A dearth of planetary transits in the direction of NGC 6940     

Ben Hood  rew Collier Cameron  Stephen R. Kane  D. M. Bramich  Keith Horne  Rachel A. Street  I. A. Bond  A. J. Penny  Y. Tsapras  A. Quirrenbach  N. Safizadeh  D. Mitchell  J. Cooke 《Monthly notices of the Royal Astronomical Society》2005,360(2):791-800

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Variable stars in the field of open cluster NGC 6819 – II     

R. A. Street  Keith Horne  T. A. Lister  A. Penny  Y. Tsapras  A. Quirrenbach  N. Safizadeh  J. Cooke  D. Mitchell  A. Collier Cameron 《Monthly notices of the Royal Astronomical Society》2005,358(3):795-812

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Results from the Wide Angle Search for Planets Prototype (WASP0) – III. Planet hunting in the Draco field     

Stephen R. Kane †  rew Collier Cameron  Keith Horne  David James  T. A. Lister  Don L. Pollacco  Rachel A. Street  Yiannis Tsapras 《Monthly notices of the Royal Astronomical Society》2005,364(3):1091-1103

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Mapping the line emission distribution of cataclismic variable stars     

T. R. Marsh  K. Horne 《Astrophysics and Space Science》1987,130(1-2):85-89

We describe a method for imaging the accretion disc of a Cataclysmic Variable star. We use the two-dimensional information contained in the line profiles as they vary with phase to invert the line formation process. Asymmetries in the disc, as are caused by the bright-spot, for example, are accounted for naturally.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986.  相似文献   

Echoes from an irradiated disc in GRO J1655–40     

Hynes  O''Brien  Keith Horne  Chen  & Haswell 《Monthly notices of the Royal Astronomical Society》1998,299(4):L37-L41

Oscillations observed in the light curve of Nova V1974 Cygni 1992 since the summer of 1994 have been interpreted as permanent superhumps. From simple calculations based on the tidal disc instability model of Osaki, and assuming that the accretion disc is the dominant optical source in the binary system, we predict that the nova will evolve to become an SU UMa system as its brightness declines from its present value by another 2–3 mag. Linear extrapolation of its current rate of fading (in magnitude units) puts the time of this phase transition within the next 2–4 yr. Alternatively, the brightness decline will stop before the nova reaches that level, and the system will continue to show permanent superhumps in its light curve. It will then be similar to two other old novae, V603 Aql and CP Pup, which still display the permanent superhump phenomenon 80 and 56 yr, respectively, after their eruptions. We suggest that non-magnetic novae with short orbital periods could be progenitors of permanent superhump systems.  相似文献   

基于VRGIS的城市道路交通微观仿真系统研究     

王春  李文  马纯永  韩勇  陈戈  Margaret Horne 《中国海洋大学学报(自然科学版)》2010,40(7)

将GIS技术和虚拟现实技术运用到城市交通仿真系统的微观仿真研究中,在城域景观VRGIS一体化仿真平台基础上建立了城市道路交通微观仿真系统,通过标准化数据模型完成GIS输入交通仿真数据,利用VR技术实现交通仿真的三维可视化,以一种人机交互模式实现虚拟城市环境中的交通微观仿真。该系统用于英国纽卡斯尔市中心重建项目的方案评价中,通过对3种规划方案的优劣对比,为交通管理部门提供一定的决策支持。  相似文献   

The statistics of natural ELF/VLF waves derived from a long continuous set of ground-based observations at high latitude     

A.J. Smith  R.B. Horne  N.P. Meredith 《Journal of Atmospheric and Solar》2010,72(5-6):463-475

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Analysis of the oscillations in HST observations of the quiescent SU UMa type dwarf nova WZ Sagittae     

Warren Skidmore  William F. Welsh  Janet H. Wood  M. S. Catalán  Keith Horne 《Monthly notices of the Royal Astronomical Society》1999,310(3):750-758

An analysis of the UV oscillations in WZ Sge is presented, in which we obtain the oscillation amplitude spectra. We find a strong 27.9-s oscillation in our Hubble Space Telescope ( HST ) UV and zeroth-order light curves as well as weaker oscillations at 28.4 s in the UV and 29.1 s in the zeroth order. We find that the main oscillation amplitude spectrum can be fitted with static white dwarf spectra of about 17 000 K, an accretion hotspot of only a few 100 K hotter than the underlying white dwarf temperature or a variety of cool (<14 500 K) white dwarf pulsation amplitude spectra. A pulsating white dwarf can also explain the very blue colour of oscillations of different periods previously found in the optical. Comparing our results with those of Welsh et al., we see that the amplitude spectra of the main oscillations in WZ Sge measured with different periods in data sets from different epochs are similar to each other. Our results raise questions about using the magnetically accreting rotating white dwarf model to explain the oscillations. We suggest that the pulsating white dwarf model is still a viable explanation for the oscillations in WZ Sge.  相似文献   

A comparative review of commercially-available software for soil slope stability analysis     

J. Oliphant  R. M. Horne 《Geotechnical and Geological Engineering》1992,10(4):321-344

Summary The main purpose of this paper is to carry out a comparative review of four commercial computer programs for the stability analysis of soil slopes. The review is carried out in two parts and should prove useful for potential users of the software. Part I reviews the facilities offered in terms of the range of limit equilibrium methods, the geotechnical modelling abilities, the operational features and the supporting documentation, and includes a general impression of friendliness. Part II assesses the use, accuracy and validity of each program by presenting and discussing the results of a number of model tests. Also included is a brief discussion of slope stability analysis, in particular the limit equilibrium method. The requirements of a practical computer program for soil slope stability analysis are defined and then used as a means of assessing the effectiveness of each program.  相似文献   

HST and ground-based eclipse observations of V2051 Ophiuchi: binary parameters     

Raymundo Baptista  M. S. Catalán  Keith Horne  & D. Zilli 《Monthly notices of the Royal Astronomical Society》1998,300(1):233-243

We report on high-speed eclipse photometry of the dwarf nova V2051 Oph while it was in a low brightness state, at B  ≃ 16.2 mag. In comparison with the average IUE spectra, the ultraviolet continuum and emission lines appear reduced by factors of, respectively, ≃ 4 and ≃ 5. Flickering activity is mostly suppressed and the light curve shows the eclipse of a compact white dwarf at the disc centre which contributes ≃ 60 per cent of the total light at 3900–4300 Å. We use measurements of contact phases in the eclipse light curve to derive the binary geometry and to estimate masses and relevant dimensions. We find a mass ratio of q  = 0.19 ± 0.03 and an inclination of i  = 83 ± 2°. The masses of the component stars are M ₁ = 0.78 ± 0.06 M⊙ and M ₂ = 0.15 ± 0.03 M⊙. Our photometric model predicts K ₁ = 83 ± 12 km s⁻¹ and K ₂ = 436 ± 11 km s⁻¹. The predicted value of K₁ is in accordance with the velocity amplitude obtained from the emission lines after a correction for asymmetric line emission in the disc is made. The secondary of V2051 Oph is significantly more massive than the secondaries of the other ultrashort period dwarf novae. V2051 Oph is probably a relatively young system, with a secondary star that has not had enough time to evolve out of thermal equilibrium.  相似文献