80 research outputs found

    A service evaluation of phased- and stepped-care psychological support for health and social care workers during the COVID-19 pandemic

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    BACKGROUND: The COVID-19 pandemic has disproportionally affected the mental health of health and social care workers (HSCWs), with many experiencing symptoms of depression, anxiety and post-traumatic stress disorder. Psychological interventions have been offered via mental health services and in-house psychology teams, but their effectiveness in this context is not well documented. AIMS: To evaluate a stepped-care psychological support pathway for HSCWs from Homerton Healthcare Foundation Trust in London, which offered psychological first aid, evidence-based psychological therapies and group-based well-being workshops. METHOD: The service evaluation used a pre-post approach to assess depression, anxiety, functional impairment and post-traumatic stress disorder symptom change for those who attended sessions of psychological first aid, low- or high-intensity cognitive-behavioural therapy or a combination of these. In addition, the acceptability of the psychological first aid sessions and well-being workshops was explored via feedback data. RESULTS: Across all interventions, statistically significant reductions of depression (d = 1.33), anxiety (d = 1.37) and functional impairment (d = 0.93) were observed, and these reductions were equivalent between the interventions, as well as the demographic and occupational differences between the HSCWs (ethnicity, staff group and redeployment status). HSCWs were highly satisfied with the psychological first aid and well-being workshops. CONCLUSIONS: The evaluation supports the utility of evidence-based interventions delivered as part of a stepped-care pathway for HSCWs with common mental health problems in the context of the COVID-19 pandemic. Given the novel integration of psychological first aid within the stepped-care model as a step one intervention, replication and further testing in larger-scale studies is warranted

    Detection of carbon monoxide's 4.6 micron fundamental band structure in WASP-39b's atmosphere with JWST NIRSpec G395H

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    Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres and, along with water, is important for discerning the oxygen and therefore carbon-to-oxygen ratio of these planets. The fundamental absorption mode of CO has a broad, double-branched structure composed of many individual absorption lines from 4.3 to 5.1 μm, which can now be spectroscopically measured with JWST. Here we present a technique for detecting the rotational sub-band structure of CO at medium resolution with the NIRSpec G395H instrument. We use a single transit observation of the hot Jupiter WASP-39b from the JWST Transiting Exoplanet Community Early Release Science (JTEC ERS) program at the native resolution of the instrument (R ~ 2700) to resolve the CO absorption structure. We robustly detect absorption by CO, with an increase in transit depth of 264 ± 68 ppm, in agreement with the predicted CO contribution from the best-fit model at low resolution. This detection confirms our theoretical expectations that CO is the dominant carbon-bearing molecule in WASP-39b's atmosphere and further supports the conclusions of low C/O and supersolar metallicities presented in the JTEC ERS papers for WASP-39b

    Discovery and characterisation of two Neptune-mass planets orbiting HD 212729 with TESS

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    We report the discovery of two exoplanets orbiting around HD 212729 (TOI\,1052, TIC 317060587), a Teff=6146T_{\rm eff}=6146K star with V=9.51 observed by TESS in Sectors 1 and 13. One exoplanet, TOI-1052b, is Neptune-mass and transits the star, and an additional planet TOI-1052c is observed in radial velocities but not seen to transit. We confirm the planetary nature of TOI-1052b using precise radial velocity observations from HARPS and determined its parameters in a joint RV and photometry analysis. TOI-1052b has a radius of 2.870.24+0.292.87^{+0.29}_{-0.24} R_{\oplus}, a mass of 16.9±1.716.9\pm 1.7 M_{\oplus}, and an orbital period of 9.14 days. TOI-1052c does not show any transits in the TESS data, and has a minimum mass of 34.33.7+4.134.3^{+4.1}_{-3.7} M_{\oplus} and an orbital period of 35.8 days, placing it just interior to the 4:1 mean motion resonance. Both planets are best fit by relatively high but only marginally significant eccentricities of 0.180.07+0.090.18^{+0.09}_{-0.07} for planet b and 0.240.08+0.090.24^{+0.09}_{-0.08} for planet c. We perform a dynamical analysis and internal structure model of the planets as well as deriving stellar parameters and chemical abundances. The mean density of TOI-1052b is 3.91.3+1.73.9^{+1.7}_{-1.3} g cm3^{-3} consistent with an internal structure similar to Neptune. A nearby star is observed in Gaia DR3 with the same distance and proper motion as TOI-1052, at a sky projected separation of ~1500AU, making this a potential wide binary star system.Comment: Accepted to MNRAS. 11 page

    TESS spots a mini-neptune interior to a hot saturn in the TOI-2000 system

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    Hot jupiters (P 60 M\mathrm{M}_\oplus) are almost always found alone around their stars, but four out of hundreds known have inner companion planets. These rare companions allow us to constrain the hot jupiter's formation history by ruling out high-eccentricity tidal migration. Less is known about inner companions to hot Saturn-mass planets. We report here the discovery of the TOI-2000 system, which features a hot Saturn-mass planet with a smaller inner companion. The mini-neptune TOI-2000 b (2.70±0.15R2.70 \pm 0.15 \,\mathrm{R}_\oplus, 11.0±2.4M11.0 \pm 2.4 \,\mathrm{M}_\oplus) is in a 3.10-day orbit, and the hot saturn TOI-2000 c (8.140.30+0.31R8.14^{+0.31}_{-0.30} \,\mathrm{R}_\oplus, 81.74.6+4.7M81.7^{+4.7}_{-4.6} \,\mathrm{M}_\oplus) is in a 9.13-day orbit. Both planets transit their host star TOI-2000 (TIC 371188886, V = 10.98, TESS magnitude = 10.36), a metal-rich ([Fe/H] = 0.4390.043+0.0410.439^{+0.041}_{-0.043}) G dwarf 174 pc away. TESS observed the two planets in sectors 9-11 and 36-38, and we followed up with ground-based photometry, spectroscopy, and speckle imaging. Radial velocities from CHIRON, FEROS, and HARPS allowed us to confirm both planets by direct mass measurement. In addition, we demonstrate constraining planetary and stellar parameters with MIST stellar evolutionary tracks through Hamiltonian Monte Carlo under the PyMC framework, achieving higher sampling efficiency and shorter run time compared to traditional Markov chain Monte Carlo. Having the brightest host star in the V band among similar systems, TOI-2000 b and c are superb candidates for atmospheric characterization by the JWST, which can potentially distinguish whether they formed together or TOI-2000 c swept along material during migration to form TOI-2000 b.Comment: v3 adds RV frequency analysis; 25 pages, 11 figures, 14 tables; revision submitted to MNRAS; machine-readable tables available as ancillary files; posterior samples available from Zenodo at https://doi.org/10.5281/zenodo.7683293 and source code at https://doi.org/10.5281/zenodo.798826

    Photochemically-produced SO2_2 in the atmosphere of WASP-39b

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    Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been detected in exoplanet atmospheres to date. Recent observations from the JWST Transiting Exoplanet Early Release Science Program found a spectral absorption feature at 4.05 μ\mum arising from SO2_2 in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ_J) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of \sim1100 K. The most plausible way of generating SO2_2 in such an atmosphere is through photochemical processes. Here we show that the SO2_2 distribution computed by a suite of photochemical models robustly explains the 4.05 μ\mum spectral feature identified by JWST transmission observations with NIRSpec PRISM (2.7σ\sigma) and G395H (4.5σ\sigma). SO2_2 is produced by successive oxidation of sulphur radicals freed when hydrogen sulphide (H2_2S) is destroyed. The sensitivity of the SO2_2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of \sim10×\times solar. We further point out that SO2_2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations.Comment: 39 pages, 14 figures, accepted to be published in Natur

    Photochemically produced SO2 in the atmosphere of WASP-39b

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    Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability1. However, no unambiguous photochemical products have been detected in exoplanet atmospheres so far. Recent observations from the JWST Transiting Exoplanet Community Early Release Science Program2,3 found a spectral absorption feature at 4.05 μm arising from sulfur dioxide (SO2) in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of around 1,100 K (ref. 4). The most plausible way of generating SO2 in such an atmosphere is through photochemical processes5,6. Here we show that the SO2 distribution computed by a suite of photochemical models robustly explains the 4.05-μm spectral feature identified by JWST transmission observations7 with NIRSpec PRISM (2.7σ)8 and G395H (4.5σ)9. SO2 is produced by successive oxidation of sulfur radicals freed when hydrogen sulfide (H2S) is destroyed. The sensitivity of the SO2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of about 10× solar. We further point out that SO2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations

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

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    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 and Spitzer Space Telescopes. 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 analysis. Here we present a dayside thermal emission spectrum of the ultra-hot Jupiter WASP-18b obtained with the NIRISS instrument on JWST. The data span 0.85 to 2.85 μ\mum in wavelength at an average resolving power of 400 and exhibit minimal systematics. The spectrum shows three water emission features (at >>6σ\sigma confidence) and evidence for optical opacity, possibly due to H^-, TiO, and VO (combined significance of 3.8σ\sigma). Models that fit the data require a thermal inversion, molecular dissociation as predicted by chemical equilibrium, a solar heavy element abundance (''metallicity'', M/H = 1.030.51+1.11_{-0.51}^{+1.11} ×\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 sub-stellar point that decreases steeply and symmetrically with longitude toward the terminators.Comment: JWST ERS bright star observations. Uploaded to inform JWST Cycle 2 proposals. Manuscript under review. 50 pages, 14 figures, 2 table

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

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    Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems. Access to an exoplanet's chemical inventory requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based and high-resolution ground-based facilities. Here we report the medium-resolution (R\sim600) transmission spectrum of an exoplanet atmosphere between 3-5 μ\mum covering multiple absorption features for the Saturn-mass exoplanet WASP-39b, obtained with JWST NIRSpec G395H. Our observations achieve 1.46x 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_2 (28.5σ\sigma) and H2_2O (21.5σ\sigma), and identify SO2_2 as the source of absorption at 4.1 μ\mum (4.8σ\sigma). Best-fit atmospheric models range between 3 and 10x solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2_2, underscore the importance of characterising the chemistry in exoplanet atmospheres, and showcase NIRSpec G395H as an excellent mode for time series observations over this critical wavelength range.Comment: 44 pages, 11 figures, 3 tables. Resubmitted after revision to Natur

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

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    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 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 that, 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 μ\mum, exhibit minimal systematics, and reveal well-defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous H2_2O in the atmosphere and place an upper limit on the abundance of CH4_4. The otherwise prominent CO2_2 feature at 2.8 μ\mum is largely masked by H2_2O. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100×\times solar (i.e., an enrichment of elements heavier than helium relative to the Sun) and a sub-stellar carbon-to-oxygen (C/O) ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation or disequilibrium processes in the upper atmosphere.Comment: 35 pages, 13 figures, 3 tables, Nature, accepte
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