- ID:
- ivo://CDS.VizieR/J/A+A/527/A8
- Title:
- Transiting planetary system WASP-7
- Short Name:
- J/A+A/527/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first high-precision photometry of the transiting extrasolar planetary system WASP-7, obtained using telescope defocussing techniques and reaching a scatter of 0.68mmag per point. We find that the transit depth is greater and that the host star is more evolved than previously thought. The planet has a significantly larger radius and much lower density and surface gravity than previous measurements showed. Based on the revised properties it is no longer an outlier in planetary mass-radius and period-gravity diagrams. We obtain a more precise transit ephemeris for the WASP-7 system.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/704/1107
- Title:
- Transiting planet candidates in HATNet field 205
- Short Name:
- J/ApJ/704/1107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-8b, a transiting planet with mass M_p_=1.52^+0.18^_-0.16_M_J_, radius R_p_=1.50^+0.08^_-0.06_R_J_, and photometric period P=3.076days. HAT-P-8b has a somewhat inflated radius for its mass, and a somewhat large mass for its period. The host star is a solar-metallicity F dwarf, with mass M_*_=1.28+/-0.04M_{sun}_ and R_*_=1.58^+0.08^_-0.06R_{sun}_. HAT-P-8b was initially identified as one of the 32 transiting-planet candidates in HATNet field G205. We describe the procedures that we have used to follow up these candidates with spectroscopic and photometric observations, and we present a status report on our interpretation for 28 of the candidates. Eight are eclipsing binaries with orbital solutions whose periods are consistent with their photometric ephemerides; two of these spectroscopic orbits are single-lined and six are double-lined.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/485/871
- Title:
- Transiting planet HD 17156b
- Short Name:
- J/A+A/485/871
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present B2 photometry of a primary transit of the planet HD 17156b. These observations were obtained using the MEROPE camera of the Mercator 1.2m Belgian Telescope.
- ID:
- ivo://CDS.VizieR/J/A+A/466/743
- Title:
- Transiting planet OGLE-TR-132b
- Short Name:
- J/A+A/466/743
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- OGLE-TR-132b transits a very metal-rich F dwarf about 2000 pc from the Sun, in the Galactic disc towards Carina. It orbits very close to its host star (a=0.03AU) and has an equilibrium temperature of nearly 2000 K. Using rapid-cadence transit photometry from the FORS2 camera on the VLT and SUSI2 on the NTT, and high-resolution spectroscopy with UVES on the VLT, we refine the shape of the transit light curve and the parameters of the system.
- ID:
- ivo://CDS.VizieR/J/AJ/154/224
- Title:
- Transiting planets in young clusters from K2
- Short Name:
- J/AJ/154/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detection of transiting exoplanets around young stars is more difficult than for older systems owing to increased stellar variability. Nine young open cluster planets have been found in the K2 data, but no single analysis pipeline identified all planets. We have developed a transit search pipeline for young stars that uses a transit-shaped notch and quadratic continuum in a 12 or 24 hr window to fit both the stellar variability and the presence of a transit. In addition, for the most rapid rotators (P_rot_<2 days) we model the variability using a linear combination of observed rotations of each star. To maximally exploit our new pipeline, we update the membership for four stellar populations observed by K2 (Upper Scorpius, Pleiades, Hyades, Praesepe) and conduct a uniform search of the members. We identify all known transiting exoplanets in the clusters, 17 eclipsing binaries, one transiting planet candidate orbiting a potential Pleiades member, and three orbiting unlikely members of the young clusters. Limited injection recovery testing on the known planet hosts indicates that for the older Praesepe systems we are sensitive to additional exoplanets as small as 1-2 R_{Earth}_, and for the larger Upper Scorpius planet host (K2-33) our pipeline is sensitive to ~4 R_{Earth}_ transiting planets. The lack of detected multiple systems in the young clusters is consistent with the expected frequency from the original Kepler sample, within our detection limits. With a robust pipeline that detects all known planets in the young clusters, occurrence rate testing at young ages is now possible.
- 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.
