相关论文: WFIRST Ultra-Precise Astrometry I: Kuiper Belt Obj…

Fast radio bursts (FRBs) represent an exciting frontier in the study of gravitational lensing, due to their brightness, extragalactic nature, and the compact, coherent characteristics of their emission. In a companion work [Kader,…

Preliminary spacecraft trajectories for 45 Kuiper Belt Objects (KBOs) and Pluto suitable for launch between 2025 and 2040 are presented. These 46 objects comprise all objects with H magnitude < 4.0 or which have received a name from the…

Gaudi & Gould (1997) showed that close companions of remote binary systems can be efficiently detected by using gravitational microlensing via the deviations in the lensing light curves induced by the existence of the lens companions. In…

Simultaneous space- and ground-based microlensing surveys, such as K2's Campaign 9 (K2C9) and $WFIRST$, facilitate measuring the masses and distances of free-floating planet (FFP) candidates. FFPs are identified as single-lens events with a…

We present the first search for binary companions of Massive Young Stellar Objects (MYSOs) using AO-assisted $K$ band observations, with NaCo at the VLT. We have surveyed 32 MYSOs from the RMS catalogue, probing the widest companions, with…

The size distribution and total mass of objects in the Oort Cloud have important implications to the theory of planets formation, including the properties of, and the processes taking place in the early solar system. We discuss the…

We simulate the scientific performance of the Wide-Field Infrared Survey Telescope (WFIRST) High Latitude Survey (HLS) on dark energy and modified gravity. The 1.6 year HLS Reference survey is currently envisioned to image 2000 deg$^2$ in…

High resolution imaging is an important tool for follow-up study of exoplanet candidates found via transit detection with the Kepler Mission. We discuss here HST imaging with the WFC3 of 23 stars that host particularly interesting Kepler…

We introduce the BEBOP radial velocity survey for circumbinary planets. We initiated this survey using the CORALIE spectrograph on the Swiss Euler Telescope at La Silla, Chile. An intensive four year observing campaign commenced in 2013,…

We conducted a two-night photometric survey of small Kuiper Belt objects (KBOs) near opposition using the wide-field Hyper Suprime-Cam instrument on the 8.2 m Subaru Telescope. The survey covered about 90 deg^2 of sky, with each field…

Kuiper belt objects smaller than a few kilometers are difficult to observe directly. They can be detected when they randomly occult a background star. Close to the ecliptic plane, each star is occulted once every tens of thousands of hours,…

Recent stellar occultations have allowed accurate instantaneous size and apparent shape determinations of the large Kuiper belt object (50000)~Quaoar and the detection of two rings with spatially variable optical depths. In this paper we…

The WFIRST microlensing mission will measure precise light curves and relative parallaxes for millions of stars, giving it the potential to characterize short-period transiting planets all along the line of sight and into the galactic…

Microlensing is one of the most promising methods of reconstructing the stellar mass function down to masses even below the hydrogen-burning limit. The fundamental limit to this technique is the presence of unresolved binaries, which can in…

While of order a million asteroids have been discovered, the number in rigorously controlled samples that have precise orbits and rotation periods, as well as well-measured colors, is relatively small. In particular, less than a dozen…

We propose a novel means of directly measuring cosmological distances using scintillated microlensing of fast radio bursts (FRBs). In standard strong lensing measurements of cosmic expansion, the main source of systematic uncertainty lies…

We study the effects of an encounter between a wandering cosmic object (WCO) of 0.1 solar mass and some Kuiperian Objects (KO). First, we let the WCO cross the out-skirt of ou Kuiper belt. Such encounters can produce two types of solar…

We present an overview of the ongoing Hubble Space Telescope large program GO-12911. The program is focused on the core of M4, the nearest Galactic globular cluster, and the observations are designed to constrain the number of binaries with…

We present the goals and preliminary results of an unbiased, near-infrared, narrow-band imaging survey of the First Galactic Quadrant (10deg<l<65deg ; -1.3deg<b<+1.3deg). This area includes most of the Giant Molecular Clouds and massive…

Models of the Solar System's dynamical evolution predict the dispersal of primitive planetesimals from their formative regions amongst the gas-giant planets due to the early phases of planetary migration. Consequently, carbonaceous objects…