Related papers: Planet Parameters in Microlensing Events
Spitzer microlensing parallax observations of OGLE-2015-BLG-1212 decisively breaks a degeneracy between planetary and binary solutions that is somewhat ambiguous when only ground-based data are considered. Only eight viable models survive…
Despite the detection of a large number of gravitational microlensing events, the nature of Galactic dark matter remains very uncertain. This uncertainty is due to two major reasons: the lens parameter degeneracy in the measured Einstein…
We estimate the fraction of mass that is composed of compact objects in gravitational lens galaxies. This study is based on microlensing measurements (obtained from the literature) of a sample of 29 quasar image pairs seen through 20 lens…
Hundreds of gravitational microlensing events have now been detected towards the Galactic bulge, with many more to come. The detection of fine structure in these events has been theorized to be an excellent way to discover extra-solar…
Microlensing is a powerful tool for studying stellar atmospheres because as the source crosses regions of formally infinite magnification (caustics) the surfaceof the star is resolved, thereby allowing one to measure the radial intensity…
We present microlensing planet OGLE-2017-BLG-0173Lb, with planet-host mass ratio either $q\simeq 2.5\times 10^{-5}$ or $q\simeq 6.5\times 10^{-5}$, the lowest or among the lowest ever detected. The planetary perturbation is strongly…
We classify various types of planetary lensing signals and the channels of detecting them. We estimate the relative frequencies of planet detections through the individual channels with special emphasis on the new channels to be…
It has been argued that the power spectrum of the anisotropies in the Cosmic Microwave Background (CMB) may be effectively degenerate, namely that the observable spectrum does not determine a unique set of cosmological parameters. We…
By monitoring $10^6$ quasars one could search for lensing by stars and Massive Compact Halo Objects (Machos) out to redshifts $z\sim 4$. If Machos have a present cosmological density $\Omega_{L,0}=1\%$, then the expected event rate is…
The mass-sheet degeneracy is a well-known problem in gravitational lensing which limits our capability to infer astrophysical lens properties or cosmological parameters from observations. As the number of gravitational wave observations…
Follow-up observations of high-magnification gravitational microlensing events can fully exploit their intrinsic sensitivity to detect extrasolar planets, especially those with small mass ratios. To make followup more uniform and efficient,…
We show that Earth mass planets orbiting stars in the Galactic disk and bulge can be detected by monitoring microlensed stars in the Galactic bulge. The star and its planet act as a binary lens which generates a lightcurve which can differ…
We investigate the effect of a finite source on the planetary-lensing signals of high-magnification events. From this, we find that the dependency of the finite-source effect on the caustic shape is weak and perturbations survive even when…
Four planets have recently been discovered by gravitational microlensing. The most recent of these discoveries is the lowest-mass planet known to exist around a normal star. The detection of planets in gravitational microlensing events was…
We present the observations and analysis of a high-magnification microlensing planetary event, KMT-2022-BLG-0440, for which the weak and short-lived planetary signal was covered by both the KMTNet survey and follow-up observations. The…
The microlens parallax is a crucial observable for conclusively identifying the nature of lens systems in microlensing events containing or composed of faint (even dark) astronomical objects such as planets, neutron stars, brown dwarfs, and…
The Nancy Grace Roman Space Telescope will expand the reach of gravitational microlensing surveys by increasing the number of events monitored and the precision of their light curves. We investigate Roman's ability to detect triple-lens…
Extra-solar planets can be efficiently detected in gravitational microlensing events of high magnification. High accuracy photometry is required over a short, well-defined time interval only, of order 10-30 hours. Most planets orbiting the…
We follow the microlensing approach and quantify the occurrence of Kepler exoplanets as a function of planet-to-star mass ratio, q, rather than planet radius or mass. For planets with radii ~1-6 R_earth and periods <100 days, we find that,…
The Einstein rings and proper motions of nearby stars tend to be large. Thus, every year some foreground stars within a few hundred parsecs of Earth induce gravitational lensing events in background stars. In some of these cases, the events…