- ID:
- ivo://CDS.VizieR/J/AJ/153/191
- Title:
- Transiting planet GJ 1132
- Short Name:
- J/AJ/153/191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detecting the atmospheres of low-mass, low-temperature exoplanets is a high-priority goal on the path to ultimately detecting biosignatures in the atmospheres of habitable exoplanets. High-precision HST observations of several super-Earths with equilibrium temperatures below 1000K have to date all resulted in featureless transmission spectra, which have been suggested to be due to high-altitude clouds. We report the detection of an atmospheric feature in the atmosphere of a 1.6M_{Earth}_ exoplanet, GJ 1132 b, with an equilibrium temperature of ~600K and orbiting a nearby M dwarf. We present observations of nine transits of the planet obtained simultaneously in the griz and JHK passbands. We find an average radius of 1.43+/-0.16R_{Earth}_ for the planet, averaged over all the passbands, and a radius of 0.255+/-0.023R_{sun}_ for the star, both of which are significantly greater than previously found. The planet radius can be decomposed into a "surface radius" at ~1.375R_{Earth}_ overlaid by atmospheric features that increase the observed radius in the z and K bands. The z-band radius is 4{sigma} higher than the continuum, suggesting a strong detection of an atmosphere. We deploy a suite of tests to verify the reliability of the transmission spectrum, which are greatly helped by the existence of repeat observations. The large z-band transit depth indicates strong opacity from H_2_O and/or CH_4_ or a hitherto-unconsidered opacity. A surface radius of 1.375+/-0.16R_{Earth}_ allows for a wide range of interior compositions ranging from a nearly Earth-like rocky interior, with ~70% silicate and ~30% Fe, to a substantially H_2_O-rich water world.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/602/A107
- Title:
- 231 transiting planets eccentricity and mass
- Short Name:
- J/A+A/602/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a Bayesian homogeneous determination of the orbital parameters of 231 transiting giant planets (TGPs) that are alone or have distant companions; we employed differential evolution Markov chain Monte Carlo methods to analyse radial-velocity (RV) data from the literature and 782 new high-accuracy RVs obtained with the HARPS-N spectrograph for 45 systems over ~3 years. Our work yields the largest sample of systems with a transiting giant exoplanet and coherently determined orbital, planetary, and stellar parameters. We found that the orbital parameters of TGPs in non-compact planetary systems are clearly shaped by tides raised by their host stars. Indeed, the most eccentric planets have relatively large orbital separations and/or high mass ratios, as expected from the equilibrium tide theory. This feature would be the outcome of planetary migration from highly eccentric orbits excited by planet-planet scattering, Kozai-Lidov perturbations, or secular chaos. The distribution of {alpha}=a/a_R_, where a and a_R_ are the semi-major axis and the Roche limit, for well-determined circular orbits peaks at 2.5; this agrees with expectations from the high-eccentricity migration (HEM), although it might not be limited to this migration scenario. The few planets of our sample with circular orbits and {alpha}>5 values may have migrated through disc-planet interactions instead of HEM. By comparing circularisation times with stellar ages, we found that hot Jupiters with a<0.05au have modified tidal quality factors 10^5^<~Qp<~10^9^, and that stellar Qs>~10^6^-10^7^ are required to explain the presence of eccentric planets at the same orbital distance.
- ID:
- ivo://CDS.VizieR/J/AJ/157/218
- Title:
- Transiting planets near the snow line from Kepler
- Short Name:
- J/AJ/157/218
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive catalog of cool (period P>~2 yr) transiting planet candidates in the 4 yr light curves from the prime Kepler mission. Most of the candidates show only one or two transits and have largely been missed in the original Kepler Object of Interest catalog. Our catalog is based on all known such candidates in the literature, as well as new candidates from the search in this paper, and provides a resource to explore the planet population near the snow line of Sun-like stars. We homogeneously performed pixel-level vetting, stellar characterization with Gaia parallax and archival/Subaru spectroscopy, and light-curve modeling to derive planet parameters and to eliminate stellar binaries. The resulting clean sample consists of 67 planet candidates whose radii are typically constrained to 5%, in which 23 are newly reported. The number of Jupiter-sized candidates (29 with radius r>8 R_{Earth}_) in the sample is consistent with the Doppler occurrence. The smaller candidates are more prevalent (23 with 4<r/R_{Earth}_<8, 15 with r/R_{Earth}_<4) and suggest that long-period Neptune-sized planets are at least as common as the Jupiter-sized ones, although our sample is yet to be corrected for detection completeness. If the sample is assumed to be complete, these numbers imply the occurrence rate of 0.39+/-0.07 planets with 4<r/R_{Earth}_<14 and 2<P/yr<20 per FGK dwarf. The stars hosting candidates with r>4 R_{Earth}_ have systematically higher [Fe/H] than do the Kepler field stars, providing evidence that giant planet-metallicity correlation extends to P>2 yr.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/776
- Title:
- Transiting planets WASP-24, 25 and 26
- Short Name:
- J/MNRAS/444/776
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present time-series photometric observations of thirteen transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 and WASP-26 have been observed with Spitzer, and WASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5 to 1.2mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25-arcmin of WASP-26.
- ID:
- ivo://CDS.VizieR/J/MNRAS/447/711
- Title:
- Transiting planet WASP-103
- Short Name:
- J/MNRAS/447/711
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8s, versus 67.4s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3{sigma}. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/1760
- Title:
- Transiting planet WASP-6b
- Short Name:
- J/MNRAS/450/1760
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present updates to prism, a photometric transit-starspot model, and gemc, a hybrid optimization code combining MCMC and a genetic algorithm. We then present high-precision photometry of four transits in the WASP-6 planetary system, two of which contain a starspot anomaly. All four transits were modelled using prism and gemc, and the physical properties of the system calculated. We find the mass and radius of the host star to be 0.836+/-0.063M_{sun}_ and 0.864+/-0.024R_{sun}_, respectively. For the planet, we find a mass of 0.485+/-0.027M_Jup_, a radius of 1.230+/-0.035R_Jup_ and a density of 0.244+/-0.014{rho}_Jup_. These values are consistent with those found in the literature. In the likely hypothesis that the two spot anomalies are caused by the same starspot or starspot complex, we measure the stars rotation period and velocity to be 23.80+/-0.15d and 1.78+/-0.20km/s, respectively, at a colatitude of 75.8{deg}. We find that the sky-projected angle between the stellar spin axis and the planetary orbital axis is {lambda}=7.2{deg}+/-3.7{deg}, indicating axial alignment. Our results are consistent with and more precise than published spectroscopic measurements of the Rossiter-McLaughlin effect. These results suggest that WASP-6 b formed at a much greater distance from its host star and suffered orbital decay through tidal interactions with the protoplanetary disc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/966
- Title:
- Transiting planet WASP-50b
- Short Name:
- J/MNRAS/431/966
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric observations of two transits in the WASP-50 planetary system, obtained using the ESO New Technology Telescope and the defocused-photometry technique. The rms scatters for the two data sets are 258 and 211 ppm with a cadence of 170-200s, setting a new record for ground-based photometric observations of a point source. The data were modelled and fitted using the prism and gemc codes, and the physical properties of the system calculated. We find the mass and radius of the hot star to be 0.861+/-0.057M{sun} and 0.855+/-0.019R{sun}, respectively. For the planet we find a mass of 1.437+/-0.068M_Jup_, a radius of 1.138+/-0.026R_Jup_ and a density of 0.911+/-0.033{rho}Jup. These values are consistent with but more precise than those found in the literature. We also obtain a new orbital ephemeris for the system: T_0_= BJD/TDB 2455558.61237(20)+1.9550938(13)xE.
- ID:
- ivo://CDS.VizieR/J/MNRAS/490/4230
- Title:
- Transiting planet WASP-4b
- Short Name:
- J/MNRAS/490/4230
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transits in the planetary system WASP-4 were recently found to occur 80s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that confirm the existence of transit timing variations, and are well fitted by a quadratic ephemeris with period decay dP/dt=-9.2+/-1.1ms/yr. We rule out instrumental issues, stellar activity and the Applegate mechanism as possible causes. The light-time effect is also not favoured due to the non-detection of changes in the systemic velocity. Orbital decay and apsidal precession are plausible but unproven. WASP-4b is only the third hot Jupiter known to show transit timing variations to high confidence. We discuss a variety of observations of this and other planetary systems that would be useful in improving our understanding of WASP-4 in particular and orbital decay in general.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/3671
- Title:
- Transiting planet WASP-19b
- Short Name:
- J/MNRAS/428/3671
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed a new model for analysing light curves of planetary transits when there are starspots on the stellar disc. Because the parameter space contains a profusion of local minima we developed a new optimization algorithm which combines the global minimization power of a genetic algorithm and the Bayesian statistical analysis of the Markov chain. With these tools we modelled three transit light curves of WASP-19. Two light curves were obtained on consecutive nights and contain anomalies which we confirm as being due to the same spot. Using these data we measure the star's rotation period and velocity to be 11.76+/-0.09d and 3.88+/-0.15km/s, respectively, at a latitude of 65{deg}. We find that the sky-projected angle between the stellar spin axis and the planetary orbital axis is {lambda} =1.0+/-1.2{deg}, indicating axial alignment. Our results are consistent with and more precise than published spectroscopic measurements of the Rossiter-McLaughlin effect.
- ID:
- ivo://CDS.VizieR/J/ApJ/712/925
- Title:
- Transition circumstellar disks in Ophiuchus
- Short Name:
- J/ApJ/712/925
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained millimeter-wavelength photometry, high-resolution optical spectroscopy, and adaptive optics near-infrared imaging for a sample of 26 Spitzer-selected transition circumstellar disks. All of our targets are located in the Ophiuchus molecular cloud (d~125pc) and have spectral energy distributions (SEDs) suggesting the presence of inner opacity holes. We use these ground-based data to estimate the disk mass, multiplicity, and accretion rate for each object in our sample in order to investigate the mechanisms potentially responsible for their inner holes. We find that transition disks are a heterogeneous group of objects, with disk masses ranging from <0.6 to 40M_JUP_ and accretion rates ranging from <10^-11^ to 10^-7^M_{sun}_/yr, but most tend to have much lower masses and accretion rates than "full disks" (i.e., disks without opacity holes). Eight of our targets have stellar companions: six of them are binaries and the other two are triple systems. In four cases, the stellar companions are close enough to suspect they are responsible for the inferred inner holes. We find that nine of our 26 targets have low disk mass (<2.5M_JUP_) and negligible accretion (<10^-11^M_{sun}_/yr), and are thus consistent with photoevaporating (or photoevaporated) disks. Four of these nine non-accreting objects have fractional disk luminosities <10^-3^ and could already be in a debris disk stage. Seventeen of our transition disks are accreting. Thirteen of these accreting objects are consistent with grain growth. The remaining four accreting objects have SEDs suggesting the presence of sharp inner holes, and thus are excellent candidates for harboring giant planets.
