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Points: A Global Reference Frame Opportunity

Published online by Cambridge University Press:  19 July 2016

J.F. Chandler  and
R.D. Reasenberg
J.F. Chandler
Affiliation:
Smithsonian Astrophysical Observatory 60 Garden Street Cambridge, Massachusetts 02138 USA
R.D. Reasenberg
Affiliation:
Smithsonian Astrophysical Observatory 60 Garden Street Cambridge, Massachusetts 02138 USA

Abstract

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POINTS is a space-based optical astrometric interferometer, capable of measuring the angular separation of two stars about 90° apart with 5-microarcsec (μas) nominal accuracy. During the intended ten-year mission, a repeated survey of a few hundred targets over the whole sky, including a few bright quasars, will establish a “rigid” reference grid with 0.5 μas position uncertainties. At that level, the grid will be free of regional biases and tied to the extra-Galactic frame that is our present best candidate for an inertial frame. POINTS will also determine parallaxes and annual proper motions at about the same level. Further, the planetary ephemeris frame will be tied through stellar aberration to the grid at about 300 μas. Additional targets of interest, to a limiting magnitude of greater than 20, will be observed relative to the grid, yielding determinations with uncertainties depending on the observing schedule. Measurement at the microarcsec/year level of the apparent relative velocities of quasars that are widely separated on the sky will severely test the assumption of cosmological quasar distances and may also constrain models of the early Universe.

Type
Part 3: Concepts, Definitions, Models
Information
Symposium - International Astronomical Union , Volume 141: Inertial Coordinate System on the Sky , 1990 , pp. 217 - 228
Copyright
Copyright © Kluwer 1990 

References

Bartel, N., Herring, T.A., Ratner, M.I., Shapiro, I.I., and Corey, B.E. (1986). VLBI limits on the proper motion of the ‘core’ of the superluminal quasar 3C345, Nature 319, 733–738.CrossRefGoogle Scholar
Eichhorn, H. (1974). Astronomy of Star Positions (Frederick Ungar Publishing, NY).Google Scholar
Field, G. (1990). Private communication.Google Scholar
Fricke, W. et al., (1988). Veröffentl. Astron. Rechen-Institut , Heidelberg, N. 32.Google Scholar
Johnston, K.J., de Vegt, C., Florkowski, D.R., and Wade, C.M. (1985). Astron. J. 90, 2390.CrossRefGoogle Scholar
Kovalevsky, J. (1984). Sp. Sci. Rev. 39, 1–63.CrossRefGoogle Scholar
Podobed, V.V. (1965). Fundamental Astrometry , Translated from the Russian by Vyssotsky, A. N., The University of Chicago Press.Google Scholar
Reasenberg, R.D. et al. (1988a). Astron. J. 96, 1731.CrossRefGoogle Scholar
Reasenberg, R.D., Babcock, R.W., Chandler, J.F., and Shapiro, I.I. (1988b). In Proceedings of the International Symposium on Experimental Gravitational Physics , edited by Enke, Hu and Michelson, P. Google Scholar
Veron-Cetty, M.-P., and Veron, P. (1987). “A Catalog of Quasars and Active Nuclei”, ESO Scientific Report No. 5 (Garching:ESO).Google Scholar