Empirical limb-darkening coefficients & transit parameters of known exoplanets from TESS

Although the main goal of the Transiting Exoplanet Survey Satellite (\textit{TESS}) is to search for new transiting exoplanets, its data can also be used to study in further detail already known systems. The \textit{TESS} bandpass is particularly interesting to study the limb-darkening effect of the stellar host which is imprinted in transit lightcurves, as the widely used \textsc{phoenix} and \textsc{atlas} stellar models predict different limb-darkening profiles. Here we study this effect by fitting the transit lightcurves of 176 known exoplanetary systems observed by \textit{TESS}, which allows us to extract empirical limb-darkening coefficients (LDCs) for the widely used quadratic law, but also updated transit parameters (including ephemerides refinements) as a byproduct. Comparing our empirically obtained LDCs with theoretical predictions, we find significant offsets when using tabulated \textit{TESS} LDCs. Specifically, the $u_2$ coefficients obtained using \textsc{phoenix} models show the largest discrepancies depending on the method used to derive them, with offsets that can reach up to $\Delta u_2 \approx 0.2$ on average. Most of those average offsets disappear, however, if one uses the SPAM algorithm introduced by Howarth (2011) to calculate the LDCs instead. Our results suggest, however, that for stars cooler than about 5000 K, no methodology is good enough to explain the limb-darkening effect: we observe a sharp deviation between measured and predicted LDCs on both quadratic LDCs of order $\Delta u_1, \Delta u_2 \approx 0.2$ for those cool stars. We recommend caution when assuming limb-darkening coefficients as perfectly known thus, in particular for these cooler stars when analyzing \textit{TESS} transit lightcurves.Comment: 33 pages, 22 figures, 6 tables. Accepted for publication in the Astronomical Journa

Editorial: Introduction to the 2018 ESPEN guidelines on clinical nutrition in the intensive care unit: food for thought and valuable directives for clinicians!

Introduction: The recently published 2018 ESPEN Guidelines on Clinical Nutrition in the Intensive Care Unit [1] represents a valuable revision of the 2006 Enteral Nutrition Guidelines [2] and the 2009 Parenteral Nutrition Guidelines [3] published earlier by this European group. The guidelines committee members have done an excellent job in putting thismanuscript together, providing directives that are clear, concise, brief, and most importantly, transparent. They included only studies published since 2000 for use in their meta-analyses, commenting that this time of transition heralded a new era in the literature involving higher quality randomized control trials (RCTs) and methodologic innovations such as trial registry. Not mentioned (but felt by many within the nutrition community) was the sense that this particular time was a tipping point, following the publication of Van den Berghe’s seminal paper on intensive insulin therapy [4]. Studies published in nutrition prior to this date were felt to reflect an older more antiquated style of management that was less effective. These authors utilized the persistent inflammation catabolism syndrome (PICS) system where four parameters (the patient, intervention, controls, and outcomes) are clearly described, which in turn direct the questions that the guideline committee members were to address. Quality of evidence was assessed by GRADE methodology, and a cut-off date of August 2017 for data entry from the literature was clearly identified. Not all of the recommendations were based on RCTs. The authors are to be commended in that they provided recommendations based on Level 4 low-quality evidence, in areas where RCTs were not available, clearly taking advantage of the group of experts on the committee to provide practical guidance for clinicians where there was a paucity of literature to support evidence-based practices

Protein kinetics and metabolic effects related to disease states in the intensive care unit

Q3Q221S-29SEvaluating protein kinetics in the critically ill population remains a very difficult task. Heterogeneity in the intensive care unit (ICU) population and wide spectrum of disease processes creates complexity in assessing protein kinetics. Traditionally, protein has been delivered in the context of total energy. Focus on energy delivery has recently come into question, as the importance of supplemental protein in patient outcomes has been shown in several recent trials. The ICU patient is prone to catabolism, immobilization, and impaired immunity, which is a perfect storm for massive loss of lean body tissue with a unidirectional flow of amino acids from muscle to immune tissue for immunoglobulin production, as well as liver for gluconeogenesis and acute phase protein synthesis. The understanding of protein metabolism in the ICU has been recently expanded with the discovery of how the mammalian target of rapamycin complex 1 is regulated. The concept of “anabolic resistance” and identifying the quantity of protein required to overcome this resistance is gaining support among critical care nutrition circles. It appears that a minimum of at least 1.2 g/kg/d with levels up to 2.0 g/kg/d of protein or amino acids appears safe for delivery in the ICU setting and may yield a better clinical outcome

Radial velocity survey for planets around young stars (RVSPY)

Aims. We aim to detect planetary companions to young stars with debris disks via the radial velocity method. Methods. We observed HD 114082 during April 2018–August 2022 as one of the targets of our RVSPY program (Radial Velocity Survey for Planets around Young stars). We use the FEROS spectrograph, mounted to the MPG/ESO 2.2 m telescope in Chile, to obtain high signal-to-noise spectra and time series of precise radial velocities (RVs). Additionally, we analyze archival HARPS spectra and TESS photometric data. We use the CERES, CERES++ and SERVAL pipelines to derive RVs and activity indicators and ExoStriker for the independent and combined analysis of the RVs and TESS photometry. Results. We report the discovery of a warm super-Jovian companion around HD 114082 based on a 109.8±0.4 day signal in the combined RV data from FEROS and HARPS, and on one transit event in the TESS photometry. The best-fit model indicates a 8.0±1.0 MJup companion with a radius of 1.00±0.03 RJup in an orbit with a semi-major axis of 0.51±0.01 au and an eccentricity of 0.4±0.04. The companions orbit is in agreement with the known near edge-on debris disk located at ∼28 au. HD 114082 b is possibly the youngest (15±6 Myr), and one of only three young (< 100 Myr) giant planetary companions for which both their mass and radius have been determined observationally. It is probably the first properly model-constraining giant planet that allows distinguishing between hot and cold-start models. It is significantly more compatible with the cold-start model