The Theory of Brown Dwarfs and Extrasolar Giant Planets

Straddling the traditional realms of the planets and the stars, objects below the edge of the main sequence have such unique properties, and are being discovered in such quantities, that one can rightly claim that a new field at the interface of planetary science and and astronomy is being born. In this review, we explore the essential elements of the theory of brown dwarfs and giant planets, as well as of the new spectroscopic classes L and T. To this end, we describe their evolution, spectra, atmospheric compositions, chemistry, physics, and nuclear phases and explain the basic systematics of substellar-mass objects across three orders of magnitude in both mass and age and a factor of 30 in effective temperature. Moreover, we discuss the distinctive features of those extrasolar giant planets that are irradiated by a central primary, in particular their reflection spectra, albedos, and transits. Aspects of the latest theory of Jupiter and Saturn are also presented. Throughout, we highlight the effects of condensates, clouds, molecular abundances, and molecular/atomic opacities in brown dwarf and giant planet atmospheres and summarize the resulting spectral diagnostics. Where possible, the theory is put in its current observational context.Comment: 67 pages (including 36 figures), RMP RevTeX LaTeX, accepted for publication in the Reviews of Modern Physics. 30 figures are color. Most of the figures are in GIF format to reduce the overall size. The full version with figures can also be found at: http://jupiter.as.arizona.edu/~burrows/papers/rm

JIRAM, the Jovian Infrared Auroral Mapper

JIRAM is an imager/spectrometer on board the Juno spacecraft bound for a polar orbit around Jupiter. JIRAM is composed of IR imager and spectrometer channels. Its scientific goals are to explore the Jovian aurorae and the planet's atmospheric structure, dynamics and composition. This paper explains the characteristics and functionalities of the instrument and reports on the results of ground calibrations. It discusses the main subsystems to the extent needed to understand how the instrument is sequenced and used, the purpose of the calibrations necessary to determine instrument performance, the process for generating the commanding sequences, the main elements of the observational strategy, and the format of the scientific data that JIRAM will produce

Leiderschap in verandering

Leidinggevenden zijn bij een organisatieverandering zowel een zeer belangrijke faal- alsslaagfactor. Niet alleen moeten managers leidinggeven aan een verandering, ze zijn zelfook vaak voorwerp van verandering. Dit vergt een dubbelrol van leidinggevenden.Organisaties doen veel aan het definiëren van de – voor de verandering – gewenste rolvan leidinggevenden, maar vaak blijft dit hangen in jargon en kretologie. Uit onderzoeksresultaten blijkt dat er aanzienlijke discrepanties bestaan tussen percepties van leidinggevenden en medewerkers. Leidinggevenden menen zelf aan het wensbeeld te voldoen, terwijl medewerkers weinig verandering in leiderschap ervaren. Bovendien blijktuit dit onderzoek dat gewenst leiderschap niet altijd het meest effectief is. Het artikelgeeft mogelijke oorzaken voor deze uitkomsten, en schetst op basis hiervan hoe de tweerollen van leidinggevenden bij verandering zich tot elkaar verhouden. Het vervullen vande twee rollen vereist dat leidinggevenden eerst zelf veranderen, zodat ze vervolgensanderen kunnen leiden. Hiertoe dienen leidinggevenden inzicht te krijgen in hun eigenfunctioneren

Competence Development and Appraisal in Organizations

Contains fulltext : 138636.pdf (publisher's version ) (Open Access)This contribution focuses on the way in which employees and managers perceive themselves and each other. Based on two PhD-projects, one in which differences between self-ratings and supervisor ratings have been studied, and one in which the focus was the differences between team leaders' self-perception and the team members' perception, it was concluded that supervisors and employees have a different view on the competencies and behavior of one another. Some explanations for these results are given. Also, implications for competence development and appraisal of employees and managers will be described.17 p