Velocity Monitoring Research Articles

Binary star population of the Sculptor dwarf galaxy

Aims. We aim to compute the binary fraction of “classical” dwarf spheroidal galaxies (dSphs) that are satellites of the Milky Way (MW). This value can offer insights into the binary fraction in environments that are less dense and more metal-poor than our own galaxy. Additionally, knowledge of the binary fraction in dwarf galaxies is important with respect to avoiding overestimations of their dark matter content, inferred from stellar kinematics. Methods. We refined an existing method from the literature, placing an emphasis on providing robust uncertainties on the value of the binary fraction. We applied this modified method to a VLT/FLAMES dataset for Sculptor, specifically acquired for the purpose of velocity monitoring of individual stars, as well as to literature datasets for other six MW “classical” dSphs. In all cases, the targeted stars were mainly red giant branch stars, with expected masses of around 0.8 M⊙. The VLT/FLAMES dataset offers the most precise binary fractions compared to literature datasets, due to its time baseline of 12 yr, along with at least nine repeated observations for each star. Results. We found that the binary fraction of Sculptor is 0.55−0.19+0.17. We find that it is important to take into account the Roche lobe overflow for constraining the period distribution of binary stars. In contrast to what has recently been proposed in the literature, our analysis indicates that there is no evidence to support varying the properties of the binary stellar population or their deviations from those established for the solar neighborhood, based on the sample of MW dSphs analyzed here.

Hemoglobin H Disease and Growth: A Comparative Study of DHbH and NDHbH Patients.

Hemoglobin H disease (HbH), a hemoglobinopathy resulting from abnormal alpha globin genes, is classified into two categories: deletional HbH (DHbH) and non-deletional HbH (NDHbH). The alpha-mutation genotypes exhibit a range of clinical anemias, which differentially impact patient growth. This retrospective study assessed the growth of HbH patients at Siriraj Hospital, Mahidol University. Patients diagnosed with HbH between January 2005 and April 2021 were analyzed using growth standard scores of the Thai Society for Pediatric Endocrinology (2022 version) and BMI-for-age Z scores of the World Health Organization. Growth failure was defined as a patient's height for age exceeding two standard deviations below the mean. Of the 145 HbH patients, 75 (51.7%) had NDHbH, with --SEA/αCSα being the most common genotype (70 patients; 93.3%). The mean baseline hemoglobin level was significantly lower in NDHbH patients than in DHbH patients (8.16 ± 0.93 g/dL vs. 9.51 ± 0.68 g/dL; P < 0.001). Splenomegaly and growth failure prevalences were higher in NDHbH patients (37.3% vs. 0%, with P < 0.001, and 22.7% vs. 8.6%, with P = 0.020, respectively). Multivariable analysis revealed splenomegaly > 3 cm was associated with growth failure (OR = 4.28; 95% CI, 1.19-15.39; P = 0.026). NDHbH patients exhibited lower hemoglobin levels and more pronounced splenomegaly than DHbH patients. Growth failure can occur in both HbH types but appears more prevalent in NDHbH. Close monitoring of growth velocity is essential, and early treatment interventions may be required to prevent growth failure.

Controlling refractive index and reducing the Global Warming Potential of Cerenkov gas radiators: a challenge in the era of diminishing fluorocarbon availability

Saturated fluorocarbons (SFCs) of the form CnF(2n+2) are chosen for their optical properties (high transparency in the near UV, adapted refractive index and low chromatic dispersion over wavelength ranges of interest) for use as Cherenkov radiators. The COMPASS and LHCb experiments currently use C4F10 and CF4 gas radiators. SFCs have high Global Warming Potentials (GWPs), however (in the range 5000–9000). There is thus an impetus to reduce their use and wastage through leaks in existing installations.Newer fluids of the form CnF2nO, including the 3M NOVEC® range, can offer similar optical performance to SFCs of the same order, n, but with GWPs equivalent to CO2. These GWPs are, however, geometry-specific: closed molecular rings having an oxygen atom as a link can have GWPs as high as those of SFCs, and should be avoided.While the optical constraints of RICH detectors can motivate a “special case” argument to retain the use of preferred SFCs, legislation and external market forces will limit their future availability, leaving “holes” in the CnFx spectrum that might not be filled by NOVEC equivalents. This situation might require the blending of low molar concentrations of heritage-stock higher-order SFCs and NOVEC vapours with transparent light gases such as nitrogen, and is the subject of this paper.While continuous optical measurement of refractive index in dynamically changing gas mixtures is very demanding, the monitoring of sound velocity has been historically shown to provide simple, reliable and continuous real time mixture information. Indeed the speed of sound is, in itself, a monitor of the speed of light and the Cherenkov threshold in a gas radiator.This ultrasonic (“sonar”) technique was first used for controlling the real-time blending C5F12 with N2 in the SLD CRID at the SLAC linear collider. The technique could become important again in future operation to meet the optical and low GWP constraints of future Cherenkov gas radiators. Some examples are explored in this paper.

Velocity-Based Strength Training: The Validity and Personal Monitoring of Barbell Velocity with the Apple Watch.

Velocity-based training (VBT) is a method to monitor resistance training based on measured kinematics. Often, measurement devices are too expensive for non-professional use. The purpose of this study was to determine the accuracy and precision of the Apple Watch 7 and the Enode Pro device for measuring mean, peak, and propulsive velocity during the free-weighted back squat (in comparison to Vicon as the criterion). Velocity parameters from Vicon optical motion capture and the Apple Watch were derived by processing the motion data in an automated Python workflow. For the mean velocity, the barbell-mounted Apple Watch (r = 0.971-0.979, SEE = 0.049), wrist-worn Apple Watch (r = 0.952-0.965, SEE = 0.064) and barbell-mounted Enode Pro (r = 0.959-0.971, SEE = 0.059) showed an equal level of validity. The barbell-mounted Apple Watch (Vpeak: r = 0.952-0.965, SEE = 0.092; Vprop: r = 0.973-0.981, SEE = 0.05) was found to be the most valid for assessing propulsive and peak lifting velocity. The present results on the validity of the Apple Watch are very promising, and may pave the way for the inclusion of VBT applications in mainstream consumer wearables.

The Ventilation Capacity of Earthen Vernacular Buildings With Timber Projections (Sachnisi) in Dense Urban Canyons – Findings From a Field Study in the Mediterranean

Vernacular architecture employs numerous elements for enhancing natural ventilation, especially in the Mediterranean climate. However, the cooling effectiveness of natural ventilation also relies on occupant behaviour and is highly determined by urban scale attributes. Still, airflow in real, inhomogeneous historic urban settings is rarely integrated in the thermal comfort studies of historic buildings. In this study, a multi-scale approach is adopted in order to assess the role of ventilation in establishing thermal comfort in earthen buildings, in real field conditions. This is achieved by addressing field monitoring of air velocity, temperature and relative humidity in: a) a dense (packing density λp=0.60) and inhomogeneous historic neighbourhood in Nicosia, Cyprus (measurement at a reference height); b) the street-canyon (measured at the mid-height of a narrow canyon with aspect ratio 2); and c) the interior of a typical adobe building with semi-open, pass-through spaces (portico) and closed timber projections with multiple openings, called sachnisi. Building ventilation was addressed as a function of in-street and rooftop airflow. Indoor thermal comfort was assessed in the case of specific ventilation patterns, comparing three adaptive comfort models. The results highlight the complexity of airflow in real inhomogeneous urban canopies and demonstrate that air velocity level in the street canyon is approximately one third of the reference free-stream wind velocity, while indoor air velocity remains at minimum levels. The study also reveals the contribution of night-time ventilation in cooling. Finally, spatial differentials of indoor environmental conditions in the portico were recorded for the first time, demonstrating the role of the sachnisi as a wind-capture element.

Continuous fetal cerebral blood flow monitoring during labor: A feasibility study

BackgroundCurrent methods for fetal surveillance during labor have significant limitations. Since continuous fetal cerebral blood flow velocity (CBFV) monitoring during labor may add valuable information about fetal well-being, we developed a new ultrasound system called VisiBeam. VisiBeam consists of a flat probe (diameter 11 mm) with a cylindric plane wave beam, a vacuum attachment (diameter 40 mm), a scanner, and a display. AimsTo assess the feasibility of VisiBeam for continuous fetal CBFV monitoring during labor, and to study changes in CBFV during uterine contractions. Study designDescriptive observational study. SubjectsTwenty-five healthy women in labor with a singleton fetus in cephalic presentation at term. A transducer was placed over a fontanelle and attached to the fetal head with vacuum suction. Outcome measuresAchievement of continuous good quality fetal CBFV measures, such as peak systolic velocity, time averaged maximum velocity and end diastolic velocity. Trend plots of velocity measures display changes in CBFV between and during uterine contractions. ResultsGood quality recordings during and between contractions were achieved in 16/25 fetuses. In twelve fetuses, CBFV measures were stable during uterine contractions. Four fetuses showed patterns of reduced CBFV velocity measures during contractions. ConclusionsContinuous fetal CBFV monitoring by VisiBeam was feasible in 64 % of the subjects during labor. The system displayed variations of fetal CBFV not available by today's monitoring techniques and motivates for further studies. However, improvement of the probe attachment is required to ensure good quality signal in a higher proportion of fetuses during labor.

Influence of rainfall in a short-term seismic velocity monitoring at an urban landslide site in Minas Gerais, Brazil

Most high-magnitude landslides in Brazil are triggered by rainfall. The partial or total liquefaction of the soil mass is directly related to an increase in the pore pressure, which can happen after or during heavy and sustained rainfalls. Traditional near-surface geophysical methods for saturation and rigidity assessment usually involve short-duration data acquisition campaigns, reporting results representative of a specific moment. On the other hand, the cross-correlation of the ambient noise wavefield registered at different locations in continuous data streams has emerged as a promising alternative for monitoring seismic velocity variations in time. In the present study, we evaluate if the observed seismic velocity perturbations can satisfactorily relate to rainfall periods on a local scale and within minutes of resolution at a slope in Itabirito, state of Minas Gerais, Brazil, where landslide activity occurred. We calculate velocity changes in the tail portion (coda) from Green's functions retrieved from cross-correlation of seismic noise time series registered at pairs of stations from September 2022 to November 2022. In the 50 days observation period, the monitored area remained stable. We identified clear time intervals where the relative seismic velocity decreases after or during rainfall, which indicates modification in the saturation conditions of the soil. The results demonstrated that seismic velocity changes obtained from the coda of cross correlations of the ambient noise wavefield could satisfactorily constrain rainfall periods and indicate possible changes in the saturation conditions of the soil at a small local scale with a high temporal resolution.

Continuous monitoring of cerebral blood flow during general anaesthesia in infants

BackgroundGeneral anaesthesia is associated with neurocognitive deficits in infants after noncardiac surgery. Disturbances in cerebral perfusion as a result of systemic hypotension and impaired autoregulation may be a potential cause. Our aim was to study cerebral blood flow (CBF) velocity continuously during general anaesthesia in infants undergoing noncardiac surgery and compare variations in CBF velocity with simultaneously measured near-infrared spectroscopy (NIRS), blood pressure, and heart rate. MethodsNeoDoppler, a recently developed ultrasound system, was used to monitor CBF velocity via the anterior fontanelle during induction and maintenance of general anaesthesia until the start of surgery, and during recovery. NIRS, blood pressure, and heart rate were monitored simultaneously and synchronised with the NeoDoppler measurements. ResultsThirty infants, with a median postmenstrual age at surgery of 37.6 weeks (range 28.6–60.0) were included. Compared with baseline, the trend curves showed a decrease in CBF velocity during induction and maintenance of anaesthesia and returned to baseline values during recovery. End-diastolic velocity decreased in all infants during anaesthesia, on average by 59%, whereas peak systolic- and time-averaged velocities decreased by 26% and 45%, respectively. In comparison, the reduction in mean arterial pressure was only 20%. NIRS values were high and remained stable. When adjusting for mean arterial pressure, the significant decrease in end-diastolic velocity persisted, whereas there was only a small reduction in peak systolic velocity. ConclusionsContinuous monitoring of CBF velocity using NeoDoppler during anaesthesia is feasible and may provide valuable information about cerebral perfusion contributing to a more targeted haemodynamic management in anaesthetised infants.

Implementing a velocity-based approach to resistance training: the reproducibility and sensitivity of different velocity monitoring technologies

This study examined the reproducibility of GymAware, PUSH2 and Vmaxpro velocity monitoring devices during resistance training (RT). The sensitivity of these devices to detect the smallest changes in velocity that correspond to true changes in RT performance was also investigated. Fifty-one resistance-trained men and women performed an incremental loading (1RM) test, and two repetitions to failure tests with different loads, 72 h apart. During all repetitions, mean velocity (MV) and peak velocity (PV) were simultaneously recorded by two devices of each brand. Overall, GymAware was the most reliable and sensitive device for detecting the smallest changes in RT performance, regardless of the velocity metric used. Vmaxpro can be considered as an equivalent, cheaper alternative to GymAware for RT monitoring and prescription, but only if the MV metric is used. Caution should be exercised when using PUSH2 in practice due to their comparatively higher, unacceptable measurement error and generally low sensitivity to detect changes in RT performance. Collectively, these findings support the use of MV and PV from GymAware and MV from Vmaxpro devices for RT monitoring and prescription due to their low magnitudes of error; thus, allowing for the detection of meaningful changes in neuromuscular status and functional performance during RT.

Hypocapnic Orthostatic Intolerance with (POTS) and without (HYCH) Tachycardia Represent a Spectrum of the Same Disorder (S43.003)

<h3>Objective:</h3> To compare postural tachycardia syndrome (POTS) with hypocapnic cerebral hypoperfusion (HYCH). <h3>Background:</h3> Several chronic orthostatic intolerance syndromes are associated with hypocapnia-driven cerebral hypoperfusion. Common syndromes are POTS where orthostatic tachycardia is present, and HYCH, where orthostatic tachycardia is absent. <h3>Design/Methods:</h3> This retrospective study evaluated consecutive patients with POTS and HYCH. Analyzed data included surveys (autonomic and sensory), autonomic (Valsalva maneuver, deep breathing, sudomotor and tilt tests), cerebrovascular (cerebral blood flow velocity (CBFv) monitoring in the middle cerebral artery), respiratory (capnography), neuropathic (skin biopsies for assessment of small fibers) testing and metabolic/inflammatory/autoimmune markers. <h3>Results:</h3> Eighty-one POTS and seventy-two HYCH patients were evaluated and they were compared to 25 healthy controls. POTS and HYCH patients had similar ages, gender, disease duration, and survey scores. Orthostatic CBFv was reduced in HYCH (−22.1±9.4%) and POTS (−23.3±12.0%) compared to controls (−4.4±7.1%,p&lt;0.001). Orthostatic end-tidal CO₂ was reduced in HYCH (27.9±5.6 mmHg) and POTS (27.1±5.6 mmHg) compared to controls (35.3±4.8 mmHg, p&lt;0.001). Orthostatic heart rate was higher in POTS (117±19.3 BPM) compared to HYCH (88.5±15.0 BPM, p&lt;0.001). Mild autonomic failure was present in 91.7% of HYCH and 82.7% of POTS patients. Compared HYCH with POTS, there was no significant difference in the following QASAT scores: sympathetic sudomotor (1.7±1.6/1.3±1.8, HYCH/POTS), parasympathetic cardiovagal (0.4±0.7/0.3±0.6), sympathetic adrenergic (1.2±0.9/1.1±1.0), epidermal fiber density (EFD, 1.8±2.1/1.9/2.4) and sweat gland fiber density (SGF, 1.4±2.0/1.5±2.3). EFD/SGF was abnormal in 63.4%/41.5% of HYCH and 55.8%/43.1% of POTS. Autoimmune markers were positive in 75% of HYCH and 81.5% of POTS. There was no significant difference in supine and orthostatic norepinephrine in both conditions. <h3>Conclusions:</h3> POTS and HYCH have similar abnormalities on subjective and objective measures except for the presence of tachycardia in POTS. Considering that the POTS-grade orthostatic tachycardia (≥30 BPM) can be seen in healthy subjects, these results suggest that HYCH and POTS represent a spectrum of the same disorder. <b>Disclosure:</b> Dr. Novak has received personal compensation for serving as an employee of Dysimmune Disease Foundation. Dr. Novak has stock in Pfeizer. Dr. Novak has stock in Moderna. Dr. Novak has stock in Novavax. Dr. Novak has stock in Editas Medicine. Dr. Novak has stock in Prothena. Dr. Novak has received publishing royalties from a publication relating to health care. Miss Marciano has nothing to disclose.

Operation characteristics of soil blasting vibration test device under vibration load

To improve the accuracy of vibration velocity monitoring during blasting in soil layers, this paper provides a method and device for data correction by combining finite element software and actual engineering test data. Based on the length of the test pedestal exposed to the surface of the geotechnical body, the finite element structural model corresponding to each length of the test pedestal is established. Moreover, a predetermined external excitation load is applied outside the finite element model and the correction function of the vibration data is obtained by analysis of the stress and vibration data. The device solves the problem of low accuracy of vibration velocity measurement in soil and establishes a correction method for measurement data. The results show the following: (1) With the propagation of blasting seismic waves, the maximum stress values of the test device appear in the footwall position, the middle of the extension rod, and the bottom position in that order. (2) At the end of the test, there is an obvious phenomenon of speed amplification at the top of the test device. (3) As the length of the test device exposed to the ground increases, the particle peak vibration velocity (PPV) of the test device varies exponentially with the PPV of the ground and the range of variation of the vibration velocity in the X-direction is the largest.

A 2:1 Mean-motion Resonance Super-Jovian Pair Revealed by TESS, FEROS, and HARPS* *Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere under ESO programmes 105.20GX.001, 108.22A8.001, 110.23YQ.001, and MPG programmes 0106.A-9014, 0107.A-9003, 0108.A-9003, 0109.A-9003, 0110.A-9011.

We report the discovery of a super-Jovian 2:1 mean-motion resonance (MMR) pair around the G-type star TIC 279401253, whose dynamical architecture is a prospective benchmark for planet formation and orbital evolution analysis. The system was discovered thanks to a single-transit event recorded by the Transiting Exoplanet Survey Satellite mission, which pointed to a Jupiter-sized companion with poorly constrained orbital parameters. We began ground-based precise radial velocity (RV) monitoring with HARPS and FEROS within the Warm gIaNts with tEss survey to constrain the transiting body’s period, mass, and eccentricity. The RV measurements revealed not one but two massive planets with periods of and days, respectively. A combined analysis of transit and RV data yields an inner transiting planet with a mass of M Jup and a radius of R Jup, and an outer planet with a minimum mass of M Jup, indicating a massive giant pair. A detailed dynamical analysis of the system reveals that the planets are locked in a strong first-order, eccentricity-type 2:1 MMR, which makes TIC 279401253 one of the rare examples of truly resonant architectures supporting disk-induced planet migration. The bright host star, V ≈ 11.9 mag, the relatively short orbital period (P b = days), and pronounced eccentricity (e = 0.448) make the transiting planet a valuable target for atmospheric investigation with the James Webb Space Telescope and ground-based extremely large telescopes.

The SPIRou legacy survey

Context. The rotation period of stars is an important parameter together with mass, radius, and effective temperature. It is an essential parameter for any radial velocity monitoring, as stellar activity can mimic the presence of a planet at the stellar rotation period. Several methods exist to measure it, including long sequences of photometric measurements or temporal series of stellar activity indicators. Aims. Here, we use the circular polarization in near-infrared spectral lines for a sample of 43 quiet M dwarfs and compare the measured rotation periods to those obtained with other methods. Methods. From Stokes V spectropolarimetric sequences observed with SPIRou at the Canada-France-Hawaii Telescope and the data processed with the APERO pipeline, we computed the least-squares deconvolution profiles using different masks of atomic stellar lines with known Landé factor appropriate to the effective temperature of the star. We derived the longitudinal magnetic field to examine its possible variation in 50 to 200 observations of each star. To determine the stellar rotation period, we applied a Gaussian process regression, enabling us to determine the rotation period of stars with evolving longitudinal field. Results. We were able to measure a rotation period for 27 of the 43 stars of our sample. The rotation period was previously unknown for 8 of these stars. Our rotation periods agree well with periods found in the literature based on photometry and activity indicators, and we confirm that near-infrared spectropolarimetry is an important tool for measuring rotation periods, even for magnetically quiet stars. Furthermore, we computed the ages for 20 stars of our sample using gyrochronology.

Direct Imaging Explorations for Companions around Mid–Late M Stars from the Subaru/IRD Strategic Program

The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late M dwarfs via radial velocity (RV) monitoring. As part of the observing strategy for the exoplanet survey, signatures of massive companions such as RV trends are used to reduce the priority of those stars. However, this RV information remains useful for studying the stellar multiplicity of nearby M dwarfs. To search for companions around such “deprioritized” M dwarfs, we observed 14 IRD-SSP targets using Keck/NIRC2 with pyramid wave-front sensing at NIR wavelengths, leading to high sensitivity to substellar-mass companions within a few arcseconds. We detected two new companions (LSPM J1002+1459 B and LSPM J2204+1505 B) and two new candidates that are likely companions (LSPM J0825+6902 B and LSPM J1645+0444 B), as well as one known companion. Including two known companions resolved by the IRD fiber injection module camera, we detected seven (four new) companions at projected separations between ∼2 and 20 au in total. A comparison of the colors with the spectral library suggests that LSPM J2204+1505 B and LSPM J0825+6902 B are located at the boundary between late M and early L spectral types. Our deep high-contrast imaging for targets where no bright companions were resolved did not reveal any additional companion candidates. The NIRC2 detection limits could constrain potential substellar-mass companions (∼10–75 M Jup) at 10 au or further. The failure with Keck/NIRC2 around the IRD-SSP stars having significant RV trends makes these objects promising targets for further RV monitoring or deeper imaging with the James Webb Space Telescope to search for smaller-mass companions below the NIRC2 detection limits.

Self-powered difunctional sensors based on sliding contact-electrification and tribovoltaic effects for pneumatic monitoring and controlling

Pneumatic elements such as position and velocity sensors play a vital role in pneumatic monitoring and servo control, which have great demands for integration, multifunction and self-powering. Here we propose an integrated triboelectric nanogenerator (TENG) and tribovoltaic nanogenerator (TVNG) in air cylinder as difunctional pneumatic sensor for simultaneous position and velocity monitoring. Based on the sliding contact-electrification between a semicircular PEDOT: PSS film and a circular PTFE polymer, the output voltage of the freestanding-mode TENG can characterize the rotation angle with a resolution superior of 0.02°. While based on the tribovoltaic effect by the friction between an annular PEDOT: PSS film and a circular aluminum electrode, the output current of TVNG can characterize the rotation angular velocity with a detection limit as low as 1 r/min. With the difunctional sensors, the pneumatic monitoring and high precision servo control of the rotary cylinder is realized within the overshoot of 2% and the control error of 1.5%. This work has provided an active sensing strategy for pneumatic monitoring and demonstrated the great prospects of triboelectric sensor in intelligent pneumatic systems.

Predicting timescales of relaxation in the shallow Earth’s subsurface

Earthquakes introduce long-lasting transient mechanical damage in the subsurface, which cause postseismic hazards such as enhanced landsliding and can take years to recover to steady-state values. This observation has been linked to relaxation, a phenomenon observed in a wide class of materials after straining perturbations. In this presentation, I analyze the successive effect of two large earthquakes on ground properties through the monitoring of seismic velocity from ambient noise interferometry in the Atacama desert in Chile. The absence of rainfall in this area allows study of the mechanical state of the subsurface by limiting the potential effect of variable groundwater content. I show that relaxation timescales are a function of the current state of the subsurface when perturbed by earthquakes, rather than ground shaking intensity. Our study highlights the predictability of earthquake damage dynamics in the Earth's near-surface and potentially other materials. I propose to reconcile this paradigm with existing physical frameworks by considering the superposition of different populations of damaged contacts.

Direct discovery of the inner exoplanet in the HD 206893 system

Aims. HD 206893 is a nearby debris disk star that hosts a previously identified brown dwarf companion with an orbital separation of ∼10 au. Long-term precise radial velocity (RV) monitoring, as well as anomalies in the system proper motion, has suggested the presence of an additional, inner companion in the system. Methods. Using information from ongoing precision RV measurements with the HARPS spectrograph, as well as Gaia host star astrometry, we have undertaken a multi-epoch search for the purported additional planet using the VLTI/GRAVITY instrument. Results. We report a high-significance detection over three epochs of the companion HD 206893c, which shows clear evidence for Keplerian orbital motion. Our astrometry with ∼50−100 μarcsec precision afforded by GRAVITY allows us to derive a dynamical mass of 12.7$ ^{+1.2}_{-1.0} $MJup and an orbital separation of 3.53$ ^{+0.08}_{-0.06} $ au for HD 206893c. Our fits to the orbits of both companions in the system use both Gaia astrometry and RVs to also provide a precise dynamical estimate of the previously uncertain mass of the B component, and therefore allow us to derive an age of 155 ± 15 Myr for the system. We find that theoretical atmospheric and evolutionary models that incorporate deuterium burning for HD 206893c, parameterized by cloudy atmosphere models as well as a “hybrid sequence” (encompassing a transition from cloudy to cloud-free), provide a good simultaneous fit to the luminosity of both HD 206893B and c. Thus, accounting for both deuterium burning and clouds is crucial to understanding the luminosity evolution of HD 206893c. Conclusions. In addition to using long-term RV information, this effort is an early example of a direct imaging discovery of a bona fide exoplanet that was guided in part by Gaia astrometry. Utilizing Gaia astrometry is expected to be one of the primary techniques going forward for identifying and characterizing additional directly imaged planets. In addition, HD 206893c is an example of an object narrowly straddling the deuterium-burning limit but unambiguously undergoing deuterium burning. Additional discoveries like this may therefore help clarify the discrimination between a brown dwarf and an extrasolar planet. Lastly, this discovery is another example of the power of optical interferometry to directly detect and characterize extrasolar planets where they form, at ice-line orbital separations of 2−4 au.

An Earth-sized Planet around an M5 Dwarf Star at 22 pc

We report on the discovery of an Earth-sized transiting planet (R p = 1.015 ± 0.051 R ⊕) in a P = 4.02 day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The planet candidate was first identified by analyzing the light-curve data obtained by the K2 mission, and it is here shown to exist in the most recent data from TESS. Combining the light curves with the data secured by our follow-up observations, including high-resolution imaging and near-infrared spectroscopy with IRD, we rule out false-positive scenarios, finding a low false-positive probability of 2 × 10−4. Based on IRD’s radial velocities of K2-415, which were sparsely taken over three years, we obtain a planet mass of 3.0 ± 2.7 M ⊕ (M p < 7.5 M ⊕ at 95% confidence) for K2-415b. Being one of the lowest-mass stars (≈0.16 M ⊙) known to host an Earth-sized transiting planet, K2-415 will be an interesting target for further follow-up observations, including additional radial velocity monitoring and transit spectroscopy.

Improvement of Modeling Velocity of Airflow Created by Emergency Ventilation in a Road Tunnel Using FDS 6

Road tunnels are equipped with various safety installations that enable the tunnel’s autonomous response to fire in order to ensure conditions suitable for safe self-rescue and evacuation. A key role in this effort is played by the monitoring of the longitudinal airflow velocity and its regulation. This study contributes to validation of the Fire Dynamics Simulator (FDS 6) capabilities to model tunnel airflow generated by emergency ventilation. A previous study, in which an FDS 6 model of a real 900 m long motorway tunnel was developed and validated by a full-scale ventilation test, pointed to the relatively high inaccuracies of the average steady-state airflow velocity generated by ventilation measured by tunnel anemometers (13%, 17% and 14% for three ventilation modes). In this paper, it is shown that the application of a modified evaluation procedure and improving the representation of tunnel anemometers leads to the significant improvement of simulation results with inaccuracies of 5%, 1% and 3% for the considered ventilation modes. The observed inaccuracies are even comparable to the measurement accuracy of the tunnel anemometers. A further extension of the modeling of the steady-state airflow velocity generated by emergency ventilation measured by the used anemometers is also described.

Detecting Exomoons from Radial Velocity Measurements of Self-luminous Planets: Application to Observations of HR 7672 B and Future Prospects

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.