منابع مشابه
High Precision Differential Astrometry
While conventional imaging in VLBI provides information only about the relative position between different features of a given source, phase-referenced observations can provide precise positional information with respect to an external reference. The use of differential techniques relies on the fact that most of the instrumental and propagation effects are common for radio sources sufficiently ...
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We observed the pair of radio sources 1150+812 and 1803+784 in November 1993 with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. We determined the angular separation between the two sources with submilliarcsecond accuracy by using differential techniques. This result demonstrates the feasibility of high precision differential astrometry for radio sources separated in the sky by almo...
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Uppaal is a tool suitable for model checking real-time systems described as networks of timed automata communicating by channel synchronizations and extended with integer variables. Its first version was released in 1995 and its development is still very active. It now features an advanced modelling language, a user-friendly graphical interface, and a performant model checker engine. In additio...
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Orbital solutions for binary or multiple stellar systems that combine astrometry (e.g., position angles and angular separations) with spectroscopy (radial velocities) have important advantages over astrometric-only or spectroscopic-only solutions. In many cases they allow the determination of the absolute masses of the components, as well as the distance. Yet, these kinds of combined solutions ...
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Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery of nearly all extrasolar systems known today. While the most successful method thus far is the radial velocity technique, new interferometric instruments lik...
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ژورنال
عنوان ژورنال: New Astronomy Reviews
سال: 1999
ISSN: 1387-6473
DOI: 10.1016/s1387-6473(99)00059-7