A warm Neptune's methane reveals core mass and vigorous atmospheric mixing.

Observations of transiting gas giant exoplanets have revealed a pervasive depletion of methane1,2,3,4, which has only recently been identified atmospherically5,6. The depletion is thought to be maintained by disequilibrium processes such as photochemistry or mixing from a hotter interior7,8,9. However, the interiors are largely unconstrained along with the vertical mixing strength and only upper limits on the CH4 depletion have been available. The warm Neptune WASP-107 b stands out among exoplanets with an unusually low density, reported low core mass10, and temperatures amenable to CH4 though previous observations have yet to find the molecule2,4. Here we present a JWST NIRSpec transmission spectrum of WASP-107 b which shows features from both SO2 and CH4 along with H2O, CO2, and CO. We detect methane with 4.2σ significance at an abundance of 1.0±0.5 ppm, which is depleted by 3 orders of magnitude relative to equilibrium expectations. Our results are highly constraining for the atmosphere and interior, which indicate the envelope has a super-solar metallicity of 43±8× solar, a hot interior with an intrinsic temperature of Tint=460±40 K, and vigorous vertical mixing which depletes CH4 with a diffusion coefficient of Kzz = 1011.6±0.1 cm2/s. Photochemistry has a negligible effect on the CH4 abundance, but is needed to account for the SO2. We infer a core mass of 11.5 - 3.6 + 3.0 M⊕, which is much higher than previous upper limits10, releasing a tension with core-accretion models11.

A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b.

Close-in giant exoplanets with temperatures greater than 2,000 K ('ultra-hot Jupiters') have been the subject of extensive efforts to determine their atmospheric properties using thermal emission measurements from the Hubble Space Telescope (HST) and Spitzer Space Telescope1-3. However, previous studies have yielded inconsistent results because the small sizes of the spectral features and the limited information content of the data resulted in high sensitivity to the varying assumptions made in the treatment of instrument systematics and the atmospheric retrieval analysis3-12. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS13 instrument on the JWST. The data span 0.85 to 2.85 µm in wavelength at an average resolving power of 400 and exhibit minimal systematics. The spectrum shows three water emission features (at >6σ confidence) and evidence for optical opacity, possibly attributable to H-, TiO and VO (combined significance of 3.8σ). Models that fit the data require a thermal inversion, molecular dissociation as predicted by chemical equilibrium, a solar heavy-element abundance ('metallicity', [Formula: see text] times solar) and a carbon-to-oxygen (C/O) ratio less than unity. The data also yield a dayside brightness temperature map, which shows a peak in temperature near the substellar point that decreases steeply and symmetrically with longitude towards the terminators.

Early Release Science of the exoplanet WASP-39b with JWST NIRISS.

The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy1-4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality5-9. Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6-2.8 µm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy-element enhancement ('metallicity') of about 10-30 times the solar value, a sub-solar carbon-to-oxygen (C/O) ratio and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-grey clouds with inhomogeneous coverageof the planet's terminator.

Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H.

Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems1,2. Access to the chemical inventory of an exoplanet requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based3-5 and high-resolution ground-based6-8 facilities. Here we report the medium-resolution (R ≈ 600) transmission spectrum of an exoplanet atmosphere between 3 and 5 µm covering several absorption features for the Saturn-mass exoplanet WASP-39b (ref. 9), obtained with the Near Infrared Spectrograph (NIRSpec) G395H grating of JWST. Our observations achieve 1.46 times photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO2 (28.5σ) and H2O (21.5σ), and identify SO2 as the source of absorption at 4.1 µm (4.8σ). Best-fit atmospheric models range between 3 and 10 times solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterizing the chemistry in exoplanet atmospheres and showcase NIRSpec G395H as an excellent mode for time-series observations over this critical wavelength range10.

Early Release Science of the exoplanet WASP-39b with JWST NIRCam.

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. 1,2) provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution and high precision, which, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0-4.0 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. 3,4,) or disequilibrium processes in the upper atmosphere (for example, refs. 5,6).

Caracteristicas y frecuencia del personal de enfermeria que presenta varices, en servicios de hospitales publicos de Corrientes, Capital / Charactristics and frecuency of nursing staff presenting varicose veins, in public hospital service of Corrientes, Capital

Se realizó el estudio, para determinar lascaracterísticas del personal de Enfermería que presenta Várices en los servicios Emergencia,Terapia Intensiva y Clínica Médica de los hospitales "José Francisco de San Martin"y "Juan Pablo II" . El diseño metodológico utilizadofue de tipo cuantitativo, descriptivo,transversal y observacional.Del total de 150 profesionales que reunieron los criterios de inclusión, exclusión y eliminación,se selecionó a 54 enfermeros;por un muestreo probabilistico sistemático, la recolección de los datos se realizó durante los meses de agosto y septiembre del 2017, a travez de unaencuesta.Se analizaron las variables frecuencia de aparcición de Várices, edad, sexo, tipo de varices, antigüedad en el servicio, tiempo de bipedestacion...

The study was carried out to determine the characteristics of the nursing staff that presents varicose veins in the Emergency, Intensive Care and Medical Clinic services of the "José Francisco de San Martin" and "Juan Pablo II" hospitals. The methodological design used was quantitative, descriptive, prospective, crosssectional and observational. Out of the total of 150 professionals who met the inclusion, exclusion and elimination criteria, 54 nurses were selected, and by a systematic probabilistic sampling, the data collection was carried out during the months of August and September of 2017, through a survey. The variables of varices frequency, age, sex, type of varicose veins, length of service, and standing time were analyzed...

Water vapour absorption in the clear atmosphere of a Neptune-sized exoplanet.

Transmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) planets during transits have revealed only featureless spectra. From this it was concluded that the majority of small, warm planets evolve to sustain atmospheres with high mean molecular weights (little hydrogen), opaque clouds or scattering hazes, reducing our ability to observe the composition of these atmospheres. Here we report observations of the transmission spectrum of the exoplanet HAT-P-11b (which has a radius about four times that of Earth) from the optical wavelength range to the infrared. We detected water vapour absorption at a wavelength of 1.4 micrometres. The amplitude of the water absorption (approximately 250 parts per million) indicates that the planetary atmosphere is predominantly clear down to an altitude corresponding to about 1 millibar, and sufficiently rich in hydrogen to have a large scale height (over which the atmospheric pressure varies by a factor of e). The spectrum is indicative of a planetary atmosphere in which the abundance of heavy elements is no greater than about 700 times the solar value. This is in good agreement with the core-accretion theory of planet formation, in which a gas giant planet acquires its atmosphere by accreting hydrogen-rich gas directly from the protoplanetary nebula onto a large rocky or icy core.