OGLE-2019-BLG-0960 Lb: The Smallest Microlensing Planet

We report the analysis of OGLE-2019-BLG-0960, which contains the smallest mass-ratio microlensing planet found to date (q = 1.2-1.6 × 10-5 at 1s). Although there is substantial uncertainty in the satellite parallax measured by Spitzer, the measurement of the annual parallax effect combined with the finite source effect allows us to determine the mass of the host star (M L = 0.3-0.6 M o?), the mass of its planet (m p = 1.4-3.1 M ?), the projected separation between the host and planet (a ? = 1.2-2.3 au), and the distance to the lens system (D L = 0.6-1.2 kpc). The lens is plausibly the blend, which could be checked with adaptive optics observations. As the smallest planet clearly below the break in the mass-ratio function, it demonstrates that current experiments are powerful enough to robustly measure the slope of the mass-ratio function below that break. We find that the cross-section for detecting small planets is maximized for planets with separations just outside of the boundary for resonant caustics and that sensitivity to such planets can be maximized by intensively monitoring events whenever they are magnified by a factor A \u3e 5. Finally, an empirical investigation demonstrates that most planets showing a degeneracy between (s \u3e 1) and (s \u3c 1) solutions are not in the regime (log s| » 0) for which the close / wide degeneracy was derived. This investigation suggests that there is a link between the close / wide and inner/outer degeneracies and also that the symmetry in the lens equation goes much deeper than symmetries uncovered for the limiting cases

Systematic KMTNet planetary anomaly search. VIII. Complete sample of 2019 subprime field planets

We complete the publication of all microlensing planets (and “possible planets”) identified by the uniform approach of the KMT AnomalyFinder system in the 21 KMT subprime fields during the 2019 observing season, namely, KMT-2019-BLG-0298, KMT-2019-BLG-1216, KMT-2019-BLG-2783, OGLE-2019-BLG-0249, and OGLE-2019-BLG-0679 (planets), as well as OGLE-2019-BLG-0344 and KMT-2019-BLG-0304 (possible planets). The five planets have mean log mass ratio measurements of (−2.6, −3.6, −2.5, −2.2, −2.3), median mass estimates of (1.81, 0.094, 1.16, 7.12, 3.34) M Jup, and median distance estimates of (6.7, 2.7, 5.9, 6.4, 5.6) kpc, respectively. The main scientific interest of these planets is that they complete the AnomalyFinder sample for 2019, which has a total of 25 planets that are likely to enter the statistical sample. We find statistical consistency with the previously published 33 planets from the 2018 AnomalyFinder analysis according to an ensemble of five tests. Of the 58 planets from 2018–2019, 23 were newly discovered by AnomalyFinder. Within statistical precision, half of the planets have caustic crossings, while half do not; an equal number of detected planets result from major- and minor-image light-curve perturbations; and an equal number come from KMT prime fields versus subprime fields

Interface Control in Organic Electronics Using Mixed Monolayers of Carboranethiol Isomers

We employ mixed self-assembled monolayers of carboranethiols to alter the work function of gold and silver systematically. We use isomers of symmetric carboranethiol cage molecules to vary molecular dipole moments and directions, which enable work function tunability over a wide range with minimal alterations in surface energy. Mixed monolayers of carboranethiol isomers provide an ideal platform for the study and fabrication of solution-processed organic field-effect transistors; improved device performance is demonstrated by interface engineering