- ID:
- ivo://CDS.VizieR/J/A+A/610/A63
- Title:
- WASP-151b, WASP-153b, WASP-156b
- Short Name:
- J/A+A/610/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of three transiting exoplanets by the SuperWASP survey and the SOPHIE spectrograph with mass and radius determined with a precision better than 15%. WASP-151b and WASP-153b are two hot Saturns with masses, radii, densities and equilibrium temperatures of 0.31^+0.04^_-0.03_M_J_, 1.13^+0.03^_-0.03_R_J_, 0.22^+0.03^_-0.02_rho_J_ and 1,290^+20^_-10_K, and 0.39^+0.02^_-0.02_M_J_, 1.55^+0.10^_-0.08_R_J_, 0.11^+0.02^_-0.02{rho}_J_ and 1,700^+40^ _-40_K, respectively. Their host stars are early G type stars (with magV ~ 13) and their orbital periods are 4.53 and 3.33 days, respectively. WASP-156b is a Super-Neptune orbiting a K type star (magV = 11.6). It has a mass of 0.128^+0.010^_-0.009_M_J_, a radius of 0.51^+0.02^_ -0.02 R_J_, a density of 1.0^+0.1^_-0.1_{rho}_J_, an equilibrium temperature of 970^+30^_-20_K and an orbital period of 3.83 days.
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322. WASP 95-101 transits
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1982
- Title:
- WASP 95-101 transits
- Short Name:
- J/MNRAS/440/1982
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the transiting exoplanets WASP-95b, WASP-96b, WASP-97b, WASP-98b, WASP-99b, WASP-100b and WASP-101b. All are hot Jupiters with orbital periods in the range 2.1-5.7d, masses of 0.5-2.8M_Jup_ and radii of 1.1-1.4R_Jup_. The orbits of all the planets are compatible with zero eccentricity. WASP-99b produces the shallowest transit yet found by WASP-South, at 0.4 per cent. The host stars are of spectral type F2-G8. Five have metallicities of [Fe/H] from -0.03 to +0.23, while WASP-98 has a metallicity of -0.60, exceptionally low for a star with a transiting exoplanet. Five of the host stars are brighter than V=10.8, which significantly extends the number of bright transiting systems available for follow-up studies. WASP-95 shows a possible rotational modulation at a period of 20.7d. We discuss the completeness of WASP survey techniques by comparing to the HATnet project.
- ID:
- ivo://CDS.VizieR/J/A+A/583/A135
- Title:
- XO-2N and XO-2S spectra
- Short Name:
- J/A+A/583/A135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Binary stars hosting exoplanets are a unique laboratory where chemical tagging can be performed to measure with high accuracy the elemental abundances of both stellar components, with the aim to investigate the formation of planets and their subsequent evolution. Here, we present a high-precision differential abundance analysis of the XO-2 wide stellar binary based on high resolution HARPS-N@TNG spectra. Both components are very similar K-dwarfs and host planets. Since they formed presumably within the same molecular cloud, we expect they should possess the same initial elemental abundances. We investigate if the presence of planets can cause some chemical imprints in the stellar atmospheric abundances. We measure abundances of 25 elements for both stars with a range of condensation temperature T_C_=40-1741K, achieving typical precisions of ~0.07dex. The North component shows abundances in all elements higher by +0.067+/-0.032dex on average, with a mean difference of +0.078dex for elements with T_C_>800K. The significance of the XO-2N abundance difference relative to XO-2S is at the 2{sigma} level for almost all elements. We discuss the possibility that this result could be interpreted as the signature of the ingestion of material by XO-2N or depletion in XO-2S due to locking of heavy elements by the planetary companions. We estimate a mass of several tens of M_{earth}_ in heavy elements. The difference in abundances between XO-2N and XO-2S shows a positive correlation with the condensation temperatures of the elements, with a slope of (4.7+/-0.9)x10^-5^dex/K, which could mean that both components have not formed terrestrial planets, but that first experienced the accretion of rocky core interior to the subsequent giant planets.
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/2024
- Title:
- X-ray-age relation and exoplanet evaporation
- Short Name:
- J/MNRAS/422/2024
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the relationship between coronal X-ray emission and stellar age for late-type stars, and the variation of this relationship with spectral type. We select 717 stars from 13 open clusters and find that the ratio of X-ray to bolometric luminosity during the saturated phase of coronal emission decreases from 10^-3.1^ for late K-dwarfs to 10^-4.3^ for early F-type stars (across the range 0.29<(B-V)_0_<1.41). Our determined saturation timescales vary between 10^7.6^ and 10^8.3^ years, though with no clear trend across the whole FGK range. We apply our X-ray emission - age relations to the investigation of the evaporation history of 121 known transiting exoplanets using a simple energy -limited model of evaporation and taking into consideration Roche lobe effects and different heating/evaporation efficiencies. We confirm that a linear cut-off of the planet distribution in the M^2^/R^3^ versus a^-2^ plane is an expected result of population modification by evaporation and that the known transiting exoplanets display such a cut-off. We find that for an evaporation efficiency of 25 percent we expect around 1 in 5 of the known transiting exoplanets to have lost >10 percent of their mass since formation. In addition we provide estimates of the minimum formation mass for which a planet could be expected to survive for 4Gyrs for a range of stellar and planetary parameters. We emphasise the importance of the earliest periods of a planet's life for its evaporation history with 75 percent expect to occur within the first Gyr. This raises the possibility of using evaporation histories to distinguish different migration mechanisms. For planets with spin-orbit angles available from measurements of the Rossiter-McLaughlin effect no difference is found between the distributions of planets with misaligned orbits and those with aligned orbits. This suggests that dynamical effects accounting for misalignment occur early in the life of a planetary system, although additional data is required to test this.