ABSTRACT
The Transiting Exoplanet Survey Satellite has produced a large number of single-transit event candidates which are being monitored by the Next Generation Transit Survey (NGTS). We observed a ...second epoch for the TIC-231005575 system (Tmag = 12.06 and $T_{\rm eff} = 5500 \pm 85\, \mathrm{ K}$) with NGTS and a third epoch with Las Cumbres Observatory’s telescope in South Africa to constrain the orbital period ($P = 61.777\, \mathrm{ d}$). Subsequent radial velocity measurements with CORALIE revealed the transiting object has a mass of M2 = 0.128 ± 0.003 M⊙, indicating the system is a G-M binary. The radius of the secondary is R2 = 0.154 ± 0.008 R⊙ and is consistent with mesa models of stellar evolution to better than 1σ.
ABSTRACT
We report the discovery of the transiting exoplanet NGTS-12b by the Next Generation Transit Survey (NGTS). The host star, NGTS-12, is a V = 12.38 mag star with an effective temperature of ...Teff = 5690 ± 130 K. NGTS-12b orbits with a period of P = 7.53 d, making it the longest period planet discovered to date by the main NGTS survey. We verify the NGTS transit signal with data extracted from the Transiting Exoplanet Survey Satellite (TESS) full-frame images, and combining the photometry with radial velocity measurements from HARPS and FEROS we determine NGTS-12b to have a mass of 0.208 ± 0.022 MJ and a radius of 1.048 ± 0.032 RJ. NGTS-12b sits on the edge of the Neptunian desert when we take the stellar properties into account, highlighting the importance of considering both the planet and star when studying the desert. The long period of NGTS-12b combined with its low density of just 0.223 ± 0.029 g cm−3 make it an attractive target for atmospheric characterization through transmission spectroscopy with a Transmission Spectroscopy Metric of 89.4.
Abstract
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534,
V
= 10.343,
T
= 9.78) observed in TESS sectors 4 and 5 and one ...transiting the G dwarf K2-329 (EPIC 246193072,
V
= 12.70,
K
= 10.67) observed in K2 campaigns 12 and 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of
and a mass of
M
J
and is in a 3.68 day orbit, while K2-329 b has a radius of
and a mass of
M
J
and is in a 12.46 day orbit. As TOI-954 b is 30 times more irradiated than K2-329 b but more or less the same size, these two planets provide an opportunity to test whether irradiation leads to inflation of Saturn-mass planets and contribute to future comparative studies that explore Saturn-mass planets at contrasting points in their lifetimes.
Transiting planets orbiting bright stars are the most favorable targets for follow-up and characterization. We report the discovery of the transiting hot Jupiter XO-7 b and of a second, massive ...companion on a wide orbit around a circumpolar, bright, and metal-rich G0 dwarf (V = 10.52, , ). We conducted photometric and radial velocity follow-up with a team of amateur and professional astronomers. XO-7 b has a period of days, a mass of , a radius of , a density of , and an equilibrium temperature of . Its large atmospheric scale height and the brightness of the host star make it well suited to atmospheric characterization. The wide-orbit companion is detected as a linear trend in radial velocities with an amplitude of over two years, yielding a minimum mass of 4 ; it could be a planet, a brown dwarf, or a low-mass star. The hot Jupiter orbital parameters and the presence of the wide-orbit companion point toward a high-eccentricity migration for the hot Jupiter. Overall, this system will be valuable to understand the atmospheric properties and migration mechanisms of hot Jupiters and will help constrain the formation and evolution models of gas giant exoplanets.
ABSTRACT
We present the discovery of NGTS J214358.5–380102, an eccentric M-dwarf binary discovered by the Next-Generation Transit Survey (NGTS). The system period of 7.618 d is greater than many ...known eclipsing M-dwarf binary systems. Its orbital eccentricity of $0.323^{+0.0014}_{-0.0037}$ is large relative to the period and semimajor axis of the binary. Global modelling of photometry and radial velocities indicates stellar masses of MA = $0.426 ^{+0.0056}_{-0.0049}$ M⊙, MB = $0.455 ^{+0.0058}_{-0.0052}$ M⊙ and stellar radii RA = $0.461 ^{+0.038}_{-0.025}$ R⊙, RB = $0.411 ^{+0.027}_{-0.039}$ R⊙, respectively. Comparisons with stellar models for low-mass stars show that one star is consistent with model predictions whereas the other is substantially oversized. Spectral analysis of the system suggests a primary of spectral type M3V, consistent with both modelled masses and radii, and with spectral energy distribution fitting of NGTS photometry. As the most eccentric eclipsing M-dwarf binary known, NGTS J214358.5–380102 provides an interesting insight into the strength of tidal effects in the circularization of stellar orbits.
By screening of a collection of 50 000 small-molecule compounds, we recently identified 4-arylazo-3,5-diamino-1H-pyrazoles as a novel group of anti-biofilm agents. Here, we report a SAR study based ...on 60 analogues by examining ways in which the pharmacophore can be further optimized, for example, via substitutions in the aryl ring. The SAR study revealed the very potent anti-biofilm compound 4-(2-(2-fluorophenyl)hydrazineylidene)-5-imino-4,5-dihydro-1H-pyrazol-3-amine (2).
Malnutrition, risk of malnutrition, and risk factors for malnutrition are prevalent among acutely admitted medical patients aged ≥65 years and have significant health-related consequences. ...Consequently, we aimed to investigate the effectiveness of a multidisciplinary and transitional nutritional intervention on health-related quality of life compared with standard care.
The study was a block randomized, observer-blinded clinical trial with two parallel arms. The Intervention Group was offered a multidisciplinary transitional nutritional intervention consisting of dietary counselling and six sub-interventions targeting individually assessed risk factors for malnutrition, while the Control Group received standard care. The inclusion criteria were a Mini Nutritional Assessment Short-Form score ≤11, age ≥65 years, and an acute admittance to the Emergency Department. Outcomes were assessed on admission and 8 and 16 weeks after hospital discharge. The primary outcome was the difference between groups in change in health-related quality of life (assessed by the EuroQol-5D-5L) from baseline to 16 weeks after discharge. The secondary outcomes were difference in intake of energy and protein, well-being, muscle strength, and body weight at all timepoints.
From October 2018 to April 2021, 130 participants were included. Sixteen weeks after discharge, 29% in the Intervention Group and 19% in the Control Group were lost to follow-up. Compliance varied between the sub-interventions targeting nutritional risk factors and was generally low after discharge, ranging from 0 to 61%. No difference was found between groups on change in health-related quality of life or on well-being, muscle strength, and body weight at any timepoint, neither using the intention-to-treat analysis nor the per-protocol analysis. The protein intake was higher in the Intervention Group during hospitalization (1.1 (Standard Deviation (SD) 0.4) vs 0.8 (SD 0.5) g/kg/day, p = 0.0092) and 8 weeks after discharge (1.2 (SD 0.5) vs 0.9 (0.4) g/kg/day, p = 0.0025). The percentual intake of calculated protein requirements (82% (SD 24) vs 61% (SD 32), p = 0.0021), but not of calculated energy requirements (89% (SD 23) vs 80% (SD 37), p = 0.2), was higher in the Intervention Group than in the Control Group during hospitalization. Additionally, the Intervention Group had a significantly higher percentual intake of calculated protein requirements (94% (SD 41) vs 74% (SD 30), p = 0.015) and calculated energy requirements (115% (SD 37) vs 94% (SD 31), p = 0.0070) 8 weeks after discharge. The intake of energy and protein was comparable between the groups 16 weeks after discharge.
We found no effect of a multidisciplinary and transitional nutritional intervention for acutely admitted medical patients aged ≥65 years with malnutrition or risk of malnutrition on our primary outcome, health-related quality of life 16 weeks after discharge. Nor did the intervention affect the secondary outcomes, well-being, muscle strength, and body weight from admission to 8 or 16 weeks after discharge. However, the intervention improved energy and protein intake during hospitalization and 8 weeks after discharge. Low compliance with the intervention after discharge may have compromised the effect of the intervention.
The study is registered at ClinicalTrials.gov (identifier: NCT03741283).
Obeticholic acid (OCA) and elafibranor (ELA) are selective and potent agonists for the farnesoid X receptor (FXR) and dual peroxisome proliferator-activated receptor α/δ (PPAR-α/δ), respectively. ...Both agents have demonstrated clinical efficacy in nonalcoholic steatohepatitis (NASH). The present study used OCA and ELA to compare the effects of mono- and combination therapies on metabolic and histological endpoints in Lep
mice with established diet-induced and biopsy-confirmed NASH (ob/ob-NASH). ob/ob-NASH mice were fed the AMLN diet high in trans-fat, fructose and cholesterol for 15 weeks, whereafter they received vehicle, OCA (30 mg/kg, PO, QD), ELA (3, 10 mg/kg, PO, QD), or combinations (OCA + ELA) for eight weeks. Within-subject comparisons were performed on histomorphometric changes, including fractional area of liver fat, galectin-3 and Col1a1. OCA and ELA monotherapies improved all quantitative histopathological parameters and OCA + ELA combinations exerted additive effects on metabolic and histological endpoints. In agreement with their different molecular mechanisms of action, OCA and ELA monotherapies elicited distinct hepatic gene expression profiles and their combination led to profound transcriptome changes associated with further improvements in lipid handling and insulin signaling, suppression of immune responses and reduced extracellular matrix formation. In conclusion, these findings provide preclinical proof-of-concept for combined FXR and PPAR-α/δ agonist-based therapies in NASH.
We report the discovery of two intermediate-mass transiting brown dwarfs (BDs), TOI-569b and TOI-1406b, from NASA's Transiting Exoplanet Survey Satellite mission. TOI-569b has an orbital period of P ...= 6.55604 0.00016 days, a mass of Mb = 64.1 1.9 , and a radius of Rb = 0.75 0.02 . Its host star, TOI-569, has a mass of M = 1.21 0.05 , a radius of R = 1.47 0.03 , dex, and an effective temperature of Teff = 5768 110 K. TOI-1406b has an orbital period of P = 10.57415 0.00063 days, a mass of Mb = 46.0 2.7 , and a radius of Rb = 0.86 0.03 . The host star for this BD has a mass of M = 1.18 0.09 , a radius of R = 1.35 0.03 , dex, and an effective temperature of Teff = 6290 100 K. Both BDs are in circular orbits around their host stars and are older than 3 Gyr based on stellar isochrone models of the stars. TOI-569 is one of two slightly evolved stars known to host a transiting BD (the other being KOI-415). TOI-1406b is one of three known transiting BDs to occupy the mass range of 40-50 and one of two to have a circular orbit at a period near 10 days (with the first being KOI-205b). Both BDs have reliable ages from stellar isochrones, in addition to their well-constrained masses and radii, making them particularly valuable as tests for substellar isochrones in the BD mass-radius diagram.
The Next Generation Transit Survey (NGTS) Wheatley, Peter J; West, Richard G; Goad, Michael R ...
Monthly notices of the Royal Astronomical Society,
04/2018, Letnik:
475, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Abstract
We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars. NGTS builds on the legacy of previous ...surveys, most notably WASP, and is designed to achieve higher photometric precision and hence find smaller planets than have previously been detected from the ground. It also operates in red light, maximizing sensitivity to late K and early M dwarf stars. The survey specifications call for photometric precision of 0.1 per cent in red light over an instantaneous field of view of 100 deg2, enabling the detection of Neptune-sized exoplanets around Sun-like stars and super-Earths around M dwarfs. The survey is carried out with a purpose-built facility at Cerro Paranal, Chile, which is the premier site of the European Southern Observatory (ESO). An array of twelve 20 cm f/2.8 telescopes fitted with back-illuminated deep-depletion CCD cameras is used to survey fields intensively at intermediate Galactic latitudes. The instrument is also ideally suited to ground-based photometric follow-up of exoplanet candidates from space telescopes such as TESS, Gaia and PLATO. We present observations that combine precise autoguiding and the superb observing conditions at Paranal to provide routine photometric precision of 0.1 per cent in 1 h for stars with I-band magnitudes brighter than 13. We describe the instrument and data analysis methods as well as the status of the survey, which achieved first light in 2015 and began full-survey operations in 2016. NGTS data will be made publicly available through the ESO archive.
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