- 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.
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Search Results
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/749/79
- Title:
- Transition disks. II. Southern MoC
- Short Name:
- J/ApJ/749/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition disk objects are pre-main-sequence stars with little or no near-IR excess and significant far-IR excess, implying inner opacity holes in their disks. Here we present a multifrequency study of transition disk candidates located in Lupus I, III, IV, V, VI, Corona Australis, and Scorpius. Complementing the information provided by Spitzer with adaptive optics (AO) imaging (NaCo, VLT), submillimeter photometry (APEX), and echelle spectroscopy (Magellan, Du Pont Telescopes), we estimate the multiplicity, disk mass, and accretion rate for each object in our sample in order to identify the mechanism potentially responsible for its inner hole. We find that our transition disks show a rich diversity in their spectral energy distribution morphology, have disk masses ranging from <~1 to 10M_JUP_, and accretion rates ranging from <~10^-11^ to 10^-7.7^M_{sun}_/yr. Of the 17 bona fide transition disks in our sample, three, nine, three, and two objects are consistent with giant planet formation, grain growth, photoevaporation, and debris disks, respectively. Two disks could be circumbinary, which offers tidal truncation as an alternative origin of the inner hole.
- ID:
- ivo://CDS.VizieR/J/other/ExA/51.109
- Title:
- Transit KELT-11b observed by CHEOPS
- Short Name:
- J/other/ExA/51.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contributions by ten additional ESA Member States. CHEOPS is the first mission dedicated to search for transits of exoplanets using ultrahigh precision photometry on bright stars already known to host planets. As a follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible, existing radii measurements or provide first accurate measurements for a subset of those planets for which the mass has already been estimated from ground-based spectroscopic surveys. The expected photometric precision will also allow CHEOPS to go beyond measuring only transits and to follow phase curves or to search for exo-moons, for example. Finally, by unveiling transiting exoplanets with high potential for in-depth characterisation, CHEOPS will also provide prime targets for future instruments suited to the spectroscopic characterisation of exoplanetary atmospheres. To reach its science objectives, requirements on the photometric precision and stability have been derived for stars with magnitudes ranging from 6 to 12 in the V band. In particular, CHEOPS shall be able to detect Earth-size planets transiting G5 dwarf stars (stellar radius of 0.9R_sun_) in the magnitude range 6<V<9 by achieving a photometric precision of 20 ppm in 6 hours of integration time. In the case of K-type stars (stellar radius of 0.7R_{sun}_) of magnitude in the range 9<V<12, CHEOPS shall be able to detect transiting Neptune-size planets achieving a photometric precision of 85ppm in 3 hours of integration time. This precision has to be maintained over continuous periods of observation for up to 48 hours. This precision and stability will be achieved by using a single, frame-transfer, back-illuminated CCD detector at the focal plane assembly of a 33.5cm diameter, on-axis Ritchey-Chretien telescope. The nearly 275kg spacecraft is nadir-locked, with a pointing accuracy of about 1arcsec rms, and will allow for at least 1Gbit/day downlink. The sun-synchronous dusk-dawn orbit at 700km altitude enables having the Sun permanently on the backside of the spacecraft thus minimising Earth stray light. A mission duration of 3.5 years in orbit is foreseen to enable the execution of the science programme. During this period, 20% of the observing time is available to the wider community through yearly ESA call for proposals, as well as through discretionary time approved by ESA's Director of Science. At the time of this writing, CHEOPS commissioning has been completed and CHEOPS has been shown to fulfill all its requirements. The mission has now started the execution of its science programme.
