Vaughn College of Aeronautics and Technology

About: Vaughn College of Aeronautics and Technology is a education organization based out in New York, New York, United States. It is known for research contribution in the topics: Gravitational microlensing & Planetary system. The organization has 727 authors who have published 708 publications receiving 14082 citations. The organization is also known as: College of Aeronautics.

MOA 2010-BLG-477Lb: Constraining the Mass of a Microlensing Planet from Microlensing Parallax, Orbital Motion, and Detection of Blended Light

Abstract: Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA 2010-BLG-477. The measured planet-star mass ratio is q = (2.181 {+-} 0.004) Multiplication-Sign 10{sup -3} and the projected separation is s = 1.1228 {+-} 0.0006 in units of the Einstein radius. The angular Einstein radius is unusually large {theta}{sub E} = 1.38 {+-} 0.11 mas. Combining this measurement with constraints on the 'microlens parallax' and the lens flux, we can only limit the host mass to the range 0.13 < M/M{sub Sun} < 1.0. In this particular case, the strong degeneracy between microlensing parallax and planet orbital motion prevents us from measuring more accurate host and planet masses. However, we find that adding Bayesian priors from two effects (Galactic model and Keplerian orbit) each independently favors the upper end of this mass range, yielding star and planet masses of M{sub *} = 0.67{supmore » +0.33}{sub -0.13} M{sub Sun} and m{sub p} = 1.5{sup +0.8}{sub -0.3} M{sub JUP} at a distance of D = 2.3 {+-} 0.6 kpc, and with a semi-major axis of a = 2{sup +3}{sub -1} AU. Finally, we show that the lens mass can be determined from future high-resolution near-IR adaptive optics observations independently from two effects, photometric and astrometric.« less

A SUB-SATURN MASS PLANET, MOA-2009-BLG-319Lb

Abstract: We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K- or M-dwarf star in the inner Galactic disk or Galactic bulge. The high-cadence observations of the MOA-II survey discovered this microlensing event and enabled its identification as a high-magnification event approximately 24 hr prior to peak magnification. As a result, the planetary signal at the peak of this light curve was observed by 20 different telescopes, which is the largest number of telescopes to contribute to a planetary discovery to date. The microlensing model for this event indicates a planet-star mass ratio of q = (3.95 ± 0.02) × 10–4 and a separation of d = 0.97537 ± 0.00007 in units of the Einstein radius. A Bayesian analysis based on the measured Einstein radius crossing time, t E, and angular Einstein radius, θE, along with a standard Galactic model indicates a host star mass of M L = 0.38+0.34 –0.18 M ☉ and a planet mass of M p = 50+44 –24 M ⊕, which is half the mass of Saturn. This analysis also yields a planet-star three-dimensional separation of a = 2.4+1.2 –0.6 AU and a distance to the planetary system of D L = 6.1+1.1 –1.2 kpc. This separation is ~2 times the distance of the snow line, a separation similar to most of the other planets discovered by microlensing.

Improving the prospects for detecting extrasolar planets in gravitational microlensing events in 2002

Abstract: Gravitational microlensing events of high magnification have been shown to be promising targets for detecting extrasolar planets. However, only a few events of high magnification have been found using conventional survey techniques. Here we demonstrate that high-magnification events can be readily found in microlensing surveys using a strategy that combines high-frequency sampling of target fields with on-line difference imaging analysis. We present 10 microlensing events with peak magnifications greater than 40 that were detected in real-time towards the Galactic bulge during 2001 by the Microlensing Observations in Astrophysics (MOA) project. We show that Earth-mass planets can be detected in future events such as these through intensive follow-up observations around the event peaks. We report this result with urgency as a similar number of such events are expected in 2002.

The ASLIB CRANFIELD RESEARCH PROJECT ON The COMPARATIVE EFFICIENCY OF INDEXING SYSTEMS

Abstract: The Aslib Cranfield Project had its beginning some years back, when several members of the Aslib Aeronautical Group took an active part in the development of a new form of index that had been proposed by the National Aeronautical Institute of Holland. Later we did some tests on the Uniterm system of co‐ordinate indexing and, following a joint conference with the Classification Research Group, the idea developed of making a complete test of various indexing systems. A draft programme was prepared and was considered by many people in this country and the United States. An application was made to the National Science Foundation for a grant to cover the first stage of the investigation, and in July 1957 the Foundation advised Aslib that the grant had been approved.