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Highly irradiated planets in the hot Neptune desert are usually either small (R < 2 Rearth) and rocky or they are gas giants with radii of >1 Rjup. Here, we report on the intermediate-sized planet TOI-2196 on a 1.2 day orbit around a G-type star discovered by TESS in sector 27. We collected 42 radial velocity measurements with the HARPS spectrograph to determine the mass. The radius of TOI-2196 b is 3.51 +/- 0.15 Rearth, which, combined with the mass of 26.0 +/- 1.3 Mearth, results in a bulk density of 3.31+0.51-0.43 g/cm3. Hence, the radius implies that this planet is a sub-Neptune, although the density is twice than that of Neptune. A significant trend in the HARPS radial velocities points to the presence of a distant companion with a lower limit on the period and mass of 220 days and 0.65 Mjup, respectively, assuming zero eccentricity. The short period of planet b implies a high equilibrium temperature of 1860 +/- 20 K, for zero albedo and isotropic emission. This places the planet in the hot Neptune desert, joining a group of very few planets in this parameter space discovered in recent years. These planets suggest that the hot Neptune desert may be divided in two parts for planets with equilibrium temperatures of > 1800 K: a hot sub-Neptune desert devoid of planets with radii of 1.8-3 Rearth and a sub-Jovian desert for radii of 5-12 Rearth. More planets in this parameter space are needed to further investigate this finding. Planetary interior structure models of TOI-2196 b are consistent with a H/He atmosphere mass fraction between 0.4 % and 3 %, with a mean value of 0.7 % on top of a rocky interior. We estimated the amount of mass this planet might have lost at a young age, and we find that while the mass loss could have been significant, the planet had not changed in terms of character: it was born as a small volatile-rich planet, and it remains one at present., 17 pages, 15 figures, 7 tables, accepted 11 July 2022 for publication in Astronomy & Astrophysics

We report the discovery of ten short-period giant planets (TOI-2193A b, TOI-2207 b, TOI-2236 b, TOI-2421 b, TOI-2567 b, TOI-2570 b, TOI-3331 b, TOI-3540A b, TOI-3693 b, TOI-4137 b). All of the planets were identified as planet candidates based on periodic flux dips observed by NASA's Transiting Exoplanet Survey Satellite (TESS). The signals were confirmed to be from transiting planets using ground-based time-series photometry, high angular resolution imaging, and high-resolution spectroscopy coordinated with the TESS Follow-up Observing Program. The ten newly discovered planets orbit relatively bright F and G stars ($G < 12.5$,~$T_\mathrm{eff}$ between 4800 and 6200 K). The planets' orbital periods range from 2 to 10~days, and their masses range from 0.2 to 2.2 Jupiter masses. TOI-2421 b is notable for being a Saturn-mass planet and TOI-2567 b for being a ``sub-Saturn'', with masses of $0.322\pm 0.073$ and $0.195\pm 0.030$ Jupiter masses, respectively. In most cases, we have little information about the orbital eccentricities. Two exceptions are TOI-2207 b, which has an 8-day period and a detectably eccentric orbit ($e = 0.17\pm0.05$), and TOI-3693 b, a 9-day planet for which we can set an upper limit of $e < 0.052$. The ten planets described here are the first new planets resulting from an effort to use TESS data to unify and expand on the work of previous ground-based transit surveys in order to create a large and statistically useful sample of hot Jupiters., 44 pages, 15 tables, 21 figures; revised version submitted to AJ

A conductive network of waste-tire derived carbon (WTC) was used to produce homogeneous Sb/WTC and Sb2O3/WTC composite materials via ball milling as promising anodes for sodium-ion batteries (SIBs). Highly reversible redox peaks at 0.81/0.71, 0.25 V for Sb/WTC and 0.80/0.76, 0.21/0.26 V for Sb2O3/WTC anodes have been observed related to Na+ intercalation and deintercalation in carbon and Na–Sb and Na3Sb as plausible conversion/alloy reactions. Sodium half-cells delivered reversible discharge capacities of 206 mA h g−1 and 207 mA h g−1 at a current density of 37 mA g−1 for the composite Sb/WTC and Sb2O3/WTC materials, respectively. Both the Sb/WTC and Sb2O3/WTC composite materials showed impressive capacity retention with 85% and 88%, respectively after 100 cycles. Rate capability studies at 60 °C yielded an enhanced capacity of 240 mA h g−1 for Sb/WTC and 300 mA h g−1 for Sb2O3/WTC at 37 mA g−1.

We present an analysis of the first 20 second cadence light curves obtained by the TESS space telescope during its extended mission. We find improved precision of 20 second data compared to 2 minute data for bright stars when binned to the same cadence (˜10%-25% better for T ? 8 mag, reaching equal precision at T ˜ 13 mag), consistent with pre-flight expectations based on differences in cosmic-ray mitigation algorithms. We present two results enabled by this improvement. First, we use 20 second data to detect oscillations in three solar analogs (? Pav, ? Tuc, and p Men) and use asteroseismology to measure their radii, masses, densities, and ages to ˜1%, ˜3%, ˜1%, and ˜20% respectively, including systematic errors. Combining our asteroseismic ages with chromospheric activity measurements, we find evidence that the spread in the activity-age relation is linked to stellar mass and thus the depth of the convection zone. Second, we combine 20 second data and published radial velocities to recharacterize p Men c, which is now the closest transiting exoplanet for which detailed asteroseismology of the host star is possible. We show that p Men c is located at the upper edge of the planet radius valley for its orbital period, confirming that it has likely retained a volatile atmosphere and that the "asteroseismic radius valley"remains devoid of planets. Our analysis favors a low eccentricity for p Men c (, D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC19K0379, 80NSSC21K0652), and the National Science Foundation (AST-1717000). T.S.M. acknowledges support from NASA grant 80NSSC20K0458. Computational time at the Texas Advanced Computing Center was provided through XSEDE allocation TG-AST090107. A.C. acknowledges support from the National Science Foundation through the Graduate Research Fellowship Program (DGE 1842402). W.H.B. performed computations using the University of Birmingham's BlueBEAR High Performance Computing service. T.R.B. acknowledges support from the Australian Research Council through Discovery Project DP210103119. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant DNRF106). M.S.C. and M.D. acknowledge the support by FCT/MCTES through the research grants UIDB/04434/2020, UIDP/04434/2020 and PTDC/FIS-AST/30389/2017, and by FEDER—Fundo Europeu de Desenvolvimento Regional through COMPETE2020—Programa Operacional Competitividade e Internacionalização (grant: POCI-01-0145-FEDER-030389). T.L.C. is supported by Fundação para a Ciência e a Tecnologia (FCT) in the form of a work contract (CEECIND/00476/2018). M.S.C. is supported by national funds through FCT in the form of a work contract. H.K. and E.P. acknowledge the grant from the European Social Fund via the Lithuanian Science Council (LMTLT) grant No. 09.3.3-LMT-K-712-01-0103. R.A.G. and S.N.B. acknowledge the support received from the CNES with the PLATO and GOLF grants. B.N. acknowledges postdoctoral funding from the Alexander von Humboldt Foundation and "Branco Weiss fellowship Science in Society" through the SEISMIC stellar interior physics group. S.M. acknowledges support by the Spanish Ministry of Science and Innovation with the Ramon y Cajal fellowship number RYC-2015-17697 and the grant number PID2019-107187GB-I00. T.W. acknowledges support from the B-type Strategic Priority Program of the Chinese Academy of Sciences (grant No. XDB41000000) from the NSFC of China (grant Nos. 11773064, 11873084, and 11521303), from the Youth Innovation Promotion Association of Chinese Academy of Sciences, and from the Ten Thousand Talents Program of Yunnan for Top-notch Young Talents. T.W. also gratefully acknowledges the computing time granted by the Yunnan Observatories and provided by the facilities at the Yunnan Observatories Supercomputing Platform. T.D. acknowledges support from MIT's Kavli Institute as a Kavli postdoctoral fellow.

Full list of authors: Tran, Quang H.; Bowler, Brendan P.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Gandolfi, Davide; Persson, Carina M.; Fridlund, Malcolm; Palle, Enric; Nowak, Grzegorz; Deeg, Hans J.; Luque, Rafael; Livingston, John H.; Kabáth, Petr; Skarka, Marek; Šubjak, Ján; Howell, Steve B.; Albrecht, Simon H.; Collins, Karen A.; Esposito, Massimiliano; Van Eylen, Vincent; Grziwa, Sascha; Goffo, Elisa; Huang, Chelsea X.; Jenkins, Jon M.; Karjalainen, Marie; Karjalainen, Raine; Knudstrup, Emil; Korth, Judith; Lam, Kristine W. F.; Latham, David W.; Levine, Alan M.; Osborne, H. L. M.; Quinn, Samuel N.; Redfield, Seth; Ricker, George R.; Seager, S.; Serrano, Luisa Maria; Smith, Alexis M. S.; Twicken, Joseph D.; Winn, Joshua N.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We report the discovery of two transiting planets around the bright (V = 9.9 mag) main-sequence F7 star TOI-1670 by the Transiting Exoplanet Survey Satellite. TOI-1670 b is a sub-Neptune (${R}_{{\rm{b}}}={2.06}_{-0.15}^{+0.19}$ R⊕) on a 10.9 day orbit, and TOI-1670 c is a warm Jupiter (${R}_{{\rm{c}}}={0.987}_{-0.025}^{+0.025}$ RJup) on a 40.7 day orbit. Using radial velocity observations gathered with the Tull Coudé Spectrograph on the Harlan J. Smith telescope and HARPS-N on the Telescopio Nazionale Galileo, we find a planet mass of ${M}_{{\rm{c}}}={0.63}_{-0.08}^{+0.09}$ MJup for the outer warm Jupiter, implying a mean density of ${\rho }_{c}={0.81}_{-0.11}^{+0.13}$ g cm−3. The inner sub-Neptune is undetected in our radial velocity data (Mb < 0.13 MJup at the 99% confidence level). Multiplanet systems like TOI-1670 hosting an outer warm Jupiter on a nearly circular orbit (${e}_{{\rm{c}}}={0.09}_{-0.04}^{+0.05}$) and one or more inner coplanar planets are more consistent with "gentle" formation mechanisms such as disk migration or in situ formation rather than high-eccentricity migration. Of the 11 known systems with a warm Jupiter and a smaller inner companion, eight (73%) are near a low-order mean-motion resonance, which can be a signature of migration. TOI-1670 joins two other systems (27% of this subsample) with period commensurabilities greater than 3, a common feature of in situ formation or halted inward migration. TOI-1670 and the handful of similar systems support a diversity of formation pathways for warm Jupiters. © 2022. The Author(s). Published by the American Astronomical Society., Q.H.T. and B.P.B. acknowledge support from a NASA FINESST grant (80NSSC20K1554). This work benefited from involvement in ExoExplorers, which is sponsored by the Exoplanets Program Analysis Group (ExoPAG) and NASA's Exoplanet Exploration Program Office (ExEP). B.P.B. acknowledges support from National Science Foundation grant AST-1909209 and NASA Exoplanet Research Program grant 20-XRP20_2-0119. C.M.P. and M.F. gratefully acknowledge the support of the Swedish National Space Agency (DNR 65/19 and 177/19). J.K. gratefully acknowledges the support of the Swedish National Space Agency (SNSA; DNR 2020-00104). P.K., M.S., J.S., and R.K. acknowledge the financial support of Inter-transfer grant No. LTT-20015. M.K. acknowledges support from ESAs PEA4000127913. M.E. acknowledges the support of the DFG priority program SPP 1992 "Exploring the Diversity of Extrasolar Planets" (HA 3279/12-1). Funding for the Stellar Astrophysics Centre is provided by the Danish National Research Foundation (grant agreement No. DNRF106). D.G. and L.M.S. gratefully acknowledge financial support from the Cassa di Risparmio di Torino (CRT) foundation under grant No. 2018.2323 "Gaseous or rocky? Unveiling the nature of small worlds." This work is partly supported by JSPS KAKENHI grant No. JP20K14518 and SATELLITE Research from Astrobiology Center (AB022006). Funding for the TESS mission is provided by NASA's Science Mission Directorate. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. We acknowledge the use of public TESS data from pipelines at the TESS Science Office and the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This paper includes data collected by the TESS mission that are publicly available from the Mikulski Archive for Space Telescopes (MAST)., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Giant planets on short-period orbits are predicted to be inflated and eventually engulfed by their host stars. However, the detailed timescales and stages of these processes are not well known. Here we present the discovery of three hot Jupiters (P $, Comment: 22 pages, 15 figures, accepted for publication in the Astronomical Journal

We describe the target selection procedure by which stars are selected for 2-minute and 20-second observations by TESS. We first list the technical requirements of the TESS instrument and ground systems processing that limit the total number of target slots. We then describe algorithms used by the TESS Payload Operation Center (POC) to merge candidate targets requested by the various TESS mission elements (the Target Selection Working Group, TESS Asteroseismic Science Consortium, and Guest Investigator office). Lastly, we summarize the properties of the observed TESS targets over the two-year primary TESS mission. We find that the POC target selection algorithm results in 2.1 to 3.4 times as many observed targets as target slots allocated for each mission element. We also find that the sky distribution of observed targets is different from the sky distributions of candidate targets due to technical constraints that require a relatively even distribution of targets across the TESS fields of view. We caution researchers exploring statistical analyses of TESS planet-host stars that the population of observed targets cannot be characterized by any simple set of criteria applied to the properties of the input Candidate Target Lists., 15 pages, 6 figures, accepted for publication in PASP

We use TESS, Spitzer, ground-based light curves and HARPS spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate TOI-674b. We perform a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. We confirm and characterize TOI-674b, a low-density super-Neptune transiting a nearby M dwarf. The host star (TIC 158588995, $V = 14.2$ mag, $J = 10.3$ mag) is characterized by its M2V spectral type with $\mathrm{M}_\star=0.420\pm 0.010$ M$_\odot$, $\mathrm{R}_\star = 0.420\pm 0.013$ R$_\odot$, and $\mathrm{T}_{\mathrm{eff}} = 3514\pm 57$ K, and is located at a distance $d=46.16 \pm 0.03$ pc. Combining the available transit light curves plus radial velocity measurements and jointly fitting a circular orbit model, we find an orbital period of $1.977143 \pm 3\times 10^{-6}$ days, a planetary radius of $5.25 \pm 0.17$ $\mathrm{R}_\oplus$, and a mass of $23.6 \pm 3.3$ $\mathrm{M}_\oplus$ implying a mean density of $\rho_\mathrm{p} = 0.91 \pm 0.15$ [g cm$^{-3}$]. A non-circular orbit model fit delivers similar planetary mass and radius values within the uncertainties. Given the measured planetary radius and mass, TOI-674b is one of the largest and most massive super-Neptune class planets discovered around an M type star to date. It is also a resident of the so-called Neptunian desert and a promising candidate for atmospheric characterisation using the James Webb Space Telescope., Comment: 22 pages, 16 figures. Accepted for publication in A&A

Novel meso- and microporous tire-derived carbon framework as a support for magnetic iron oxide nanoparticle adsorbents (MNA) that selectively adsorb selenite (Se(IV)) ions from contaminated water h...

TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS Mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations (TTVs). Precise characterization of the planets' masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial velocity measurements using HARPS, FEROS, and PFS break that degeneracy, and an expanded TTV baseline from TESS and an ongoing ground-based transit observing campaign increase the precision of the mass and eccentricity measurements. We determine that TOI-216c is a warm Jupiter, TOI-216b is an eccentric warm Neptune, and that they librate in the 2:1 resonance with a moderate libration amplitude of 60 +/- 2 degrees; small but significant free eccentricity of 0.0222 +0.0005/-0.0003 for TOI-216b; and small but significant mutual inclination of 1.2-3.9 degrees (95% confidence interval). The libration amplitude, free eccentricity, and mutual inclination imply a disturbance of TOI-216b before or after resonance capture, perhaps by an undetected third planet., Comment: AJ accepted

Young exoplanets can offer insight into the evolution of planetary atmospheres, compositions, and architectures. We present the discovery of the young planetary system TOI 451 (TIC 257605131, Gaia DR2 4844691297067063424). TOI 451 is a member of the 120-Myr-old Pisces--Eridanus stream (Psc--Eri). We confirm membership in the stream with its kinematics, its lithium abundance, and the rotation and UV excesses of both TOI 451 and its wide binary companion, TOI 451 B (itself likely an M dwarf binary). We identified three candidate planets transiting in the TESS data and followed up the signals with photometry from Spitzer and ground-based telescopes. The system comprises three validated planets at periods of 1.9, 9.2 and 16 days, with radii of 1.9, 3.1, and 4.1 Earth radii, respectively. The host star is near-solar mass with V=11.0 and H=9.3 and displays an infrared excess indicative of a debris disk. The planets offer excellent prospects for transmission spectroscopy with HST and JWST, providing the opportunity to study planetary atmospheres that may still be in the process of evolving., 20 pages, appendix on UV excess

The current severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) pandemic has highlighted the need for personal protective equipment, specifically filtering facepiece respirators like N95 masks While it is common knowledge that polypropylene (PP) is the industry standard material for filtration media, trial and error is often required to identify suitable commercial precursors for filtration media production This work aims to identify differences between several commercial grades of PP and demonstrate the development of N95 filtration media with the intent that the industry partners can pivot and help address N95 shortages Three commercial grades of high melt flow index PP were melt blown at Oak Ridge National Laboratory and broadly characterized by several methods including differential scanning calorimetry (DSC), X-ray diffraction (XRD), and neutron scattering Despite the apparent similarities (high melt flow and isotacticity) between PP feedstocks, the application of corona charging and charge enhancing additives improve each material to widely varying degrees From the analysis performed here, the most differentiating factor appears to be related to crystallization of the polymer and the resulting electret formation Materials with higher crystallization onset temperatures, slower crystallization rates, and larger number of crystallites form a stronger electret and are more effective at filtration © XXXX American Chemical Society

We present the discovery of a highly irradiated and moderately inflated ultra-hot Jupiter, TOI-1431b/MASCARA-5b (HD 201033b), first detected by NASA's Transiting Exoplanet Survey Satellite mission (TESS) and the Multi-site All-Sky CAmeRA (MASCARA). The signal was established to be of planetary origin through radial velocity measurements obtained using SONG, SOPHIE, FIES, NRES, and EXPRES, which show a reflex motion of $K=294.1\pm1.1$ m s$^{-1}$. A joint analysis of the TESS and ground-based photometry and radial velocity measurements reveals that TOI-1431b has a mass of $M_{p}=3.12\pm0.18$ $\rm{M_J}$ ($990\pm60$ M$_{\oplus}$), an inflated radius of $R_{p}=1.49\pm0.05$ $\rm{R_J}$ ($16.7\pm0.6$ R$_{\oplus}$), and an orbital period of $P=2.650237\pm0.000003$ d. Analysis of the spectral energy distribution of the host star reveals that the planet orbits a bright ($\mathrm{V}=8.049$ mag) and young ($0.29^{+0.32}_{-0.19}$ Gyr) Am type star with $T_{\rm eff}=7690^{+400}_{-250}$ $\rm{K}$, resulting in a highly irradiated planet with an incident flux of $\langle F \rangle=7.24^{+0.68}_{-0.64}\times$10$^9$ erg s$^{-1}$ cm$^{-2}$ ($5300^{+500}_{-470}\mathrm{S_{\oplus}}$) and an equilibrium temperature of $T_{eq}=2370\pm70$ K. TESS photometry also reveals a secondary eclipse with a depth of $127^{+4}_{-5}$ppm as well as the full phase curve of the planet's thermal emission in the red-optical. This has allowed us to measure the dayside and nightside temperature of its atmosphere as $T_\mathrm{day}=3004\pm64$ K and $T_\mathrm{night}=2583\pm63$ K, the second hottest measured nightside temperature. The planet's low day/night temperature contrast ($\sim$420 K) suggests very efficient heat transport between the dayside and nightside hemispheres., Accepted for publication in the Astronomical Journal. 39 pages, 18 figures, and 4 tables

Space-based transit missions such as Kepler and TESS have demonstrated that planets are ubiquitous. However, the success of these missions heavily depends on ground-based radial velocity (RV) surveys, which combined with transit photometry can yield bulk densities and orbital properties. While most Kepler host stars are too faint for detailed follow-up observations, TESS is detecting planets orbiting nearby bright stars that are more amenable to RV characterization. Here we introduce the TESS-Keck Survey (TKS), an RV program using ~100 nights on Keck/HIRES to study exoplanets identified by TESS. The primary survey aims are investigating the link between stellar properties and the compositions of small planets; studying how the diversity of system architectures depends on dynamical configurations or planet multiplicity; identifying prime candidates for atmospheric studies with JWST; and understanding the role of stellar evolution in shaping planetary systems. We present a fully-automated target selection algorithm, which yielded 103 planets in 86 systems for the final TKS sample. Most TKS hosts are inactive, solar-like, main-sequence stars (4500 K < Teff < 6000 K) at a wide range of metallicities. The selected TKS sample contains 71 small planets (Rp < 4 Re), 11 systems with multiple transiting candidates, 6 sub-day period planets and 3 planets that are in or near the habitable zone of their host star. The target selection described here will facilitate the comparison of measured planet masses, densities, and eccentricities to predictions from planet population models. Our target selection software is publicly available (at https://github.com/ashleychontos/sort-a-survey) and can be adapted for any survey which requires a balance of multiple science interests within a given telescope allocation., 23 pages, 10 figures, 5 tables

We report the detection of the first circumbinary planet found by TESS. The target, a known eclipsing binary, was observed in sectors 1 through 12 at 30-minute cadence and in sectors 4 through 12 at two-minute cadence. It consists of two stars with masses of 1.1 MSun and 0.3 MSun on a slightly eccentric (0.16), 14.6-day orbit, producing prominent primary eclipses and shallow secondary eclipses. The planet has a radius of ~6.9 REarth and was observed to make three transits across the primary star of roughly equal depths (~0.2%) but different durations -- a common signature of transiting circumbinary planets. Its orbit is nearly circular (e ~ 0.09) with an orbital period of 95.2 days. The orbital planes of the binary and the planet are aligned to within ~1 degree. To obtain a complete solution for the system, we combined the TESS photometry with existing ground-based radial-velocity observations in a numerical photometric-dynamical model. The system demonstrates the discovery potential of TESS for circumbinary planets, and provides further understanding of the formation and evolution of planets orbiting close binary stars., Comment: 35 pages, 21 figures, 6 tables

We report the discovery and validation of TOI 122b and TOI 237b, two warm planets transiting inactive M dwarfs observed by \textit{TESS}. Our analysis shows TOI 122b has a radius of 2.72$\pm$0.18 R$_\rm{e}$ and receives 8.8$\pm$1.0$\times$ Earth's bolometric insolation, and TOI 237b has a radius of 1.44$\pm$0.12 R$_\rm{e}$ and receives 3.7$\pm$0.5$\times$ Earth insolation, straddling the 6.7$\times$ Earth insolation that Mercury receives from the sun. This makes these two of the cooler planets yet discovered by \textit{TESS}, even on their 5.08-day and 5.43-day orbits. Together, they span the small-planet radius valley, providing useful laboratories for exploring volatile evolution around M dwarfs. Their relatively nearby distances (62.23$\pm$0.21 pc and 38.11$\pm$0.23 pc, respectively) make them potentially feasible targets for future radial velocity follow-up and atmospheric characterization, although such observations may require substantial investments of time on large telescopes., Comment: 21 pages, 9 figures, 4 tables, accepted to AJ

We present $Spitzer$ 4.5$��$m observations of the transit of TOI-700 d, a habitable zone Earth-sized planet in a multiplanet system transiting a nearby M-dwarf star (TIC 150428135, 2MASS J06282325-6534456). TOI-700 d has a radius of $1.144^{+0.062}_{-0.061}R_\oplus$ and orbits within its host star's conservative habitable zone with a period of 37.42 days ($T_\mathrm{eq} \sim 269$K). TOI-700 also hosts two small inner planets (R$_b$=$1.037^{+0.065}_{-0.064}R_\oplus$ & R$_c$=$2.65^{+0.16}_{-0.15}R_\oplus$) with periods of 9.98 and 16.05 days, respectively. Our $Spitzer$ observations confirm the TESS detection of TOI-700 d and remove any remaining doubt that it is a genuine planet. We analyze the $Spitzer$ light curve combined with the 11 sectors of TESS observations and a transit of TOI-700 c from the LCOGT network to determine the full system parameters. Although studying the atmosphere of TOI-700 d is not likely feasible with upcoming facilities, it may be possible to measure the mass of TOI-700 d using state-of-the-art radial velocity instruments (expected RV semi-amplitude of $\sim$70 cm/s)., 14 Pages, 5 Figures, 2 Tables, Accepted to AJ

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 10^31.0 to 10^36.9 erg, with a median of 10^33.1 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., Published in The Astronomical Journal, 159, 60. 21 pages, 11 figures, 2 tables. This is the authors' version of the manuscript

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside the pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. The as-synthesized anode yielded a capacity of 690 mAh g−1 after 300 cycles at a current density of 40 mA g−1 with a stable battery performance. A method to prepare low-cost carbon/tin (II) oxide (SnO) composite by ball milling is reported. SnO powders are uniformly distributed inside the carbon matrix, which could effectively absorb the volume expansion of Sn and alleviate capacity fade. The anode yields a capacity of 690 mAh g−1 after 300 cycles.

We report the detection of a transiting planet around π Men (HD 39091), using data from the Transiting Exoplanet Survey Satellite (TESS). The solar-type host star is unusually bright (V = 5.7) and was already known to host a Jovian planet on a highly eccentric, 5.7-year orbit. The newly discovered planet has a size of 2.04 ± 0.05 R(⊕) and an orbital period of 6.27 days. Radial-velocity data from the HARPS and AAT/UCLES archives also displays a 6.27-day periodicity, confirming the existence of the planet and leading to a mass determination of 4.82±0.85 M(⊕). The star’s proximity and brightness will facilitate further investigations, such as atmospheric spectroscopy, asteroseismology, the Rossiter–McLaughlin effect, astrometry, and direct imaging.

We present early time light curves of Type Ia supernovae observed in the first six sectors of TESS data. Ten of these supernovae were discovered by ASAS-SN, seven by ATLAS, six by ZTF, and one by \textit{Gaia}. For nine SNe with sufficient dynamic range ($>$3.0 mag from detection to peak), we fit power law models and search for signatures of companion stars. We find a diversity of early time light curve shapes, although most of our sources are consistent with fireball models where the flux increases $\propto t^2$. Three SN display a flatter rise with flux $\propto t$. We do not find any evidence for additional structure such as multiple power law components in the early rising light curves. For assumptions about the SN properties and the observer viewing angle, and further assuming that companion stars would be in Roche-lobe overflow, we place limits on the radii of companions for six SNe with complete coverage of the early time light curves. The upper limits are $\lesssim$\,32 R$_\odot$ for these six supernovae, $\lesssim$\,20 R$_\odot$ for five of these six, and $\lesssim$\,4 R$_\odot$ for two of these six. The small sample size does not constrain occurrence rates of single degenerate Type Ia SN progenitors, but we expect that TESS observed enough SNe in its primary mission (26 sectors) to inform this measurement. We also show that TESS is capable of detecting emission from a 1 \rsun\ companion for a Type Ia SN within 50 Mpc, and may do so after about six years., Published in ApJ. 57 pages, 42 figures

We present the discovery of TOI 540 b, a hot planet slightly smaller than Earth orbiting the low-mass star 2MASS J05051443-4756154. The planet has an orbital period of $P = 1.239149$ days ($\pm$ 170 ms) and a radius of $r = 0.903 \pm 0.052 R_{\rm Earth}$, and is likely terrestrial based on the observed mass-radius distribution of small exoplanets at similar insolations. The star is 14.008 pc away and we estimate its mass and radius to be $M = 0.159 \pm 0.014 M_{\rm Sun}$ and $R = 0.1895 \pm 0.0079 R_{\rm Sun}$, respectively. The star is distinctive in its very short rotational period of $P_{\rm rot} = 17.4264 +/- 0.0094$ hours and correspondingly small Rossby number of 0.007 as well as its high X-ray-to-bolometric luminosity ratio of $L_X / L_{\rm bol} = 0.0028$ based on a serendipitous XMM-Newton detection during a slew operation. This is consistent with the X-ray emission being observed at a maximum value of $L_X / L_{\rm bol} \simeq 10^{-3}$ as predicted for the most rapidly rotating M dwarfs. TOI 540 b may be an alluring target to study atmospheric erosion due to the strong stellar X-ray emission. It is also among the most accessible targets for transmission and emission spectroscopy and eclipse photometry with JWST, and may permit Doppler tomography with high-resolution spectroscopy during transit. This discovery is based on precise photometric data from TESS and ground-based follow-up observations by the MEarth team., Comment: 18 pages, 7 figures. Accepted for publication in The Astronomical Journal

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.

The exoplanet HD 118203 b, orbiting a bright (V = 8.05) host star, was discovered using the radial velocity method by da Silva et al. (2006), but was not previously known to transit. TESS photometry has revealed that this planet transits its host star. Five planetary transits were observed by TESS, allowing us to measure the radius of the planet to be $1.133 \pm 0.031 R_J$, and to calculate the planet mass to be $2.173 \pm 0.078 M_J$. The host star is slightly evolved with an effective temperature of $T_{\rm eff} = 5692 \pm 83$ K and a surface gravity of ${\rm log}(g) = 3.891 \pm 0.019$. With an orbital period of $6.134980 \pm 0.000038$ days and an eccentricity of $0.316 \pm 0.021$, the planet occupies a transitional regime between circularized hot Jupiters and more dynamically active planets at longer orbital periods. The host star is among the ten brightest known to have transiting giant planets, providing opportunities for both planetary atmospheric and asteroseismic studies., 15 pages, 6 figures, submitted to AAS Journals

We report the detection of a transiting planet around $\pi$ Mensae (HD 39091), using data from the Transiting Exoplanet Survey Satellite (TESS). The solar-type host star is unusually bright (V=5.7) and was already known to host a Jovian planet on a highly eccentric, 5.7-year orbit. The newly discovered planet has a size of $2.04\pm 0.05$ $R_\oplus$ and an orbital period of 6.27 days. Radial-velocity data from the HARPS and AAT/UCLES archives also displays a 6.27-day periodicity, confirming the existence of the planet and leading to a mass determination of $4.82\pm 0.85$ $M_\oplus$. The star's proximity and brightness will facilitate further investigations, such as atmospheric spectroscopy, asteroseismology, the Rossiter--McLaughlin effect, astrometry, and direct imaging., Comment: Accepted for publication ApJ Letters. This letter makes use of the TESS Alert data, which is currently in a beta test phase. The discovery light curve is included in a table inside the arxiv submission