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• High precision astrometry with closure constraints: the triplet 1803+784/1928+738/2007+777,
  E. Ros, J. M. Marcaide, J.C. Guirado, T.P. Krichbaum, R.A. Preston, M.I. Ratner, I.I. Shapiro, & A. Witzel,
  Vistas in Astronomy, (special issue), Proceedings of the 3rd EVN/JIVE VLBI Symposium, eds. M. Garret & F. Colomer, 41:207-211 (1997)
  [ PDF ] [ PostScript ]
  • Abstract Improvements in the technique of high precision differential astrometry in VLBI based on the use of triangles of radio sources are reported. Such geometry provides new constraints by taking advantage of "closure". Results on the relative separations (ranging from 4.6 to 6.8deg) of the sources in the triangle 1803+784/1928+738/2007+777 from ionosphere-free delays are shown and "sky closure" verified. A comparison with previous results on the pair 1928+738/2007+777 is also presented.

Eduardo Ros ros@mpifr-bonn.mpg.de

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