We present a semianalytic estimate of the expected yield of single-transit planets from the Transiting Exoplanet Survey Satellite (TESS). We use the TESS Candidate Target List-6 (CTL-6) as an input ...catalog of over four million sources. We predict that from the 200,000 stars selected to be observed with the high-cadence postage stamps (PSs) with the highest CTL-6 priority, there will be 241 single-transit events caused by planets detectable at a signal-to-noise ratio of S/N ≥ 7.3. We find a lower limit of an additional 977 events caused by single-transit planets in the full frame images (FFIs); this is a lower limit because the CTL-6 is incomplete below a TESS magnitude of . Of the single-transit events from the PSs and FFIs, 1091/1218 will have transit depths deeper than 0.1% and will thus be amenable for photometric follow-up from the ground, and 1195/1218 will have radial velocity signals greater than 1 m s−1. We estimate that the periods of 146 single transits will be constrained to better than 10% using the TESS photometry assuming circular orbits. We find that the number of planets detected by TESS in the PSs with periods days can be doubled by including single-transiting planets, while the number of planets with days can be increased by an order of magnitude. We predict 79 habitable zone planets in the TESS light curves from single transits, with 18 orbiting FGK stars.
ABSTRACT We present 15 new transit observations of the exoplanet WASP-43b in the i′, g′, and R filters with the 1.0 m telescopes of Las Cumbres Observatory Global Telescope Network and the IAC80 ...telescope. We combine our 15 new light curves with 52 others from the literature, to homogeneously analyze all the available transit light curves of this exoplanet. By extending the time span of the monitoring of the transits to more than five years, and by analyzing the individual mid-times of 72 transits, we study the proposed shortening of the orbital period of WASP-43b. We estimate that the times of transit are well-matched by our updated ephemeris equation, using a constant orbital period. We estimate an orbital period change rate no larger than P ˙ = −0.02 6.6 ms yr−1, which is fully consistent with a constant period. Based on the timing analysis, we discard stellar tidal dissipation factors Q* < 105. In addition, we update the system parameters: a/Rs = 4.867(23), i = 82.11(10)°, and Rp/Rs = 0.15942(41), noticing a difference in the relative size of the planet between optical and NIR bands.
Results from the Kepler mission indicate that the occurrence rate of small planets (<3 R⊕) in the habitable zone of nearby low-mass stars may be as high as 80%. Despite this abundance, probing the ...conditions and atmospheric properties on any habitable-zone planet is extremely difficult and has remained elusive to date. Here, we report the detection of water vapor and the likely presence of liquid and icy water clouds in the atmosphere of the 2.6 R⊕ habitable-zone planet K2-18b. The simultaneous detection of water vapor and clouds in the mid-atmosphere of K2-18b is particularly intriguing because K2-18b receives virtually the same amount of total insolation from its host star ( 1368 − 107 + 114 W m−2) as the Earth receives from the Sun (1361 W m−2), resulting in the right conditions for water vapor to condense and explain the detected clouds. In this study we observed nine transits of K2-18b using Hubble Space Telescope/WFC3 in order to achieve the necessary sensitivity to detect the water vapor, and we supplement this data set with Spitzer and K2 observations to obtain a broader wavelength coverage. While the thick hydrogen-dominated envelope we detect on K2-18b means that the planet is not a true Earth analog, our observations demonstrate that low-mass habitable-zone planets with the right conditions for liquid water are accessible with state-of-the-art telescopes.
Secondary eclipse observations of several of the hottest hot Jupiters show featureless, blackbody-like spectra or molecular emission features, which are consistent with thermal inversions being ...present in those atmospheres. Theory predicts a transition between warmer atmospheres with thermal inversions and cooler atmospheres without inversions, but the exact transition point is unknown. In order to further investigate this issue, we observed two secondary eclipses of the hot Jupiter HAT-P-7b with the Hubble Space Telescope (HST) WFC3 instrument and combined these data with previous Spitzer and Kepler secondary eclipse observations. The HST and Spitzer data can be well fit by a blackbody with T = 2692 14 K, and the Kepler data point constrains the geometric albedo to Ag = 0.077 0.006. We modeled these data with a three-dimensional (3D) GCM and one-dimensional (1D) self-consistent forward models. The 1D models indicate that the atmosphere has a thermal inversion, weak heat redistribution, and water dissociation that limits the range of pressures probed. This result suggests that WFC3 observations of HAT-P-7b and possibly some other ultra-hot Jupiters appear blackbody-like because they probe a region near the tropopause where the atmospheric temperature changes slowly with pressure. Additionally, the 1D models constrain the atmospheric metallicity ( ) and the carbon-to-oxygen ratio (C/O < 1 at 99% confidence). The solar composition 3D GCM matches the Spitzer data but generally underpredicts the flux in the WFC3 bandpass and cannot reproduce its featureless shape. This discrepancy could be explained by high atmospheric drag or nightside clouds and may be better understood through further observation with the James Webb Space Telescope.
The digital twin solution is an industry 4.0 specific tool that has grown in the past decade, stemming from the modelling and simulation approaches that existed before, complemented by new sensor ...capabilities, cloud processing, big data analytics, and implementation mechanisms. As it is being used mostly in the present by manufacturing companies, the primary focus of the solution is to enhance productivity and reduce costs by optimizing processes and enabling real-time problem-solving, sometimes based on decision-making systems and artificial intelligence. However, as companies are being faced with an increasingly steep list of environmental requirements and regulations, ranging from the classical pollution control and waste recycling to full-scale economic models based on circular economy and transformative carbon dioxide elimination programs, the features of the manufacturing digital twins must also evolve to provide an appropriate answer to these challenges. In this paper, the authors propose a framework for building better digital twins for production systems by incorporating environmental-related functions. The demarches start from analysing existing solutions presented in literature from the point of view of environmental suitability, based on the use of the MoSCoW method for differentiating attributes (into Must have, Should have, Could have, Will not have elements) and determining development alternatives based on the employment of Multi-Criteria Decision Analysis (MCDA) for feature selection, and the TRIZ method (Theory of Inventive Problem-Solving) for application guidelines. The MCDA was performed within a focus group of nine production specialists from regionally successful sectors. We arrive at the conclusion that environmental-related functions are poorly implemented in the digital twins of the present (although more so in integrated solutions and custom-built applications) and that the development of the proper tools, databases, and interpretation keys should proceed immediately in the fields of production engineering, industrial ecology, and software development to support them.
This paper explores the transformations necessary in the field of social responsibility and social accountability employed by manufacturing companies as they transition to a model of smart and ...sustainable production. A focus group of managers in production companies has been interviewed concerning the challenges and support they derive for their environmental and community approaches, as the firms deploy advanced Industry 4.0 tools such as the internet of things, digital twins and virtual reality to upgrade their manufacturing systems and processes. The results are presented and discussed based on a set of ranked objective indicators, and proposals for a future implementation scenario are advanced.
The helium absorption triplet at a wavelength of 10833 has been proposed as a way to probe the escaping atmospheres of exoplanets. Recently this feature was detected for the first time using Hubble ...Space Telescope (HST) WFC3 observations of the hot Jupiter WASP-107b. We use similar HST/WFC3 observations to detect helium in the atmosphere of the hot Neptune HAT-P-11b at the 4 confidence level. We compare our observations to a grid of 1D models of hydrodynamic escape to constrain the thermospheric temperatures and mass loss rate. We find that our data are best fit by models with high mass loss rates of g s−1. Although we do not detect the planetary wind directly, our data are consistent with the prediction that HAT-P-11b is experiencing hydrodynamic atmospheric escape. Nevertheless, the mass loss rate is low enough that the planet has only lost up to a few percent of its mass over its history, leaving its bulk composition largely unaffected. This matches the expectation from population statistics, which indicate that close-in planets with radii greater than 2 R⊕ form and retain H/He-dominated atmospheres. We also confirm the independent detection of helium in HAT-P-11b obtained with the CARMENES instrument, making this the first exoplanet with the detection of the same signature of photoevaporation from both ground- and space-based facilities.
GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple James Webb Space Telescope (JWST) Guaranteed Time Observation programs. Here, we report the ...first space-based optical transmission spectrum of the planet using two Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) transit observations from 0.53 to 1.03 m. We find no evidence for alkali absorption features, nor evidence of a scattering slope longward of 0.53 m. The spectrum is indicative of moderate to high metallicity (∼100-1000× solar), while moderate-metallicity scenarios (∼100× solar) require aerosol opacity. The optical spectrum also rules out some highly scattering haze models. We find an increase in transit depth around 0.8 m in the transmission spectra of three different sub-Jovian exoplanets (GJ 436b, HAT-P-26b, and GJ 1214b). While most of the data come from STIS, data from three other instruments may indicate this is not an instrumental effect. Only the transit spectrum of GJ 1214b is well fit by a model with stellar plages on the photosphere of the host star. Our photometric monitoring of the host star reveals a stellar rotation rate of 44.1 days and an activity cycle of 7.4 years. Intriguingly, GJ 436 does not become redder as it gets dimmer, which is expected if star spots were dominating the variability. These insights into the nature of the GJ 436 system help refine our expectations for future observations in the era of JWST, whose higher precision and broader wavelength coverage will shed light on the composition and structure of GJ 436b's atmosphere.
The article presents a complete approach for the wood industry for assessing the state of circular economy adoption by companies. A methodology for achieving this purpose is proposed and then ...implemented with the help of a specific questionnaire. The study is based on a literature survey with two components, one relating to reports on the concept of circularity and one relating to the methodological aspects of determining and measuring the progress of companies. Starting from these aspects and factoring in the sectoral evolution in Romania, the assessment directions and detailed questions for each are established essentially through a mind-mapping process. For validation, the questionnaire with seven evaluation viewpoints covered in 28 items is applied within the Romanian wood industry to 60 companies. The analysis of results is carried out using descriptive and inferential statical methods, such as ANOVA, showing good progress of the industry at company level, through individual efforts as well as the need to continue the transformation of the sector from the point of view of regulatory oversight and market acceptance. A set of recommendations for companies to advance their situation is proposed to help the maturation of the current circular approaches.
The present study focuses on an up-to-date topic regarding flying equipment identified within the category of drones that use, for propulsion and air movements, the power generated by electric ...motors. In this paper, researchers focus on implementing bladeless technology to calculate, develop, and construct flying equipment known in the literature as drones. The entire structure of the prototype, all the needed parts, is to be obtained using additive manufacturing technologies, which assumes practical realization using 3D-printing equipment. Nowadays, the 3D-printing process has been proven to be a reliable solution when it comes to manufacturing complex shape parts in quite a short time and with reduced costs. The practical study within the present research aims to obtain polymer-based, lightweight parts with complex shapes inside to be implemented in the propulsion of a drone. The complex surface geometry of the parts that this research used is influenced by the ventilation technology offered by the "Air Multiplier" technology. The entire structure of the final drone equipment, all the parts, is to be manufactured using fused filament fabrication (FFF). The main purpose of the fusion is to use the advantages offered by this technology in drones to obtain advantages such as augmented values of thrust, a more agreeable and muffled sound signature, or an increased level of safety.
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