Abstract
SPECULOOS is a ground-based transit survey consisting of six identical 1 m robotic telescopes. The immediate goal of the project is to detect temperate terrestrial planets transiting nearby ...ultracool dwarfs (late M-dwarf stars and brown dwarfs), which could be amenable for atmospheric research with the next generation of telescopes. Here, we report the developments of the northern counterpart of the project—SPECULOOS Northern Observatory, and present its performance during the first three years of operations from mid-2019 to mid-2022. Currently, the observatory consists of one telescope, which is named Artemis. The Artemis telescope demonstrates remarkable photometric precision, allowing it to be ready to detect new transiting terrestrial exoplanets around ultracool dwarfs. Over the period of the first three years after the installation, we observed 96 objects from the SPECULOOS target list for 6000 hr with a typical photometric precision of 0.5%, and reaching a precision of 0.2% for relatively bright non-variable targets with a typical exposure time of 25 s. Our weather downtime (clouds, high wind speed, high humidity, precipitation and/or high concentration of dust particles in the air) over the period of three years was 30% of overall night time. Our actual downtime is 40% because of additional time loss associated with technical problems.
ABSTRACT
A new generation of observatories is enabling detailed study of exoplanetary atmospheres and the diversity of alien climates, allowing us to seek evidence for extraterrestrial biological and ...geological processes. Now is therefore the time to identify the most unique planets to be characterized with these instruments. In this context, we report on the discovery and validation of TOI-715 b, a $R_{\rm b}=1.55\pm 0.06\rm R_{\oplus }$ planet orbiting its nearby (42 pc) M4 host (TOI-715/TIC 271971130) with a period $P_{\rm b} = 19.288004_{-0.000024}^{+0.000027}$ d. TOI-715 b was first identified by TESS and validated using ground-based photometry, high-resolution imaging and statistical validation. The planet’s orbital period combined with the stellar effective temperature $T_{\rm eff}=3075\pm 75~\rm K$ give this planet an installation $S_{\rm b} = 0.67_{-0.20}^{+0.15}~\rm S_\oplus$, placing it within the most conservative definitions of the habitable zone for rocky planets. TOI-715 b’s radius falls exactly between two measured locations of the M-dwarf radius valley; characterizing its mass and composition will help understand the true nature of the radius valley for low-mass stars. We demonstrate TOI-715 b is amenable for characterization using precise radial velocities and transmission spectroscopy. Additionally, we reveal a second candidate planet in the system, TIC 271971130.02, with a potential orbital period of $P_{02} = 25.60712_{-0.00036}^{+0.00031}$ d and a radius of $R_{02} = 1.066\pm 0.092\, \rm R_{\oplus }$, just inside the outer boundary of the habitable zone, and near a 4:3 orbital period commensurability. Should this second planet be confirmed, it would represent the smallest habitable zone planet discovered by TESS to date.
ABSTRACT
We present the discovery and characterization of an eclipsing binary identified by the Next Generation Transit Survey in the ∼115-Myr-old Blanco 1 open cluster. NGTS J0002−29 comprises three ...M dwarfs: a short-period binary and a companion in a wider orbit. This system is the first well-characterized, low-mass eclipsing binary in Blanco 1. With a low mass ratio, a tertiary companion, and binary components that straddle the fully convective boundary, it is an important benchmark system, and one of only two well-characterized, low-mass eclipsing binaries at this age. We simultaneously model light curves from NGTS, TESS, SPECULOOS, and SAAO, radial velocities from VLT/UVES and Keck/HIRES, and the system’s spectral energy distribution. We find that the binary components travel on circular orbits around their common centre of mass in Porb = 1.098 005 24 ± 0.000 000 38 d, and have masses Mpri = 0.3978 ± 0.0033 M⊙ and Msec = 0.2245 ± 0.0018 M⊙, radii Rpri = 0.4037 ± 0.0048 R⊙ and Rsec = 0.2759 ± 0.0055 R⊙, and effective temperatures $T_{\rm pri}=\mbox{$3372\, ^{+44}_{-37}$}$ K and $T_{\rm sec}=\mbox{$3231\, ^{+38}_{-31}$}$ K. We compare these properties to the predictions of seven stellar evolution models, which typically imply an inflated primary. The system joins a list of 19 well-characterized, low-mass, sub-Gyr, stellar-mass eclipsing binaries, which constitute some of the strongest observational tests of stellar evolution theory at low masses and young ages.
ABSTRACT
In the last decade, a dozen close-in giant planets have been discovered orbiting stars with spectral types ranging from M0 to M4, a mystery since known formation pathways do not predict the ...existence of such systems. Here, we confirm TOI-4860 b, a Jupiter-sized planet orbiting an M4.5 host, a star at the transition between fully and partially convective interiors. First identified with TESS data, we validate the transiting companion’s planetary nature through multicolour photometry from the TRAPPIST-South/North, SPECULOOS, and MuSCAT3 facilities. Our analysis yields a radius of $0.76\pm 0.02~\rm R_{Jup}$ for the planet, a mass of $0.34~\rm M_\odot$ for the star, and an orbital period of $1.52~\rm d$. Using the newly commissioned SPIRIT InGaAs camera at the SPECULOOS-South Observatory, we collect infrared photometry in zYJ that spans the time of secondary eclipse. These observations do not detect a secondary eclipse, placing an upper limit on the brightness of the companion. The planetary nature of the companion is further confirmed through high-resolution spectroscopy obtained with the IRD spectrograph at Subaru Telescope, from which we measure a mass of $0.67\pm 0.14~\rm M_{Jup}$. Based on its overall density, TOI-4860 b appears to be rich in heavy elements, like its host star.
ABSTRACT
The variability induced by precipitable water vapour (PWV) can heavily affect the accuracy of time-series photometric measurements gathered from the ground, especially in the near-infrared. ...We present here a novel method of modelling and mitigating this variability, as well as open-sourcing the developed tool – Umbrella. In this study, we evaluate the extent to which the photometry in three common bandpasses (r′, i′, z′), and SPECULOOS’ primary bandpass (I + z′), are photometrically affected by PWV variability. In this selection of bandpasses, the I + z′ bandpass was found to be most sensitive to PWV variability, followed by z′, i′, and r′. The correction was evaluated on global light curves of nearby late M- and L-type stars observed by SPECULOOS’ Southern Observatory (SSO) with the I + z′ bandpass, using PWV measurements from the LHATPRO and local temperature/humidity sensors. A median reduction in RMS of 1.1 per cent was observed for variability shorter than the expected transit duration for SSO’s targets. On timescales longer than the expected transit duration, where long-term variability may be induced, a median reduction in RMS of 53.8 per cent was observed for the same method of correction.
Abstract
We report on the discovery of a transiting Earth-sized (0.95
R
⊕
) planet around an M3.5 dwarf star at 57 pc, EPIC 249631677. The planet has a period of ∼3.14 days, i.e., ∼
π
, with an ...installation of 7.45 S
⊕
. The detection was made using publicly available data from K2's Campaign 15. We observed three additional transits with SPECULOOS Southern and Northern Observatories, and a stellar spectrum from Keck/HIRES, which allowed us to validate the planetary nature of the signal. The confirmed planet is well suited for comparative terrestrial exoplanetology. While exoplanets transiting ultracool dwarfs present the best opportunity for atmospheric studies of terrestrial exoplanets with the James Webb Space Telescope, those orbiting mid-M dwarfs within 100 pc such as EPIC 249631677b will become increasingly accessible with the next generation of observatories.
Background Health status has become increasingly important as an outcome measure in patients with cardiovascular disease. Poor patient-rated health status has been shown to predict mortality in ...patients with coronary artery disease and heart failure. In patients treated with percutaneous coronary intervention (PCI), we examined whether poor health status predicts 6-year mortality and whether a decline in health status is associated with adverse clinical outcome. Methods Consecutive patients (N = 872) treated with PCI as part of the RESEARCH registry, completed the 36-item Short-Form Health Survey (SF-36) at 1 and 12 months post-PCI. Results The SF-36 domains physical functioning (hazard ratio HR 2.59, 95% CI 1.61-4.16), social functioning (HR 2.76, 95% CI 1.74-4.37), role limitations due to physical functioning (HR 2.45, CI 1.52-3.92), mental health (HR 2.12, 95% CI 1.35-3.31), vitality (HR 1.73, 95% CI 1.09-2.74), bodily pain (HR 2.25, 95% CI 1.43-3.54), and general health (HR 2.46, 95% CI 1.57-3.87) were associated with 6-year mortality. A decline in health status was not related with higher 6-year mortality. Conclusions Health status domains as measured with the SF-36 predicted death at 6-year follow-up in PCI patients treated with drug-eluting stenting, independent of demographic and clinical characteristics. In contrast, a decline in health status between 1 and 12 months post index procedure, as measured with the SF-36, was not associated with 6-year mortality in PCI patients treated with drug-eluting stenting.
The temporary decrease of fine particulate matter (PM(sub 2.5)) concentrations in many parts of the world due to the COVID-19 lockdown spurred discussions on urban air pollution and health. However ...there has been little focus on sub-Saharan Africa, as few African cities have air quality monitors and if they do, these data are often not publicly available. Spatial differentials of changes in PM(sub 2.5) concentrations as a result of COVID also remain largely unstudied. To address this gap, we use a serendipitous mobile air quality monitoring deployment of eight Sensirion SPS 30 sensors on motorbikes in the city of Nairobi starting on 16 March 2020, before a COVID-19 curfew was imposed on 25 March and continuing until 5 May 2020. We developed a random-forest model to estimate
PM(sub 2.5) surfaces for the entire city of Nairobi before and during the COVID-19 curfew. The highest PM(sub 2.5) concentrations during both periods were observed in the poor neighborhoods of Kariobangi, Mathare, Umoja, and Dandora, located to the east of the city center. Changes in PM(sub 2.5) were heterogeneous over space. PM(sub 2.5) concentrations increased during the curfew in rapidly urbanizing, the lower-middle-class neighborhoods of Kahawa, Kasarani, and Ruaraka, likely because residents switched from LPG to biomass fuels due to loss of income. Our results indicate that COVID-19 and policies to address it may have exacerbated existing air pollution inequalities in the city of Nairobi. The quantitative results are preliminary, due to sampling limitations and measurement uncertainties, as the available data came exclusively from low-cost sensors. This research serves to highlight that spatial data that is essential for understanding structural inequalities reflected in uneven air pollution burdens and differential impacts of events like the COVID pandemic. With the help of carefully deployed low cost sensors with improved spatial sampling and at least one reference-quality monitor for calibration, we can collect data that is critical for developing targeted interventions that address environmental injustice in the African context.
Multiple major health organisations recommend the use of extracorporeal membrane oxygenation (ECMO) support for COVID-19-related acute hypoxaemic respiratory failure. However, initial reports of ECMO ...use in patients with COVID-19 described very high mortality and there have been no large, international cohort studies of ECMO for COVID-19 reported to date.
We used data from the Extracorporeal Life Support Organization (ELSO) Registry to characterise the epidemiology, hospital course, and outcomes of patients aged 16 years or older with confirmed COVID-19 who had ECMO support initiated between Jan 16 and May 1, 2020, at 213 hospitals in 36 countries. The primary outcome was in-hospital death in a time-to-event analysis assessed at 90 days after ECMO initiation. We applied a multivariable Cox model to examine whether patient and hospital factors were associated with in-hospital mortality.
Data for 1035 patients with COVID-19 who received ECMO support were included in this study. Of these, 67 (6%) remained hospitalised, 311 (30%) were discharged home or to an acute rehabilitation centre, 101 (10%) were discharged to a long-term acute care centre or unspecified location, 176 (17%) were discharged to another hospital, and 380 (37%) died. The estimated cumulative incidence of in-hospital mortality 90 days after the initiation of ECMO was 37·4% (95% CI 34·4–40·4). Mortality was 39% (380 of 968) in patients with a final disposition of death or hospital discharge. The use of ECMO for circulatory support was independently associated with higher in-hospital mortality (hazard ratio 1·89, 95% CI 1·20–2·97). In the subset of patients with COVID-19 receiving respiratory (venovenous) ECMO and characterised as having acute respiratory distress syndrome, the estimated cumulative incidence of in-hospital mortality 90 days after the initiation of ECMO was 38·0% (95% CI 34·6–41·5).
In patients with COVID-19 who received ECMO, both estimated mortality 90 days after ECMO and mortality in those with a final disposition of death or discharge were less than 40%. These data from 213 hospitals worldwide provide a generalisable estimate of ECMO mortality in the setting of COVID-19.
None.
We report results from the Bipolar Exome (BipEx) collaboration analysis of whole-exome sequencing of 13,933 patients with bipolar disorder (BD) matched with 14,422 controls. We find an excess of ...ultra-rare protein-truncating variants (PTVs) in patients with BD among genes under strong evolutionary constraint in both major BD subtypes. We find enrichment of ultra-rare PTVs within genes implicated from a recent schizophrenia exome meta-analysis (SCHEMA; 24,248 cases and 97,322 controls) and among binding targets of CHD8. Genes implicated from genome-wide association studies (GWASs) of BD, however, are not significantly enriched for ultra-rare PTVs. Combining gene-level results with SCHEMA, AKAP11 emerges as a definitive risk gene (odds ratio (OR) = 7.06, P = 2.83 × 10
). At the protein level, AKAP-11 interacts with GSK3B, the hypothesized target of lithium, a primary treatment for BD. Our results lend support to BD's polygenicity, demonstrating a role for rare coding variation as a significant risk factor in BD etiology.
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