منابع مشابه
Astrometric Solar-System Anomalies
There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It is increasing by about 15 cm yr−1. The o...
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Micro-arcsec astronomy is able to verify the predictions of theoretical models of gravitation at a level adequate to constraint relevant parameters and select among different formulations. In particular, this concerns the weak field limit applicable to the Sun neighborhood, where competing models can be expressed in a common framework as the Parametrised Post-Newtonian and Parametrised Post-Pos...
متن کاملAstrometric Microlensing Constraints on a Massive Body in the Outer Solar System with the Global Astrometric Interferometer for Astrophysics (GAIA)
A body in Solar orbit beyond the Kuiper belt exhibits an annual parallax that exceeds its apparent proper motion by up to many orders of magnitude. Apparent motion of this body along the parallactic ellipse will deflect the angular position of background stars due to astrometric microlensing (“induced parallax”). By synoptically sampling the astrometric position of background stars over the ent...
متن کاملImpact of Hipparcos Data on Astrometric Reduction of Solar System Bodies
We investigated the improvement of photographic astrometric observations of solar system bodies by use of Hipparcos Catalogue stars, PPM Catalogue stars, and advanced plate reduction procedures. In the plate reductions, we rst computed apparent, topocentric coordinates of the date for the reference stars, taking into account eeects of refraction, aberration , precession, nutation, etc. In this ...
متن کاملThe GAIA astrometric survey of extra-solar planets
The ESA Cornerstone Mission GAIA, to be launched prior to 2012 and with a nominal lifetime of 5 years, will improve the accuracy of Hipparcos astrometry by more than two orders of magnitude. GAIA high-precision global astrometric measurements will provide deep insights on the science of extra-solar planets. The GAIA contribution is primarily understood in terms of the number and spectral type o...
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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2009
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921309990378