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Direct imaging studies have mainly used low-resolution spectroscopy (R ∼ 20–100) to study the atmospheres of giant exoplanets and brown dwarf companions, but the presence of clouds has often led to degeneracies in the retrieved atmospheric abundances (e.g., carbon-to-oxygen ratio, metallicity). This precludes clear insights into the formation mechanisms of these companions. The Keck Planet Imager and Characterizer (KPIC) uses adaptive optics and single-mode fibers to transport light into NIRSPEC (R ∼ 35,000 in the K band), and aims to address these challenges with high-resolution spectroscopy. Using an atmospheric retrieval framework based on petitRADTRANS, we analyze the KPIC high-resolution spectrum (2.29–2.49 μm) and the archival low-resolution spectrum (1–2.2 μm) of the benchmark brown dwarf HD 4747 B (m = 67.2 ± 1.8 M Jup, a = 10.0 ± 0.2 au, T eff ≈ 1400 K). We find that our measured C/O and metallicity for the companion from the KPIC high-resolution spectrum agree with those of its host star within 1σ–2σ. The retrieved parameters from the K-band high-resolution spectrum are also independent of our choice of cloud model. In contrast, the retrieved parameters from the low-resolution spectrum are highly sensitive to our chosen cloud model. Finally, we detect CO, H2O, and CH4 (volume-mixing ratio of log(CH4) = −4.82 ± 0.23) in this L/T transition companion with the KPIC data. The relative molecular abundances allow us to constrain the degree of chemical disequilibrium in the atmosphere of HD 4747 B, and infer a vertical diffusion coefficient that is at the upper limit predicted from mixing length theory.

The formation and evolution pathway for the directly imaged multiplanetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery. We perform a detailed atmospheric retrieval on HR 8799 c to infer the chemical abundances and abundance ratios using a combination of photometric data along with low- and high-resolution spectroscopic data (R ∼ 20–35,000). We specifically retrieve [C/H], [O/H], and C/O and find them to be 0.55−0.39+0.36 , 0.47−0.32+0.31 , and 0.67−0.15+0.12 at 68% confidence. The superstellar C and O abundances, yet a stellar C/O ratio, reveal a potential formation pathway for HR 8799 c. Planet c, and likely the other gas giant planets in the system, formed early on (likely within ∼1 Myr), followed by further atmospheric enrichment in C and O through the accretion of solids beyond the CO ice line. The enrichment either preceded or took place during the early phase of the inward migration to the current planet locations.

The detection of satellites around extrasolar planets, so called exomoons, remains a largely unexplored territory. In this work, we study the potential of detecting these elusive objects from radial velocity monitoring of self-luminous, directly imaged planets. This technique is now possible thanks to the development of dedicated instruments combining the power of high-resolution spectroscopy and high-contrast imaging. First, we demonstrate a sensitivity to satellites with a mass ratio of 1%–4% at separations similar to the Galilean moons from observations of a brown-dwarf companion (HR 7672 B; K mag = 13; 0.″7 separation) with the Keck Planet Imager and Characterizer (R ∼ 35,000 in the K band) at the W. M. Keck Observatory. Current instrumentation is therefore already sensitive to large unresolved satellites that could be forming from gravitational instability akin to binary star formation. Using end-to-end simulations, we then estimate that future instruments such as the Multi-Object Diffraction-limited High-resolution Infrared Spectrograph, planned for the Thirty Meter Telescope, should be sensitive to satellites with mass ratios of ∼10−4. Such small moons would likely form in a circumplanetary disk similar to the Jovian satellites in the solar system. Looking for the Rossiter–McLaughlin effect could also be an interesting pathway to detecting the smallest moons on short orbital periods. Future exomoon discoveries will allow precise mass measurements of the substellar companions that they orbit and provide key insight into the formation of exoplanets. They would also help constrain the population of habitable Earth-sized moons orbiting gas giants in the habitable zone of their stars.

The 16 Myr old A0V star HD 156623 in the Scorpius–Centaurus association hosts a high-fractional-luminosity debris disk, recently resolved in scattered light for the first time by the Gemini Planet Imager (GPI) in polarized intensity only. We present a new analysis of the GPI H-band polarimetric detection of the HD 156623 debris disk, with particular interest in its unique morphology. This debris disk lacks a visible inner clearing, unlike the majority of low-inclination disks in the GPI sample and in Sco-Cen, and it is known to contain CO gas, positioning it as a candidate “hybrid” or “shielded” disk. We use radiative transfer models to constrain the geometric parameters of the disk based on scattered light data and thermal models to constrain the unresolved inner radius based on the system’s spectral energy distribution (SED). We also compute a measurement of the polarized scattering phase function, adding to the existing sample of empirical phase function measurements. We find that HD 156623's debris disk inner radius is constrained to less than 26.6 au from scattered light imagery and less than 13.4 au from SED modeling at a 99.7% confidence interval and suggest that gas drag may play a role in retaining sub-blowout-size dust grains so close to the star.

We used the Keck Planet Imager and Characterizer to obtain high-resolution (R ∼ 35,000) K-band spectra of κ Andromedae b, a planetary-mass companion orbiting the B9V star, κ Andromedae A. We characterized its spin, radial velocity, and bulk atmospheric parameters through use of a forward-modeling framework to jointly fit planetary spectra and residual starlight speckles, obtaining likelihood-based posterior probabilities. We also detected H2O and CO in its atmosphere via cross correlation. We measured a vsin(i) value for κ Andromedae b of 38.42 ± 0.05 km s−1, allowing us to extend our understanding of the population of close-in bound companions at higher rotation rates. This rotation rate is one of the highest spins relative to breakup velocity measured to date, at close to 50% of breakup velocity. We identify a radial velocity −17.35−0.09+0.05 km s−1, which we use with existing astrometry and radial velocity measurements to update the orbital fit. We also measure an effective temperature of 1700 ± 100 K and a log(g) of 4.7 ± 0.5 cgs dex.

GQ Lup B is one of the few substellar companions with a detected cicumplanetary disk (CPD). Observations of the CPD suggest the presence of a cavity, possibly formed by an exosatellite. Using the Keck Planet Imager and Characterizer (KPIC), a high-contrast imaging suite that feeds a high-resolution spectrograph (1.9–2.5 µm, R∼35,000), we present the first dedicated radial velocity (RV) observations around a high-contrast, directly imaged substellar companion, GQ Lup B, to search for exosatellites. Over 11 epochs, we find a best and median RV error of 400–1000 m s−1, most likely limited by systematic fringing in the spectra due to transmissive optics within KPIC. With this RV precision, KPIC is sensitive to exomoons 0.6%–2.8% the mass of GQ Lup B (∼30 M Jup) at separations between the Roche limit and 65 R Jup, or the extent of the cavity inferred within the CPD detected around GQ Lup B. Using simulations of HISPEC, a high resolution infrared spectrograph planned to debut at W.M. Keck Observatory in 2026, we estimate future exomoon sensitivity to increase by over an order of magnitude, providing sensitivity to less massive satellites potentially formed within the CPD itself. Additionally, we run simulations to estimate the amount of material that different masses of satellites could clear in a CPD to create the observed cavity. We find satellite-to-planet mass ratios of q > 2 × 10−4 can create observable cavities and report a maximum cavity size of ∼51 R Jup carved from a satellite.

The \"South American Research Network for the Surveillance and Control of Insecticide-Resistance in Arthropod Vectors\" (WINSA), established in 2024 by the IRD and FIOCRUZ with support from the US-CDC VecNet initiative and WHO-TDR, aims to coordinate research on insecticide resistance in arthropod vectors in South America, provide a platform for regional collaboration, and develop effective mitigation strategies. WINSA brings together leading technical experts representing research institutions from 14 countries and territories located in South America, the USA, and France to promote collaboration and information exchange, identify research gaps and priorities, enhance technical capacity in insecticide resistance monitoring, and support national and regional programs on vector resistance issues. This network seeks to contribute to the reduction and elimination of vector-borne diseases in South America.

Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μm) VFN demonstrator mode was deployed on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory and presented earlier. In this Letter, we present the first VFN companion detections. Three targets, HIP 21543 Ab, HIP 94666 Ab, and HIP 50319 B, were detected with host–companion flux ratios between 70 and 430 at and within one diffraction beamwidth (λ/D). We complement the spectra from KPIC VFN with flux ratio and position measurements from the CHARA Array to validate the VFN results and provide a more complete characterization of the targets. This Letter reports the first direct detection of these three M dwarf companions, yielding their first spectra and flux ratios. Our observations provide measurements of bulk properties such as effective temperatures, radial velocities, and vsini , and verify the accuracy of the published orbits. These detections corroborate earlier predictions of the KPIC VFN performance, demonstrating that the instrument mode is ready for science observations.

Bolivia has the highest incidence of Chagas disease (CD) worldwide. Caused by the parasite Trypanasoma cruzi , CD is generally a chronic condition. Diagnosis is logistically and financially challenging, requiring at least two different laboratory-based serological tests. Many CD cases are missed; in Bolivia it is estimated just 6% of individuals chronically infected with T . cruzi get diagnosed. Achieving control on the way to elimination of CD requires a radical simplification of the current CD testing pathways, to overcome the barriers to accessing CD treatment. We aimed to generate unbiased performance data of lateral flow assays (LFAs) for T . cruzi infection in Bolivia, to evaluate their usefulness for improving T . cruzi diagnosis rates in a precise and efficient manner. This retrospective, laboratory-based, diagnostic evaluation study sought to estimate the sensitivity/specificity of 10 commercially available LFAs for T . cruzi , using the current CD diagnostic algorithm employed in Bolivia as the reference test method. All tests were blinded at the study site and performed by three operators. In total, 470 serum samples were tested, including 221 and 249 characterized as CD-positive/-negative, respectively. The LFAs were scored according to their relative importance using a decision-tree-based algorithm, with the mean decrease in Gini index as the scoring metric. The estimates of sensitivities ranged from 62.2–97.7% (95% confidence interval (CI) lower bound 55.0–94.7%); for specificities the range was 78.6–100% (95% CI lower bound 72.0–97.5%); 5/10 and 6/10 tests had sensitivity >90% and specificity >95%, respectively. Four LFAs showed high values of both sensitivity (93–95%) and specificity (97–99%). The agreement between 6 LFAs and the reference tests was almost perfect (Kappa 0.83–0.94). Most LFAs evaluated thus showed performances comparable with current laboratory-based diagnostic methods.

Background: Healthcare professionals experience high levels of stress due to demanding work, especially in metropolitan areas. Nature-based interventions offer potential mental health benefits. This randomized intervention study aimed to evaluate the effects of nature immersion therapies on mental health outcomes in healthcare workers with different psychological risk in Bogota, Colombia. Methods: During a period of 6 months, a total of 82 healthcare workers from two institutions were assigned to three groups: two exposed weekly to nature (parks and forests) and one control group with monthly conventional interventions. Psychological assessments of stress, anxiety, fatigue, and sleep quality were conducted at three time points (baseline, three, and six months of intervention). Cortisol Awakening Response (CAR) was measured monthly using immunoassay. Results: A decrease in the proportion of participants reporting high levels of perceived stress was observed in both intervention groups. Both forest and parks interventions significantly reduced anxiety and fatigue, while sleep quality improved only in the forest group. Multivariate analysis found a negative association between fatigue and forest intervention, as well as significant differences in CAR concentrations across groups over time. Conclusions: This study provides evidence that nature immersion therapy, particularly urban forests, positively impact mental and physical health, reducing stress, anxiety, fatigue, and CAR levels, and could be considered as an effective intervention to enhance workers’ resilience to stress, benefiting their overall health and well-being.