We perform a study of stellar flares for the 24,809 stars observed with 2 minute cadence during the first two months of the TESS mission. Flares may erode exoplanets' atmospheres and impact their ...habitability, but might also trigger the genesis of life around small stars. TESS provides a new sample of bright dwarf stars in our galactic neighborhood, collecting data for thousands of M dwarfs that might host habitable exoplanets. Here, we use an automated search for flares accompanied by visual inspection. Then, our public allesfitter code robustly selects the appropriate model for potentially complex flares via Bayesian evidence. We identify 1228 flaring stars, 673 of which are M dwarfs. Among 8695 flares in total, the largest superflare increased the stellar brightness by a factor of 16.1. Bolometric flare energies range from 1031.0 to 1036.9 erg, with a median of 1033.1 erg. Furthermore, we study the flare rate and energy as a function of stellar type and rotation period. We solidify past findings that fast rotating M dwarfs are the most likely to flare and that their flare amplitude is independent of the rotation period. Finally, we link our results to criteria for prebiotic chemistry, atmospheric loss through coronal mass ejections, and ozone sterilization. Four of our flaring M dwarfs host exoplanet candidates alerted on by TESS, for which we discuss how these effects can impact life. With upcoming TESS data releases, our flare analysis can be expanded to almost all bright small stars, aiding in defining criteria for exoplanet habitability.
ABSTRACT The Transiting Exoplanet Survey Satellite (TESS) is a NASA-sponsored Explorer mission that will perform a wide-field survey for planets that transit bright host stars. Here, we predict the ...properties of the transiting planets that TESS will detect along with the EB stars that produce false-positive photometric signals. The predictions are based on Monte Carlo simulations of the nearby population of stars, occurrence rates of planets derived from Kepler, and models for the photometric performance and sky coverage of the TESS cameras. We expect that TESS will find approximately 1700 transiting planets from pre-selected target stars. This includes 556 planets smaller than twice the size of Earth, of which 419 are hosted by M dwarf stars and 137 are hosted by FGK dwarfs. Approximately 130 of the planets will have host stars brighter than . Approximately 48 of the planets with lie within or near the habitable zone ( ); between 2 and 7 such planets have host stars brighter than . We also expect approximately 1100 detections of planets with radii 2-4 , and 67 planets larger than 4 . Additional planets larger than 2 can be detected around stars that are not among the pre-selected target stars, because TESS will also deliver full-frame images at a 30-minute cadence. The planet detections are accompanied by over 1000 astrophysical false positives. We discuss how TESS data and ground-based observations can be used to distinguish the false positives from genuine planets. We also discuss the prospects for follow-up observations to measure the masses and atmospheres of the TESS planets.
We report the discovery of TOI-172 b from the Transiting Exoplanet Survey Satellite (TESS) mission, a massive hot Jupiter transiting a slightly evolved G star with a 9.48-day orbital period. This is ...the first planet to be confirmed from analysis of only the TESS full frame images, because the host star was not chosen as a two-minute cadence target. From a global analysis of the TESS photometry and follow-up observations carried out by the TESS Follow-up Observing Program Working Group, TOI-172 (TIC 29857954) is a slightly evolved star with an effective temperature of Teff = 5645 50 K, a mass of M = M , radius of R = R , a surface gravity of log g = , and an age of . Its planetary companion (TOI-172 b) has a radius of RP = RJ, a mass of MP = MJ, and is on an eccentric orbit ( ). TOI-172 b is one of the few known massive giant planets on a highly eccentric short-period orbit. Future study of the atmosphere of this planet and its system architecture offer opportunities to understand the formation and evolution of similar systems.
The spectrum of somatic alterations in hematologic malignancies includes substitutions, insertions/deletions (indels), copy number alterations (CNAs), and a wide range of gene fusions; no current ...clinically available single assay captures the different types of alterations. We developed a novel next-generation sequencing-based assay to identify all classes of genomic alterations using archived formalin-fixed paraffin-embedded blood and bone marrow samples with high accuracy in a clinically relevant time frame, which is performed in our Clinical Laboratory Improvement Amendments–certified College of American Pathologists–accredited laboratory. Targeted capture of DNA/RNA and next-generation sequencing reliably identifies substitutions, indels, CNAs, and gene fusions, with similar accuracy to lower-throughput assays that focus on specific genes and types of genomic alterations. Profiling of 3696 samples identified recurrent somatic alterations that impact diagnosis, prognosis, and therapy selection. This comprehensive genomic profiling approach has proved effective in detecting all types of genomic alterations, including fusion transcripts, which increases the ability to identify clinically relevant genomic alterations with therapeutic relevance.
•Novel clinically available comprehensive genomic profiling of both DNA and RNA in hematologic malignancies.•Profiling of 3696 clinical hematologic tumors identified somatic alterations that impact diagnosis, prognosis, and therapeutic selection.
We report on a new method for tracking the phases of the orbital modulations in very short-period, near-contact, and contact binary systems in order to follow starspots. We apply this technique to ...Kepler light curves for 414 binary systems that were identified as having anticorrelated O−C curves for the mid-times of the primary and secondary eclipses, or in the case of non-eclipsing systems, their light-curve minima. This phase tracking approach extracts more information about starspot and binary system behaviour than may be easily obtained from the O−C curves. We confirm the hypothesis of Tran et al. that we can successfully follow the rotational motions of spots on the surfaces of the stars in these binaries. In ∼34 per cent of the systems, the spot rotation is retrograde as viewed in the frame rotating with the orbital motion, while ∼13 per cent show significant prograde spot rotation. The remaining systems show either little spot rotation or erratic behaviour, or sometimes include intervals of both types of behaviour. We discuss the possibility that the relative motions of spots are related to differential rotation of the stars. It is clear from this study that the motions of the starspots in at least 50 per cent of these short-period binaries are not exactly synchronized with the orbits.
We present techniques for bridging the gap between idealized inverse covariance weighted quadratic estimation of 21 cm power spectra and the real-world challenges presented universally by ...interferometric observation. By carefully evaluating various estimators and adapting our techniques for large but incomplete data sets, we develop a robust power spectrum estimation framework that preserves the so-called "Epoch of Reionization (EoR) window" and keeps track of estimator errors and covariances. We apply our method to observations from the 32-tile prototype of the Murchinson Widefield Array to demonstrate the importance of a judicious analysis technique. Lastly, we apply our method to investigate the dependence of the clean EoR window on frequency-especially the frequency dependence of the so-called "wedge" feature-and establish upper limits on the power spectrum from z = 6.2 to z = 11.7. Our lowest limit is Delta (k) < 0.3 Kelvin at 95% confidence at a comoving scale k = 0.046 Mpc super(-1) and z = 9.5.
We ask whether moral judgment in preschool children observes a "means principle." It is well established that young children consider both the consequences and the goals of actions when making moral ...judgments; much less studied is the question of whether the means used to attain a given goal also matter. By obtaining preschoolers' judgments regarding when, if ever, it is permissible for 1 person to harm another as a means, we show, across 2 experiments, that children (N = 200 across 2 studies; Mage = 5.1 yrs.) use the means principle in their moral judgments. Subjects recognized not only when a harm was being used as a means but also situated that means appropriately with respect to the correct superordinate goal. In this respect, the preschoolers in this sample are like adults across a wide range of cultures. These findings have important implications for the understanding of moral development: young children can use an agent's means, and not just her goal, to make a moral judgment. We discuss the broader issue of whether, in light of emerging evidence for the means principle, there really are any moral universals.
Kawahara and collaborators analysed the transits of the candidate disintegrating Mercury-mass planet KIC 12557548b and suggested that the transit depths were correlated with the phase of the stellar ...rotation. We have carried out a more extensive and comprehensive analysis of the transit depths of KIC 12557548b and confirm that there is indeed a robust, statistically significant signal in the transit depths at the rotation period of the spotted host star. This signal is more prominent in the first-half of the Kepler data, and is not due to leakage of the rotating spot signal into our measurement of the transit depths, or due to unocculted starspots. We quantitatively investigate the suggestion that this signal could be due to an active region on the star, emitting enhanced ultraviolet or X-ray radiation leading to an increased mass-loss rate of the planet; we demonstrate that such a scenario could cause both modulation of the transit depths of KIC 12557548b, and small enough transit-timing variations that they might not be detected in the Kepler data. Our preferred explanation, however, for the fact that the transit depths of KIC 12557548b are modulated with the stellar rotation phase is that the candidate transiting planet is occulting starspots on this highly spotted star; such a scenario could cause transit depth variations as large as have been observed, and cause transit-timing variations small enough that they are arguably consistent with the Kepler data.
Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for ...sodium-ion batteries (SIBs). Tire-derived carbons obtained by pyrolyzing acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g−1, respectively, after 100 cycles at a current density of 20 mA g−1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.
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•Carbon composites were successfully prepared from waste tires for Na-ion batteries.•Tire-derived carbon anodes show good capacities and stabilities after long cycling.•The capacity plateau below 0.2 V increases drastically with pyrolysis temperature.•Demonstrated a low-cost and environmentally friendly anode for energy storage.
The presumption of innocence is not only a bedrock principle of American law, but also a fundamental human right. The psychological underpinnings of this presumption, however, are not well ...understood. To make progress, one important task is to explain how adults and children infer the goals and intentional structure of complex actions, especially when a single action has more than one salient effect. Many theories of moral judgment have either ignored this intention inference problem or have simply assumed a particular solution without empirical support. We propose that this problem may be solved by appealing to domain-specific prior knowledge that is either built-up over the probability of prior intentions or built-in as part of core cognition. We further propose a specific solution to this problem in the moral domain: a good intention prior, which entails a rebuttable presumption that if an action has both good and bad effects, the actor intends the good effects and not the bad effects. Finally, in a series of novel experiments we provide the first empirical support - from both adults and preschool children - for the existence of this good intention prior.
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