TDVs. This is likely to induce a secular oscillation in the eccentricity of the inner WJ that brings its periastron close enough to the host star for tidal star-planet interactions to be significant. In the Kepler-448 system, the mutual inclination is weakly constrained, and such an eccentricity oscillation is possible for a fraction of the solutions. Thus these WJs may be undergoing tidal migration to become hot Jupiters (HJs), although the migration via this process from beyond the snow line is disfavored by the close-in and massive nature of the companions. This may indicate that WJs can be formed in situ and could even evolve into HJs via high-eccentricity migration inside the snow line.
- ID:
- ivo://CDS.VizieR/J/A+A/577/A109
- Title:
- Transit times of Qatar-1b
- Short Name:
- J/A+A/577/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The transiting hot Jupiter planet Qatar-1 b was presented to exhibit variations in transit times that could be of perturbative nature. A hot Jupiter with a planetary companion on a nearby orbit would constitute an unprecedented planetary configuration, important for theories of formation and evolution of planetary systems. We performed a photometric follow-up campaign to confirm or refute transit timing variations. We extend the baseline of transit observations by acquiring 18 new transit light curves acquired with 0.6-2.0 m telescopes. These photometric time series, together with data available in the literature, were analyzed in a homogenous way to derive reliable transit parameters and their uncertainties. We show that the dataset of transit times is consistent with a linear ephemeris leaving no hint for any periodic variations with a range of 1 min. We find no compelling evidence for the existence of a close-in planetary companion to Qatar-1 b. This finding is in line with a paradigm that hot Jupiters are not components of compact multi-planetary systems. Based on dynamical simulations, we place tighter constraints on a mass of any fictitious nearby planet in the system. Furthermore, new transit light curves allowed us to redetermine system parameters with the precision better than that reported in previous studies. Our values generally agree with previous determinations.
- ID:
- ivo://CDS.VizieR/J/ApJS/197/2
- Title:
- Transit timing observations from Kepler. I.
- Short Name:
- J/ApJS/197/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The architectures of multiple planet systems can provide valuable constraints on models of planet formation, including orbital migration, and excitation of orbital eccentricities and inclinations. NASA's Kepler mission has identified 1235 transiting planet candidates. The method of transit timing variations (TTVs) has already confirmed seven planets in two planetary systems. We perform a transit timing analysis of the Kepler planet candidates. We find that at least ~11% of planet candidates currently suitable for TTV analysis show evidence suggestive of TTVs, representing at least ~65 TTV candidates. In all cases, the time span of observations must increase for TTVs to provide strong constraints on planet masses and/or orbits, as expected based on N-body integrations of multiple transiting planet candidate systems (assuming circular and coplanar orbits).
- ID:
- ivo://CDS.VizieR/J/ApJS/208/22
- Title:
- Transit timing variation for 12 planetary pairs
- Short Name:
- J/ApJS/208/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extract transit timing variation (TTV) signals for 12 pairs of transiting planet candidates that are near first-order mean motion resonances (MMR), using publicly available Kepler light curves (Q0-Q14). These pairs show significant sinusoidal TTVs with theoretically predicted periods, which demonstrate these planet candidates are orbiting and interacting in the same system. Although individual masses cannot be accurately extracted based only on TTVs because of the well-known degeneracy between mass and eccentricity, TTV phases and amplitudes can still place upper limits on the masses of the candidates, confirming their planetary nature. Furthermore, the mass ratios of these planet pairs can be relatively tightly constrained using these TTVs. The planetary pair in KOI 880 seems to have particularly high mass and density ratios, which might indicate very different internal compositions of these two planets. Some of these newly confirmed planets are also near MMR with other candidates in the system, forming unique resonance chains (e.g., KOI 500).
- ID:
- ivo://CDS.VizieR/J/ApJS/210/25
- Title:
- Transit timing variation for 15 planetary pairs. II.
- Short Name:
- J/ApJS/210/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Following on from Paper I (Cat. J/ApJS/208/22) in this series, I report the confirmation of a further 30 planets in 15 multiple-planet systems via transit timing variations (TTVs), using the publicly available Kepler light curves (Q0-Q16). All 15 pairs are near first-order mean motion resonances, showing sinusoidal TTVs consistent with theoretically predicted periods, which demonstrate they are orbiting and interacting in the same systems. Although individual masses cannot be accurately extracted based only on TTVs (because of the well known degeneracy between mass and eccentricity), the measured TTV phases and amplitudes can still place relatively tight constraints on their mass ratios and upper limits on their masses, which confirm their planetary nature. Some of these systems (KOI-274, KOI-285, KOI-370, and KOI-2672) are relatively bright and thus suitable for further follow-up observations.
- ID:
- ivo://CDS.VizieR/J/AJ/154/5
- Title:
- Transit timing variations of 145 Kepler planets
- Short Name:
- J/AJ/154/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conduct a uniform analysis of the transit timing variations (TTVs) of 145 planets from 55 Kepler multiplanet systems to infer planet masses and eccentricities. Eighty of these planets do not have previously reported mass and eccentricity measurements. We employ two complementary methods to fit TTVs: Markov chain Monte Carlo simulations based on N-body integration, and an analytic fitting approach. Mass measurements of 49 planets, including 12 without previously reported masses, meet our criterion for classification as robust. Using mass and radius measurements, we infer the masses of planets' gaseous envelopes for both our TTV sample and transiting planets with radial velocity observations. Insight from analytic TTV formulae allows us to partially circumvent degeneracies inherent to inferring eccentricities from TTV observations. We find that planet eccentricities are generally small, typically a few percent, but in many instances are nonzero.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A92
- Title:
- Transit timing variations on Qatar-1
- Short Name:
- J/A+A/555/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Variations in the timing of transiting exoplanets provide a powerful tool detecting additional planets in the system. Thus, the aim of this paper is to discuss the plausibility of transit timing variations on the Qatar-1 system by means of primary transit light curves analysis. Furthermore, we provide an interpretation of the timing variation. We observed Qatar-1 between March 2011 and October 2012 using the 1.2m OLT telescope in Germany and the 0.6m PTST telescope in Spain. We present 26 primary transits of the hot Jupiter Qatar-1b. In total, our light curves cover a baseline of 18 months. We also refine the ephemeris of Qatar-1b, which we find to be T0=2456157.42204+/-0.0001BJD_TDB_ and P=1.4200246+/-0.0000007 days, and improve the system orbital parameters.
