- ID:
- ivo://CDS.VizieR/J/ApJ/745/58
- Title:
- Light curves of the PMS eclipsing binary Par 1802
- Short Name:
- J/ApJ/745/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Parenago 1802, a member of the ~1 Myr Orion Nebula Cluster, is a double-lined, detached eclipsing binary in a 4.674 day orbit, with equal-mass components (M_2_/M_1_=0.985+/-0.029). Here we present extensive VI_C_JHK_S_light curves (LCs) spanning ~15 yr, as well as a Keck/High Resolution Echelle Spectrometer (HIRES) optical spectrum. The LCs evince a third light source that is variable with a period of 0.73 days, and is also manifested in the high-resolution spectrum, strongly indicating the presence of a third star in the system, probably a rapidly rotating Classical T Tauri star. We incorporate this third light into our radial velocity and LC modeling of the eclipsing pair, measuring accurate masses (M_1_=0.391+/-0.032 and M_2_=0.385+/-0.032M_{sun}_), radii (R_1_=1.73+/-0.02 and R_2_=1.62+/-0.02R_{sun}_), and temperature ratio (T_eff,1_/T_eff,2_=1.0924+/-0.0017). Thus, the radii of the eclipsing stars differ by 6.9%+/-0.8%, the temperatures differ by 9.2%+/-0.2%, and consequently the luminosities differ by 62%+/-3%, despite having masses equal to within 3%. This could be indicative of an age difference of ~3x10^5^yr between the two eclipsing stars, perhaps a vestige of the binary formation history. We find that the eclipsing pair is in an orbit that has not yet fully circularized, e=0.0166+/-0.003. In addition, we measure the rotation rate of the eclipsing stars to be 4.629+/-0.006 days; they rotate slightly faster than their 4.674 day orbit. The non-zero eccentricity and super-synchronous rotation suggest that the eclipsing pair should be tidally interacting, so we calculate the tidal history of the system according to different tidal evolution theories. We find that tidal heating effects can explain the observed luminosity difference of the eclipsing pair, providing an alternative to the previously suggested age difference.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/485/5168
- Title:
- Light curves of WASP-74
- Short Name:
- J/MNRAS/485/5168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present broad-band photometry of 11 planetary transits of the hot Jupiter WASP-74 b, using three medium-class telescopes and employing the telescope-defocusing technique. Most of the transits were monitored through I filters and one was simultaneously observed in five optical (U, g', r', i', z') and three near-infrared (J, H, K) passbands, for a total of 18 light curves. We also obtained new high-resolution spectra of the host star. We used these new data to review the orbital and physical properties of the WASP-74 planetary system. We were able to better constrain the main system characteristics, measuring smaller radius and mass for both the hot Jupiter and its host star than previously reported in the literature. Joining our optical data with those taken with the HST in the near infrared, we built up an observational transmission spectrum of the planet, which suggests the presence of strong optical absorbers, as TiO and VO gases, in its atmosphere.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/843
- Title:
- Light curves of WASP-52
- Short Name:
- J/MNRAS/465/843
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 13 high-precision light curves of eight transits of the exoplanet WASP-52 b, obtained by using four medium-class telescopes, through different filters, and adopting the defocussing technique. One transit was recorded simultaneously from two different observatories and another one from the same site but with two different instruments, including a multiband camera. Anomalies were clearly detected in five light curves and modelled as star-spots occulted by the planet during the transit events. We fitted the clean light curves with the JKTEBOP code, and those with the anomalies with the PRISM+gemc codes in order to simultaneously model the photometric parameters of the transits and the position, size and contrast of each star-spot. We used these new light curves and some from the literature to revise the physical properties of the WASP-52 system. Star-spots with similar characteristics were detected in four transits over a period of 43 d. In the hypothesis that we are dealing with the same star-spot, periodically occulted by the transiting planet, we estimated the projected orbital obliquity of WASP-52 b to be {lambda}=3.8+/-8.4{deg}. We also determined the true orbital obliquity, {psi}=20+/-50{deg}, which is, although very uncertain, the first measurement of {psi} purely from star-spot crossings. We finally assembled an optical transmission spectrum of the planet and searched for variations of its radius as a function of wavelength. Our analysis suggests a flat transmission spectrum within the experimental uncertainties.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A30
- Title:
- Light curves of WASP-3b
- Short Name:
- J/A+A/549/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The TASTE project is searching for low-mass planets with the transit timing variation (TTV) technique by gathering high-precision, short-cadence light curves for a selected sample of transiting exoplanets. It has been claimed that the "hot Jupiter" WASP-3b could be perturbed by a second planet. Presenting eleven new light curves (secured at the IAC80 and UDEM telescopes) and re-analyzing thirty-eight archival light curves in a homogeneous way, we show that new data do not confirm the previously claimed TTV signal. However, we bring evidence that measurements are not consistent with a constant orbital period, though no significant periodicity can be detected. Additional dynamical modeling and follow-up observations are planned to constrain the properties of the perturber or to put upper limits to it. We provide a refined ephemeris for WASP-3b and improved orbital/physical parameters. A contact eclipsing binary, serendipitously discovered among field stars, is reported here for the first time.
- ID:
- ivo://CDS.VizieR/J/A+A/568/A127
- Title:
- Light curves of WASP-67 transit events
- Short Name:
- J/A+A/568/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. The lack of the second and third contact points in this planetary system makes it difficult to obtain accurate measurements of its physical parameters. Aims. By using new high-precision photometric data, we confirm that WASP-67 b shows grazing eclipses and compute accurate estimates of the physical properties of the planet and its parent star. Methods. We present high-quality, multi-colour, broad-band photometric observations comprising five light curves covering two transit events, obtained using two medium-class telescopes and the telescope-defocussing technique. One transit was observed through a Bessel-R filter and the other simultaneously through filters similar to Sloan griz. We modelled these data using jktebop. The physical parameters of the system were obtained from the analysis of these light curves and from published spectroscopic measurements. Results. All five of our light curves satisfy the criterion for being grazing eclipses. We revise the physical parameters of the whole WASP-67 system and, in particular, significantly improve the measurements of the planet's radius and density as compared to the values in the discovery paper. The transit ephemeris was also substantially refined. We investigated the variation of the planet's radius as a function of the wavelength, using the simultaneous multi-band data, finding that our measurements are consistent with a flat spectrum to within the experimental uncertainties.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A126
- Title:
- Light curves of WASP-80 transit events
- Short Name:
- J/A+A/562/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously using two defocussed telescopes. These data were taken through the Bessell I, Sloan g'r'i'z' and near-infrared JHK passbands. We use our data to search for opacity-induced changes in the planetary radius, but find that all values agree with each other. Our data are therefore consistent with a flat transmission spectrum to within the observational uncertainties. We also measure an activity index of the host star of logR'_HK=-4.495, meaning that WASP-80A shows strong chromospheric activity. The non-detection of starspots implies that, if they exist, they must be small and symmetrically distributed on the stellar surface. We model all available optical transit light curves and obtain improved physical properties and orbital ephemerides for the system.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A81
- Title:
- Line list and abundances of the binary zet2 Ret
- Short Name:
- J/A+A/588/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore condensation temperature Tc trends in the binary system zet1 Ret - zet2 Ret, to determine whether there is a depletion of refractories, which could be related to the planet formation process. The star zet2 Ret hosts a debris disk which was detected by an IR excess and confirmed by direct imaging and numerical simulations, while zet1 Ret does not present IR excess nor planets. We derived differential abundances of 24 different species with equivalent widths and spectral synthesis. The star zet1 Ret resulted slightly more metal rich than zet2 Ret by 0.02dex, and the relative abundances showed a positive Tc trend. Then, we propose an scenario in which the refractory elements depleted in zet2 Ret are possibly locked-up in the rocky material that orbits this star and produce the debris disk observed around this object.
- ID:
- ivo://CDS.VizieR/J/ApJ/724/154
- Title:
- Lithium abundances in stars with planets
- Short Name:
- J/ApJ/724/154
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This work presents a homogeneous determination of lithium abundances in a large sample of giant-planet-hosting stars (N=117) and a control sample of disk stars without detected planets (N=145). The lithium abundances were derived using a detailed profile fitting of the LiI doublet at 6708{AA} in LTE. The planet-hosting and comparison stars were chosen to have significant overlap in their respective physical properties, including effective temperatures, luminosities, masses, metallicities, and ages. The combination of uniform data and homogeneous analysis with well-selected samples makes this study well suited to probe for possible differences in the lithium abundances found in planet-hosting stars. An overall comparison between the two samples reveals no obvious differences between stars with and without planets. A closer examination of the behavior of the Li abundances over a narrow range of effective temperature (5700K<=T_eff_<=5850K) indicates subtle differences between the two stellar samples; this temperature range is particularly sensitive to various physical processes that can deplete lithium.
- ID:
- ivo://CDS.VizieR/J/ApJ/855/115
- Title:
- Lithium abundances of KOIs from CKS spectra
- Short Name:
- J/ApJ/855/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The lithium doublet at 6708{AA} provides an age diagnostic for main sequence FGK dwarfs. We measured the abundance of lithium in 1305 stars with detected transiting planets from the Kepler mission using high-resolution spectroscopy. Our catalog of lithium measurements from this sample has a range of abundance from A(Li)=3.11+/-0.07 to an upper limit of -0.84dex. For a magnitude-limited sample that comprises 960 of the 1305 stars, our Keck-HIRES spectra have a median signal-to-noise ratio of 45 per pixel at ~6700{AA} with spectral resolution {lambda}/{Delta}{lambda}=R=55000. We identify 80 young stars that have A(Li) values greater than the Hyades at their respective effective temperatures; these stars are younger than ~650Myr, the approximate age of the Hyades. We then compare the distribution of A(Li) with planet size, multiplicity, orbital period, and insolation flux. We find larger planets preferentially in younger systems, with an A-D two-sided test p-value=0.002, a>3{sigma} confidence that the older and younger planet samples do not come from the same parent distribution. This is consistent with planet inflation/photoevaporation at early ages. The other planet parameters (Kepler planet multiplicity, orbital period, and insolation flux) are uncorrelated with age.
- ID:
- ivo://CDS.VizieR/J/A+A/326/780
- Title:
- Lithium depletion in CABs
- Short Name:
- J/A+A/326/780
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We included 2 tables containing photometric data, together equivalent width of LiI6708 A, for a sample of dwarf components of Chromospherically Active Binaries (CABs).
