22 research outputs found
The TESS Triple-9 Catalog II: a new set of 999 uniformly-vetted exoplanet candidates
The Transiting Exoplanet Survey Satellite (TESS) mission is providing the
scientific community with millions of light curves of stars spread across the
whole sky. Since 2018 the telescope has detected thousands of planet candidates
that need to be meticulously scrutinized before being considered amenable
targets for follow-up programs. We present the second catalog of the Plant
Patrol citizen science project containing 999 uniformly-vetted exoplanet
candidates within the TESS ExoFOP archive. The catalog was produced by fully
exploiting the power of the Citizen Science Planet Patrol project. We vetted
TESS Objects of Interest (TOIs) based on the results of Discovery And Vetting
of Exoplanets DAVE pipeline. We also implemented the Automatic Disposition
Generator, a custom procedure aimed at generating the final classification for
each TOI that was vetted by at least three vetters. The majority of the
candidates in our catalog, TOIs, passed the vetting process and were
labelled as planet candidates. We ruled out candidates as false positives
and flagged as potential false positives. Our final dispositions and
comments for all the planet candidates are provided as a publicly available
supplementary table.Comment: 17 pages, 11 figures, 5 tables. Accepted for publication on MNRA
Mesoscale Convective System Surface Pressure Anomalies Responsible for Meteotsunamis Along the U.S. East Coast on June 13th, 2013
Two destructive high-frequency sea level oscillation events occurred on June 13th, 2013 along the U.S. East Coast. Seafloor processes can be dismissed as the sources, as no concurrent offshore earthquakes or landslides were detected. Here, we present evidence that these tsunami-like events were generated by atmospheric mesoscale convective systems (MCSs) propagating from inland to offshore. The USArray Transportable Array inland and NOAA tide gauges along the coast recorded the pressure anomalies associated with the MCSs. Once offshore, the pressure anomalies generated shallow water waves, which were amplified by the resonance between the water column and atmospheric forcing. Analysis of the tidal data reveals that these waves reflected off the continental shelf break and reached the coast, where bathymetry and coastal geometry contributed to their hazard potential. This study demonstrates that monitoring MCS pressure anomalies in the interior of the U.S. provides important observations for early warnings of MCS-generated tsunamis
Transient Kinetic Experiments within the High Conversion Domain: The Case of Ammonia Decomposition
In the development of catalytic materials, a set of standard conditions is needed where the kinetic performance of many samples can be compared. This can be challenging when a sample set covers a broad range of activity. Precise kinetic characterization requires uniformity in the gas and catalyst bed composition. This limits the range of convecting devices to low conversion (generally <20%). While steady-state kinetics offer a snapshot of conversion, yield and apparent rates of the slow reaction steps, transient techniques offer much greater detail of rate processes and hence more information as to why certain catalyst compositions offer better performance. In this work, transient experiments in two transport regimes are compared: an advecting differential plug flow reactor (PFR) and a pure-diffusion temporal analysis of products (TAP) reactor. The decomposition of ammonia was used as a model reaction to test three simple materials: polycrystalline iron, cobalt and a bimetallic preparation of the two. These materials presented a wide range of activity and it was not possible to capture transient information in the advecting device for all samples at the same conditions while ensuring uniformity. We push the boundary for the theoretical estimates of uniformity in the TAP device and find reliable kinetic measurement up to 90% conversion. However, what is more advantageous from this technique is the ability to observe the time-dependence of the reaction rate rather than just singular points of conversion and yield. For example, on the iron sample we observed reversible adsorption of ammonia and on cobalt materials we identify two routes for hydrogen production. From the time-dependence of reactants and product, the dynamic accumulation was calculated. This was used to understand the atomic distribution of H and N species regulated by the surface of different materials. When ammonia was pulsed at 550 °C, the surface hydrogen/nitrogen, (H/N), ratios that evolved for Fe, CoFe and Co were 2.4, 0.25 and 0.3 respectively. This indicates that iron will store a mixture of hydrogenated species while materials with cobalt will predominantly store NH and N. While much is already known about iron, cobalt and ammonia decomposition, the goal of this work was to demonstrate new tools for comparing materials over a wider window of conversion and with much greater kinetic detail. As such, this provides an approach for detailed kinetic discrimination of more complex industrial samples beyond conversion and yield
The TESS Triple-9 Catalog: 999 uniformly vetted candidate exoplanets
The Transiting Exoplanet Survey Satellite (TESS) has detected thousands of
exoplanet candidates since 2018, most of which have yet to be confirmed. A key
step in the confirmation process of these candidates is ruling out false
positives through vetting. Vetting also eases the burden on follow-up
observations, provides input for demographics studies, and facilitates training
machine learning algorithms. Here we present the TESS Triple-9 (TT9) catalog --
a uniformly-vetted catalog containing dispositions for 999 exoplanet candidates
listed on ExoFOP-TESS, known as TESS Objects of Interest (TOIs). The TT9 was
produced using the Discovery And Vetting of Exoplanets pipeline, DAVE, and
utilizing the power of citizen science as part of the Planet Patrol project.
More than 70% of the TOIs listed in the TT9 pass our diagnostic tests, and are
thus marked as true planetary candidates. We flagged 144 candidates as false
positives, and identified 146 as potential false positives. At the time of
writing, the TT9 catalog contains ~20% of the entire ExoFOP-TESS TOIs list,
demonstrates the synergy between automated tools and citizen science, and
represents the first stage of our efforts to vet all TOIs. The DAVE generated
results are publicly available on ExoFOP-TESS.Comment: 15 pages, 11 figures. Accepted on MNRA