Showing papers by "Vaughn College of Aeronautics and Technology published in 2008"
Ohio State University1, University of Notre Dame2, University of Warsaw3, Tel Aviv University4, Lawrence Livermore National Laboratory5, Princeton University6, University of Concepción7, University of Cambridge8, Chungbuk National University9, Korea Astronomy and Space Science Institute10, Nagoya University11, Massey University12, University of Auckland13, University of Canterbury14, Victoria University of Wellington15, Konan University16, University of Manchester17, Vaughn College of Aeronautics and Technology18, University of Exeter19, Centre national de la recherche scientifique20, Liverpool John Moores University21, University of St Andrews22, University of Tasmania23, Paul Sabatier University24, Dartmouth College25, University of Oxford26
TL;DR: Two planets with masses that could not have been detected with other techniques are identified; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.
Abstract: Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of ∼0.71 and ∼0.27 times the mass of Jupiter and orbital separations of ∼2.3 and ∼4.6 astronomical units orbiting a primary star of mass ∼0.50 solar mass at a distance of ∼1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.
341 citations
University of Notre Dame1, Massey University2, University of Warsaw3, Nagoya University4, University of Canterbury5, University of Auckland6, Victoria University of Wellington7, Konan University8, University of Manchester9, Vaughn College of Aeronautics and Technology10, University of Concepción11, University of Cambridge12, Institut d'Astrophysique de Paris13, European Southern Observatory14, Heidelberg University15, Paris Diderot University16
TL;DR: In this paper, the authors reported the detection of an extrasolar planet of mass ratio q~2×10-4 in microlensing event MOA-2007-BLG-192.
Abstract: We report the detection of an extrasolar planet of mass ratio q~2×10-4 in microlensing event MOA-2007-BLG-192. The best-fit microlensing model shows both the microlensing parallax and finite source effects, and these can be combined to obtain the lens masses of M=0.060+0.028-0.021 Msolar for the primary and m=3.3+4.9-1.6 M? for the planet. However, the observational coverage of the planetary deviation is sparse and incomplete, and the radius of the source was estimated without the benefit of a source star color measurement. As a result, the 2 ? limits on the mass ratio and finite source measurements are weak. Nevertheless, the microlensing parallax signal clearly favors a substellar mass planetary host, and the measurement of finite source effects in the light curve supports this conclusion. Adaptive optics images taken with the Very Large Telescope (VLT) NACO instrument are consistent with a lens star that is either a brown dwarf or a star at the bottom of the main sequence. Follow-up VLT and/or Hubble Space Telescope (HST) observations will either confirm that the primary is a brown dwarf or detect the low-mass lens star and enable a precise determination of its mass. In either case, the lens star, MOA-2007-BLG-192L, is the lowest mass primary known to have a companion with a planetary mass ratio, and the planet, MOA-2007-BLG-192Lb, is probably the lowest mass exoplanet found to date, aside from the lowest mass pulsar planet.
257 citations
TL;DR: In this paper, a conceptual configuration of the lunar base bioregenerative life support system (LBLSS) including soil-like substrate (SLS) for growing plants is presented.
32 citations
Journal Article•
TL;DR: In this paper, the effect of flow states on the scattering characteristic of plasmas and the interaction of electromagnetic waves with plamas have been analyzed. But the results are significant to the identification, the plasma stealth and the communication of reentry targets.
Abstract: Numerical simulations of chemical reaction flow passing around the reentry target have been carried out with the eleven-element model.The distribution of flow parameters has been obtained for different reentry altitudes and Mach numbers.Based on the results of chemical reaction flow field,with the application of the input impedance method and multilayered medium model,the RCS of the reentry target has been computed using the physical optics method.The effect of flow states on the scattering characteristic has been analyzed.The propagation characteristic of electromagnetic waves in plasmas and the interaction of electromagnetic waves with plasmas have been studied.The results are significant to the identification,the plasmas stealth and the communication of reentry targets.
7 citations
Journal Article•
TL;DR: The concept of system reliability prediction is clarified, the basic process of prediction is analyzed, the prediction method of reliability is summarized, and advantages, disadvantages and applied ranges of these methods are introduced.
7 citations
01 May 2008
Abstract: Abstract The Microlensing Observations in Astrophysics (MOA) is a microlensing survey conducted at Mt. John Observatory in New Zealand. We searched transiting planet candidates from the MOA-I Galactic bulge data, which have been obtained with a 61cm B&C telescope from 2000 to 2005 for a microlensing search. Although this survey data were dedicated to microlensing, they are also quite useful for searching transiting objects because of the large number of stars monitored (~7 million) and the long span of the survey (~6 years). From our analysis, we found 58 transiting planet candidates. We are planning to follow up these candidates with high-precision spectroscopic and photometric observations for further selection, toward the detection of planets by radial velocity observations.
1 citations
Journal Article•
TL;DR: In this article, a finite element analysis model is established to analyze the response of composite laminated plate under low-velocity impact, and the failure criterion of composite materials is adopted to computer different impact damage models, including fiber breakage, matrix failure and delamination, and then stiffness degradation is used to model the failure of composite material.
1 citations
27 May 2008