2060 Chiron back to a minimum of brightness

The results of photometric observations of comet/steroid 2060 Chiron at the Observatorio do Pico dos Dias (Brazil - OPD) and the Observatoire de Haute-Provence (France - OHP) during 1994 and 1995 are presented. The analysis of the data shows a decrease of 2060. Chiron brightness from its peak values of 1988-1991. The absolute magnitude, H-V, varies from a maximum of 6.6 in February 1994 up to a minimum of 6.8 in June 1995. Therefore 2060 Chiron is back to a minimum of activity close to that of 1983-1985. The slope parameter G is found to be G = 0.71 +/- 0.15. It is suggested that the H-G magnitude system, generally adopted to present 2060 Chiron brightness, is not the most appropriate due to the cometary activity of this object. Copyright (C) 1996 Elsevier B.V. Ltd.

The brightening of Saturn's F ring

Image photometry reveals that the F ring is approximately twice as bright during the Cassini tour as it was during the Voyager flybys of 1980 and 1981. It is also three times as wide and has a higher integrated optical depth. We have performed photometric measurements of more than 4800 images of Saturn's F ring taken over a 5-year period with Cassini's Narrow Angle Camera. We show that the ring is not optically thin in many observing geometries and apply a photometric model based on single-scattering in the presence of shadowing and obscuration, deriving a mean effective optical depth tau approximate to 0.033. Stellar occultation data from Voyager PPS and Cassini VIMS validate both the optical depth and the width measurements. In contrast to this decades-scale change, the baseline properties of the F ring have not changed significantly from 2004 to 2009. However, we have investigated one major, bright feature that appeared in the ring in late 2006. This transient feature increased the ring's overall mean brightness by 84% and decayed with a half-life of 91 days. (c) 2012 Elsevier B.V. All rights reserved.

La liberalización comercial y los acuerdos de libre comercio: perspectivas ambientales para Centroamérica

Incluye Bibliografía

El seguro agropecuario en México: experiencias recientes

Incluye Bibliografía

Apertura comercial y cambio tecnológico en el Istmo Centroamericano

Incluye Bibliografía

Changes in the urban female labour market

Includes bibliography

The competitive challenge for Brazilian industry

Includes bibliography

How non-traditional are non-traditional exports? The experience of seven countries of the Caribbean Basin

Includes bibliography

Effects of low doses of polyunsaturated fatty acids on the attention deficit/Hyperactivity disorder of children: A systematic review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hélio Oiticica: antropófago de si mesmo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos ergonômicos e sintomas músculo - esqueléticos em descarregadores de caminhão de melancia no Ceasa de Bauru: um estudo de caso

Pós-graduação em Design - FAAC

A estética do desamparo: imagens e narrativas a contrapelo da História

Pós-graduação em Educação - IBRC

O ato de assumir papéis por meio da criação de heterônimo e suas implicações morais

Pós-graduação em Educação - IBRC

Burocracia e pós-graduação Lato Sensu na UNESP: os cursos de especialização em Educação (1999-2010)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A poluição das águas do Rio Bauru vista sob a perspectiva da pedagogia histórico-crítica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)