Showing papers by "Vaughn College of Aeronautics and Technology published in 2011"
Ohio State University1, University of Warsaw2, Princeton University3, Chungbuk National University4, European Southern Observatory5, University of Tasmania6, Massey University7, Texas A&M University8, Korea Astronomy and Space Science Institute9, University of Exeter10, University of St Andrews11, Liverpool John Moores University12, Royal Society13, Max Planck Society14, Las Cumbres Observatory Global Telescope Network15, University of California, Santa Barbara16, Queen Mary University of London17, Nagoya University18, University of Notre Dame19, University of Auckland20, University of Canterbury21, Victoria University of Wellington22, Konan University23, Vaughn College of Aeronautics and Technology24, Institut d'Astrophysique de Paris25, University of Toulouse26, University of Texas at Austin27, Heidelberg University28, Lawrence Livermore National Laboratory29, University of Rijeka30, University of Vienna31, NASA Exoplanet Science Institute32, Space Telescope Science Institute33
TL;DR: In this article, the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations is presented, made possible by a confluence of two relatively unusual circumstances.
Abstract: We present the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible by a confluence of two relatively unusual circumstances. First, the binary lens is bright enough (I = 15.6) to permit Doppler measurements. Second, we measure not only the usual seven binary-lens parameters, but also the "microlens parallax" (which yields the binary mass) and two components of the instantaneous orbital velocity. Thus, we measure, effectively, six "Kepler+1" parameters (two instantaneous positions, two instantaneous velocities, the binary total mass, and the mass ratio). Since Doppler observations of the brighter binary component determine five Kepler parameters (period, velocity amplitude, eccentricity, phase, and position of periapsis), while the same spectroscopy yields the mass of the primary, the combined Doppler + microlensing observations would be overconstrained by 6 + (5 + 1) – (7 + 1) = 4 degrees of freedom. This makes possible an extremely strong test of the microlensing solution. We also introduce a uniform microlensing notation for single and binary lenses, define conventions, summarize all known microlensing degeneracies, and extend a set of parameters to describe full Keplerian motion of the binary lenses.
187 citations
Konan University1, Chungbuk National University2, University of Notre Dame3, Nagoya University4, Las Cumbres Observatory Global Telescope Network5, Niels Bohr Institute6, University of Washington7, Ohio State University8, University of Canterbury9, University of Toulouse10, Charles University in Prague11, Goddard Space Flight Center12, Institut d'Astrophysique de Paris13, University of Maryland, College Park14, Massey University15, Princeton University16, European Southern Observatory17, University of St Andrews18, University of Auckland19, Victoria University of Wellington20, University of Manchester21, Vaughn College of Aeronautics and Technology22, Texas A&M University23, Tel Aviv University24, Korea Astronomy and Space Science Institute25, Weizmann Institute of Science26, University of Exeter27, Liverpool John Moores University28, Massachusetts Institute of Technology29, University of Tasmania30, University of Rijeka31, Vienna University of Technology32, Space Telescope Science Institute33, University College London34, Heidelberg University35, University of Cape Town36, Graduate University for Advanced Studies37, Istituto Nazionale di Fisica Nucleare38, Ames Research Center39, University of Salerno40, University of Göttingen41, Aarhus University42, Sharif University of Technology43, Keele University44, University of Warsaw45, University of Cambridge46, University of Concepción47
TL;DR: In this article, the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method, is presented.
Abstract: We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method. This planet has a mass of mp = 10.4 +/- M(Earth) and orbits a star of Mstar = 0.56 +/- 0.09 M(Sun) at a semi-major axis of a = 3.2 + 1.9/-0.5 AU, and an orbital period of 7.6 +7.7/-1.5 yrs. The planet and host star mass measurements are due to the measurement of the microlensing parallax effect. This measurement was primarily due to the orbital motion of the Earth, but the analysis also demonstrates the capability measure micro lensing parallax with the Deep Impact (or EPOXI) spacecraft in a Heliocentric orbit. The planet mass and orbital distance are similar to predictions for the critical core mass needed to accrete a substantial gaseous envelope, and thus may indicate that this planet is a failed gas giant. This and future microlensing detections will test planet formation theory predictions regarding the prevalence and masses of such planets
150 citations
Nagoya University1, Princeton University2, Ohio State University3, University of California, Santa Barbara4, Las Cumbres Observatory Global Telescope Network5, University of Notre Dame6, Queen Mary University of London7, University of Canterbury8, Massey University9, University of Toulouse10, University of St Andrews11, Chungbuk National University12, Max Planck Society13, Niels Bohr Institute14, University of Göttingen15, University of Auckland16, Victoria University of Wellington17, Konan University18, Vaughn College of Aeronautics and Technology19, Texas A&M University20, Weizmann Institute of Science21, Tel Aviv University22, Technion – Israel Institute of Technology23, Korea Astronomy and Space Science Institute24, Chungnam National University25, University of Valencia26, Auckland University of Technology27, California Institute of Technology28, University of Exeter29, European Southern Observatory30, Liverpool John Moores University31, University of Salerno32, Ames Research Center33, University of Stuttgart34, Aarhus University35, Armagh Observatory36, University of Copenhagen37, Heidelberg University38, Sharif University of Technology39, Keele University40, Institut d'Astrophysique de Paris41, University College London42, University of Tasmania43
TL;DR: In this paper, the authors reported the 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.
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.
54 citations
TL;DR: A new solution of azimuth compression together with motion compensation is presented here by taking the advantages of GEOSAR movement, and a new method to overcome the Earth curvature in range compression of EACH footprint is testified.
13 citations
01 Jan 2011
TL;DR: In this article, the effect of temperature on hybrid woven composite panels (100mm×100mm/25mm) which underwent drop-weight impact at five different test temperatures: -60°C, -20°C; room temperature, 75°C and 125°C.
Abstract: This paper investigates the effect of temperature on hybrid woven composite panels (100mm×100mm×25mm) which underwent drop-weight impact at five different test temperatures: -60°C, -20°C, room temperature, 75°C and 125°C. The studies were conducted by using experimental and 3-D dynamic finite element approaches. The specimens tested were made of plain-weave hybrid S2 glass and IM7 graphite fibers imbedded in toughened epoxy (cured at 177°C). The composite panels were impacted using an instrumented drop-weight impact tester. The time-histories of impact-induced dynamic strains and impact forces were recorded. The damaged specimens were inspected visually and using the ultrasonic C-scan method.
5 citations
01 Jan 2011
TL;DR: In this paper, the standard tensile tests were conducted following ASTM Standards D3039 (Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials) and D3518 (standard test method for In-Plane Shear Response of PolyMER Matrix Composite materials by Tensile Test of a ±45° Laminate), on non-hybrid plain weave composite materials.
Abstract: Monotonic tensile tests were conducted following ASTM Standards D3039 (Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials) and D3518 (Standard Test Method for In-Plane Shear Response of Polymer Matrix Composite Materials by Tensile Test of a ±45° Laminate), on non-hybrid plain weave composite materials. Strips (6.35mm×25mm×250mm) of non-hybrid IM-7 Graphite/SC-79 epoxy called GR for short, non-hybrid S-2 Glass/SC-79 epoxy called GL for short specimens were tensile tested. The tests were conducted at -60°C, -20°C, 75°C and 125°C. The Poisson’s ratios were measured using strain gages. It was observed that temperature had a small effect on the Poisson’s ratio.
3 citations
01 Jan 2011
TL;DR: In this paper, the Young's and shear moduli of the composite materials were calculated using the rule of mixtures and compared to those obtained experimentally using the experimental values obtained from the stress-strain curves of composite materials.
Abstract: Monotonic tensile tests were conducted following ASTM Standards D3039 (Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials) and D3518 (Standard Test Method for In-Plane Shear Response of Polymer Matrix Composite Materials by Tensile Test of a ??45° Laminate), on hybrid and non-hybrid plain weave composite materials. Strips of non-hybrid IM-7 Graphite/SC-79 epoxy called GR for short, non-hybrid S-2 Glass/SC-79 epoxy called GL for short, hybrid GR/GL/GR and hybrid GL/GR/GL specimens were tensile tested. The tests were conducted at –60°C, –20°C, room temperature, 75°C and 125°C. The rule of mixtures was used to predict the Young’s moduli of GL/GR/GL and GR/GL/GR using the experimental values obtained from the stress-strain curves of the GL and GR specimens. The predicted Young’s moduli of GL/GR/GL and GR/GL/GR were then compared to those obtained experimentally. It was found that the calculated Young’s and shear moduli match closely (within 6 %) to those obtained experimentally.
3 citations
01 Jan 2011
TL;DR: In this article, the effect of temperature on the ballistic limit of hybrid woven composite panels (6in×4in×0.25in) at three different temperatures: R.T, 75°C and 125°C was investigated.
Abstract: This paper investigates the effect of temperature on the ballistic limit of hybrid woven composite panels (6in×4in×0.25in) at three different temperatures: R.T, 75°C and 125°C. Studies were also done on the stacking sequence and its effect on the ballistic limit at the above stated temperature. The studies were conducted by combining experimental and 3-D dynamic finite element approaches. The specimens tested were made of plain-weave hybrid S2 glass-IM7graphite fibers/toughened epoxy. The composite panels were impacted using an in-house gas gun. The time-histories of impact-induced dynamic strains was recorded. The damaged specimens were inspected visually and using the ultrasonic C-scan method. A 3-D dynamic finite element (FE) software, with Chang-Chang composite damage model, was then used to simulate the experimental results of the ballistic impact tests. Good agreement between experimental and FE results has been achieved.Copyright © 2011 by ASME
1 citations