Issue |
A&A
Volume 373, Number 1, July I 2001
|
|
---|---|---|
Page(s) | 336 - 344 | |
Section | Atomic, molecular, and nuclear data | |
DOI | https://doi.org/10.1051/0004-6361:20010499 | |
Published online | 15 July 2001 |
General relativistic satellite astrometry
II. Modeling parallax and proper motion
1
Istituto di Fisica "G. Galilei" , Via Marzolo 1, 35100 Padova, Italy e-mail: fernando.defelice@pd.infn.it; alberto.vecchiato@pd.infn.it
2
Osservatorio Astronomico di Torino, Strada Osservatorio 20, 10025 Pino Torinese To, Italy e-mail: bucc@to.astro.it
Corresponding author: M. G. Lattanzi, lattanzi@to.astro
Received:
24
March
2000
Accepted:
22
March
2001
The non-perturbative general relativistic approach to
global astrometry introduced by de Felice et al. ([CITE])
is here extended to account for the star motions on the
Schwarzschild celestial sphere. A new expression of the
observables, i.e. angular distances among stars, is provided,
which takes into account the effects of parallax and proper
motions. This dynamical model is then tested on an end-to-end
simulation of the global astrometry mission GAIA. The results
confirm the findings of our earlier work, which applied to the
case of a static (angular coordinates only) sphere. In particular,
measurements of large arcs among stars (each measurement good to
~arcsec, as expected for
mag
stars) repeated over an observing period comparable to the mission
lifetime foreseen for GAIA, can be modeled to yield estimates of
positions, parallaxes, and annual proper motions good to ~
arcsec. This second round of experiments confirms,
within the limitations of the simulation and the assumptions of
the current relativistic model, that the space-born global
astrometry initiated with Hipparcos can be pushed down to the
10-5 arcsec accuracy level proposed with the GAIA
mission. Finally, the simplified case we have solved can be used
as reference for testing the limiting behavior of more realistic
models as they become available.
Key words: relativity / astrometry / methods: data analysis / space vehicles
© ESO, 2001
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