The Scientific results from the orbiting astronomical observatory (OAO-2),

"Proceedings of a symposium sponsored by the National Aeronautics and Space Administration and the American Astronomical Society held in Amherst, Massachusetts, August 23-24, 1971."

Photographic Plate Libraries at European Astronomical Observatories

ACM Computing Classification System (1998): J.2.

Hubble Space Telescope, new & improved.

Mode of access: Internet.

Hubble Space Telescope : update : 18 months in orbit.

Cover title.

Multi-planet extrasolar systems - detection and dynamics

20 years after the discovery of the first planets outside our solar system, the current exoplanetary population includes more than 700 confirmed planets around main sequence stars. Approximately 50% belong to multiple-planet systems in very diverse dynamical configurations, from two-planet hierarchical systems to multiple resonances that could only have been attained as the consequence of a smooth large-scale orbital migration. The first part of this paper reviews the main detection techniques employed for the detection and orbital characterization of multiple-planet systems, from the (now) classical radial velocity (RV) method to the use of transit time variations (TTV) for the identification of additional planetary bodies orbiting the same star. In the second part we discuss the dynamical evolution of multi-planet systems due to their mutual gravitational interactions. We analyze possible modes of motion for hierarchical, secular or resonant configurations, and what stability criteria can be defined in each case. In some cases, the dynamics can be well approximated by simple analytical expressions for the Hamiltonian function, while other configurations can only be studied with semi-analytical or numerical tools. In particular, we show how mean-motion resonances can generate complex structures in the phase space where different libration islands and circulation domains are separated by chaotic layers. In all cases we use real exoplanetary systems as working examples.

The supernova remnant CTB 37B and its associated magnetar CXOU J171405.7-381031: evidence for a magnetar-driven remnant

We discuss the association between the candidate magnetar CXOU J171405.7-381031 and the supernova remnant CTB 37B. The recent detection of the period derivative of the object allowed an estimation of a young characteristic age of only similar to 1000 yr. This value is too small to be compatible even with the minimum radius of the remnant being >= 10 pc, the value corresponding to the lower limit of the estimated distance of 10.2 +/- 3.5 kpc, unless the true distance happens to be even smaller than the lower limit. We argue that a consistent scenario for the remnant`s origin, in which the latter is powered by the energy injected by a young magnetar, is indeed more accurate to explain the young age, and demonstrates its non-standard (i.e. magnetar-driven) nature.

Optimal low cost transfer to L4 and L5 lagrangian points

Lagrangian points L4 and L5 lie at 60 degrees ahead of and behind Moon in its orbit with respect to the Earth. Each one of them is a third point of an equilateral triangle with the base of the line defined by those two bodies. These Lagrangian points are stable for the Earth-Moon mass ratio. Because of their distance electromagnetic radiations from the Earth arrive on them substantially attenuated. As so, these Lagrangian points represent remarkable positions to host astronomical observatories. However, this same distance characteristic may be a challenge for periodic servicing mission. In this work, we introduce a new low-cost orbital transfer strategy that opportunistically combine chaotic and swing-by transfers to get a very efficient strategy that can be used for servicing mission on astronomical mission placed on Lagrangian points L4 or L5. This strategy is not only efficient with respect to thrust requirement, but also its time transfer is comparable to others known transfer techniques based on time optimization. Copyright ©2010 by the International Astronautical Federation. All rights reserved.

Alternative transfer to the Earth-Moon Lagrangian points L4 and L5 using lunar gravity assist

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

Aproximações entre as comunidades científica, amadora e escolar: estudando as potencialidades de observatórios astronômicos para a educação em astronomia

This article considers some potential of activities developed in non-formal education in astronomy, like astronomical observatories and other related establishments. This kind of research is less explored in our country. We present, in this text, a model to study possible relations among these kinds of communities: the scientific, the amateur and the professional, applicable in astronomical observatories, in a motion against the local and punctual activities dispersion and pulverization of these establishments, and against the use of common sense to develop their activities, aiming the advancement of the astronomy education and its national research.

The nature of the companion of PSR J1719-1438: a white dwarf or an exotic object?

We raise the possibility that the very dense, compact companion of PSR J1719-1438, which has a Jupiter-like mass, is an exotic quark object rather than a light helium or carbon white dwarf. The exotic hypothesis naturally explains some of the observed features, and provides quite strong predictions for this system, to be confirmed or refuted in feasible future studies.

Observatory

View of Detroit Observatory from the northwest (University of Michigan). Publication information: Madison Wis. : J. J. Stoner, 1881

The Detroit Observatory of the University of Michigan

Richard Bull, architect. Known at various times as Detroit Observatory, Campus Observatory, Old Observatory. Original image in color

Detroit Observatory

Richard Bull, architect. Known at various times as Detroit Observatory, Campus Observatory, Old Observatory. Image derived from painting of Detroit Observatory by J. A. Cropsey. Color negs: 1479 and 148. On verso: R.D. Palmer, Photographer and Portrait Painter, Huron Street, East of Cook's Hotel. Ann Arbor, Mich.

University of Michigan Observatory

Richard Bull, architect. Known at various times as Detroit Observatory, Campus Observatory, Old Observatory. Observatory from northwest with pine trees and summer garden. On verso: A.L. Colton, Photographer, Ann Arbor, Michigan. Views of the State University a Specialty.

University of Michigan Observatory

Richard Bull, architect. Known at various times as Detroit Observatory, Campus Observatory, Old Observatory.