1,798 research outputs found
SET-E: The Search for Extraterrestrial Environmentalism
There is currently no evidence for life on any known exoplanet. Here, we
propose a form of "galactic anthropology" to detect not only the existence of
life on transiting exoplanets, but also the existence of environmentalism
movements. By observing the planet's atmosphere over long time baselines, the
destruction and recovery of a hole in an exoplanet's ozone layer may be
observable. While not readily detectable for any one system with JWST, by
binning together observations of hundreds of systems we can finally determine
the occurrence rate of environmental movements on Earthlike planets in the
galaxy, a number we term eta-Green-Earth.Comment: 4 pages, 2 figures, Comments Welcom
Reaction rates of graphite with ozone measured by etch decoration
Etch-decoration technique of detecting vacancies in graphite has been used to determine the reaction rates of graphite with ozone in the directions parallel and perpendicular to the layer planes. It consists essentially of peeling single atom layers off graphite crystals without affecting the remainder of the crystal
Model-Independent Stellar and Planetary Masses from Multi-Transiting Exoplanetary Systems
Precise exoplanet characterization requires precise classification of
exoplanet host stars. The masses of host stars are commonly estimated by
comparing their spectra to those predicted by stellar evolution models.
However, spectroscopically determined properties are difficult to measure
accurately for stars that are substantially different from the Sun, such as
M-dwarfs and evolved stars. Here, we propose a new method to dynamically
measure the masses of transiting planets near mean-motion resonances and their
host stars by combining observations of transit timing variations with radial
velocity measurements. We derive expressions to analytically determine the mass
of each member of the system and demonstrate the technique on the Kepler-18
system. We compare these analytic results to numerical simulations and find the
two are consistent. We identify eight systems for which our technique could be
applied if follow-up radial velocity measurements are collected. We conclude
this analysis would be optimal for systems discovered by next generation
missions similar to TESS or PLATO, which will target bright stars that are
amenable to efficient RV follow-up.Comment: 9 pages, 1 figure, submitted to Ap
Analytical techniques for determining boron in graphite
Two analytical techniques, a gold nucleation and an etch-decoration technique have been developed for determining the presence and mobility of boron in graphite
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