- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1338
- Title:
- Transiting planetary system WASP-17
- Short Name:
- J/MNRAS/426/1338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric observations of four transits in the WASP-17 planetary system, obtained using telescope defocusing techniques and with scatters reaching 0.5mmag per point. Our revised orbital period is 4.0+/-0.6s longer than previous measurements, a difference of 6.6{sigma}, and does not support the published detections of orbital eccentricity in this system. We model the light curves using the JKTEBOP code and calculate the physical properties of the system by recourse to five sets of theoretical stellar model predictions. The resulting planetary radius, Rb=1.932+/-0.052+/-0.010R_Jup_ (statistical and systematic errors, respectively), provides confirmation that WASP-17b is the largest planet currently known. All 14 planets with radii measured to be greater than 1.6R_Jup_are found around comparatively hot (T_eff_>5900K) and massive (M_A_>1.15M_{sun}_) stars. Chromospheric activity indicators are available for eight of these stars, and all imply a low activity level. The planets have small or zero orbital eccentricities, so tidal effects struggle to explain their large radii.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/396/1023
- Title:
- Transiting planetary system WASP-5
- Short Name:
- J/MNRAS/396/1023
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision photometry of two transit events of the extrasolar planetary system WASP-5, obtained with the Danish 1.54m telescope at ESO La Silla. In order to minimise both random and flat-fielding errors, we defocussed the telescope so its point spread function approximated an annulus of diameter 40 pixels (16 arcsec). Data reduction was undertaken using standard aperture photometry plus an algorithm for optimally combining the ensemble of comparison stars. The resulting light curves have point-to- point scatters of 0.50mmag for the first transit and 0.59mmag for the second. We construct detailed signal to noise calculations for defocussed photometry, and apply them to our observations. We model the light curves with the JKTEBOP code and combine the results with tabulated predictions from theoretical stellar evolutionary models to derive the physical properties of the WASP-5 system.
- ID:
- ivo://CDS.VizieR/J/MNRAS/399/287
- Title:
- Transiting planetary system WASP-4
- Short Name:
- J/MNRAS/399/287
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyse light curves of four transits of the Southern hemisphere extrasolar planetary system WASP-4, obtained with a telescope defocussed so the radius of each point spread function was 17 arcsec (44 pixels). This approach minimises both random and systematic errors, allowing us to achieve scatters of between 0.60 and 0.88mmag per observation over complete transit events. The light curves are augmented by published observations and analysed using the JKTEBOP code. The results of this process are combined with theoretical stellar model predictions to derive the physical properties of the WASP-4 system. WASP-4 is now one of the best-quantified transiting extrasolar planetary systems, and significant further progress requires improvements to our understanding of the physical properties of low-mass stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/408/1680
- Title:
- Transiting planetary system WASP-2
- Short Name:
- J/MNRAS/408/1680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision photometry of three transits of the extrasolar planetary system WASP-2, obtained by defocussing the telescope, and achieving point-to-point scatters of between 0.42 and 0.73mmag. These data are modelled using the JKTEBOP code, and taking into account the light from the recently-discovered faint star close to the system. The physical properties of the WASP-2 system are derived using tabulated predictions from five different sets of stellar evolutionary models, allowing both statistical and systematic error bars to be specified. We find the mass and radius of the planet to be M_b_=0.847+/-0.038+/-0.024M_jup_ and R_b_=1.044+/-0.029+/-0.015R_jup_. It has a low equilibrium temperature of 1280+/-21K, in agreement with a recent finding that it does not have an atmospheric temperature inversion.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/707/167
- Title:
- Transiting planetary system WASP-18
- Short Name:
- J/ApJ/707/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocussing we achieve a photometric precision of 0.47 to 0.83mmag per observation over complete transit events. The data are analysed using the JKTEBOP code and three different sets of stellar evolutionary models. We point out that seven of the nine known massive transiting planets have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.
- 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.
22368. Transiting planet GJ 1132
- 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.
22369. Transiting planet HD 17156b
- 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.
