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Gliese 86 is a nearby K dwarf hosting a giant planet on a $\approx$16-day orbit and an outer white dwarf companion on a $\approx$century-long orbit. In this study we combine radial velocity data (including new measurements spanning more than a decade) with high angular resolution imaging and absolute astrometry from Hipparcos and Gaia to measure the current orbits and masses of both companions. We then simulate the evolution of the Gl 86 system to constrain its primordial orbit when both stars were on the main sequence; the closest approach between the two stars was then about $9\,$AU. Such a close separation limited the size of the protoplanetary disk of Gl 86 A and dynamically hindered the formation of the giant planet around it. Our measurements of Gl 86 B and Gl 86 Ab's orbits reveal Gl 86 as a system in which giant planet formation took place in a disk truncated at $\approx$2$\,$AU. Such a disk would be just big enough to harbor the dust mass and total mass needed to assemble Gl 86 Ab's core and envelope, assuming a high disk accretion rate and a low viscosity. Inefficient accretion of the disk onto Gl 86 Ab, however, would require a disk massive enough to approach the Toomre stability limit at its outer truncation radius. The orbital architecture of the Gl 86 system shows that giant planets can form even in severely truncated disks and provides an important benchmark for planet formation theory., 17 pages, 10 figures

Because of being in transition or because of choice, many software development environments make use of both the function-oriented and object-oriented approaches in their software development process. In some cases, object-oriented and function-oriented approaches are used in the development of the same system, such as when using function-oriented analysis with object-oriented design, necessitating a transition or mapping from one model to the other. This paper reviews the issues involved in mapping from a function-oriented software model to an object-oriented software model and presents a strategy for accomplishing the mapping in a consistent and partially automatable manner. The effectiveness of the strategy is assessed with four different applications drawn from the literature. It is concluded that the mapping strategy is feasible and reasonably automatable.

This paper reports the results of a field study of the relationship of information flow to the maintainability of COBOL modules in a data processing environment. The study, which considers 238 modules from three different organizations, examines the correlation of information flow metrics and subjective maintainability ratings. Results of the study show that, for the environments included in the study, information flow does have significant correlation with maintainability, and information flow metrics can be used effectively to help identify modules with low (poor) maintainability.

Maps of magnetic field topologies of rapidly rotating stars obtained over the last decade or so have provided unique insight into the operation of stellar dynamos. However, for solar‐type stars many of the targets imaged to date have been lower‐mass zero‐age main sequence stars. We present magnetic maps and differential rotation measurements of two‐higher mass pre‐main sequence stars HD 106506 (∼10 Myrs) and HD 141943 (∼15 Myrs). These stars should evolve into mid/late F‐stars with predicted high differential rotation and little magnetic activity. We investigate what effect the extended convection zones of these pre‐main sequence stars has on their differential rotation and magnetic topologies.

Optical spectra of pre-main sequence flare stars in Orion are presented and analysed by the use of stellar chromospheric models. The stars observed divide into three groups on the basis of their quiescent spectra. The majority of the sample are similar to the dMe stars, with prominent Ca II and Balmer line emission. A second group possesses very strong emission spectra, including He I lines. Stars in third group, however, show little or no emission spectrum. Amongst the emission line stars observed progressively brighter stars exhibit increased Ca II and Balmer line surface fluxes relative to the fainter stars. This trend is also exhibited as a rise in emission line surface fluxes with increasing effective temperature. To analyse this trend a set of non-LTE stellar models were calculated. Using this analysis the trend in line fluxes between stars of different brightness and temperature is interpreted as a spread in the level of chromospheric heating. Furthermore, this trend is interpreted as indicating a spread in the effectiveness of the stellar magnetic dynamos within these stars, perhaps arising from shallowing in their convective layers as they contract to the main sequence.

This paper introduces a new probability distribution based on the H-function of Fox. The distribution is shown to be a generalization of most common “nonnegative” (Pr $\Pr ([X < 0] = 0)$ distributions. Furthermore, it is proved that products, quotients and powers of H-function variates are H-function variates. Several examples are given.

Mississippi State University undertook a remote sensing application project to assist the Mississippi Park Commission in selecting a suitable site for a proposed state park in Adams County, Mississippi. Due to political and geographic constraints, a study area of approximately 130,000 acres was selected. High-altitude color infrared imagery of scale 1 : 120,000 was available, and these data, together with inputs from other sources such as topographic and geologic base maps, yielded the basic data for the construction of a computerized data management system. The cell size for data input was 4 ha. Ten possible areas were selected by modeling and visual evaluation, and after the Commission personnel had selected one site, a low altitude flight was made to obtain 1 : 24,000 color infrared imagery. These data in conjunction with map information were used to develop a data management system for more intensive analysis and modeling on a 1-ha grid. The modeling effort indicated those cells which had the highest suitability for individual recreational activities. Master planning efforts for the park incorporate these data.

This paper describes a project presently underway utilizing remotely sensed data and computer assisted procedures for the location and planning of a new state park. Data was collected on an initial study area of 128,620 acres from which several possible park sites were outlined. After a site was selected, similar procedures were used to outline possible locations for various elements within the park. An iterative design procedure will be used to develop an optimum final design for the park. Included is a detailed discussion of the CAGUP (computer assisted land use planning) package developed to support the planning procedure.