Mariateresa Crosta

TL;DR: The parsec program as discussed by the authors observed 140 L and T dwarfs on a regular basis from 2007 to 2011, using the WIFI camera on the ESO/2.2 m telescope.

TL;DR: This work, which has recently been extended to better assess the mission performances, has confirmed the previous results and has given indications on how further improve various aspects of the mission profile.

TL;DR: In this paper, the level of reciprocal consistency of two relativistic models, GREM and RAMOD (Gaia, ESA mission), is set to guarantee a physically correct definition of light direction to a star, an essential item for deducing the star coordinates and proper motion within the same level of measurement accuracy.

TL;DR: In this paper, the authors used differential astrometry to construct a small field inertial reference frame stable at the micro-arcsecond level using Gaia measurements of field angles, and they found that the systematic errors are modeled and reliably estimated to the μas level even in fields with a modest number of 37 stars with G < 13 mag over a 0.24 sq. degrees field of view for short timescales of the order of a day for a perfect instrument and with high-cadence observations.

TL;DR: In order to investigate the nature and characteristics of the motions of very faint objects, a flexibly-pointed instrument capable of high astrometric accuracy is an ideal complement to current sky survey telescopes and a unique tool for precision astrophysics as mentioned in this paper.