相关论文: Gaia: focus, straylight and basic angle

We use methods of differential astrometry to construct a small field inertial reference frame stable at the micro-arcsecond level. Such a high level of astrometric precision can be expected with the end-of-mission standard errors to be…

The second data release of ESA's Gaia satellite (Gaia DR2) revolutionised astronomy by providing accurate distances, proper motions, apparent magnitudes, and in many cases temperatures and radial velocities for an unprecedented number of…

We discuss the impact that Gaia, a European Space Agency (ESA) cornerstone mission that has been in scientific operations since July 2014, is expected to have on the definition of the cosmic distance ladder and the study of resolved stellar…

The ESA global astrometry space mission Gaia has been monitoring the position of a billion stars since 2014. The analysis of such a massive dataset is challenging in terms of the data processing involved. In particular, the blind detection…

Surface brightness asymmetries are a very common feature of stars. Among other effects they cause a difference between the projected barycentre and photocentre. The evolution of those surface features makes this difference time-dependent.…

Estimating a distance by inverting a parallax is only valid in the absence of noise. As most stars in the Gaia catalogue will have non-negligible fractional parallax errors, we must treat distance estimation as a constrained inference…

Over the course of several years, stars trace helical trajectories as they traverse across the sky due to the combined effects of proper motion and parallax. It is well known that the gravitational pull of an unseen companion can cause…

Context. The Gaia satellite will measure highly accurate absolute parallaxes of hundreds of millions of stars by comparing the parallactic displacements in the two fields of view of the optical instrument. The requirements on the stability…

(Abridged) A consequence of the Earth's motion with respect to the CMB is that over a 10 year period it will travel a distance of ~800 AU. As first noted by Kardashev in 1986, this baseline can be used to carry out astrometric measurements…

The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Gaia Data Release 2 (DR2) contains the observations of a selected sample of 14,099…

The Gaia mission is described, along with its scientific potential and its updated science perfomances. Although it is often described as a self-calibrated mission, Gaia still needs to tie part of its measurements to external scales (or to…

A tool for representation of the one-dimensional astrometric signal of Gaia is described and investigated in terms of fit discrepancy and astrometric performance with respect to number of parameters required. The proposed basis function is…

In its all-sky survey, Gaia will monitor astrometrically hundreds of thousands of main-sequence stars within $\approx200$ pc, looking for the presence of giant planetary companions within a few AUs from their host stars. Indeed, Gaia…

Scope of this contribution is twofold. First, it describes the potential of the global astrometry mission Gaia for detecting and measuring planetary systems based on detailed double-blind mode simulations and on the most recent predictions…

The second Gaia data release (GDR2) provides precise five-parameter astrometric data (positions, proper motions and parallaxes) for an unprecedented amount of sources (more than $1.3$ billion, mostly stars). The use of this wealth of…

Gaia is the cornerstone mission of the European Space Agency. From late 2013 it will start collecting superb astrometric, photometric and spectroscopic data for around a billion of stars of our Galaxy. While surveying the whole sky down to…

The GAIA astrometric mission has recently been approved as one of the next two `cornerstones' of ESA's science programme, with a launch date target of not later than mid-2012. GAIA will provide positional and radial velocity measurements…

A gravitational wave (GW) passing through an astrometric observer causes periodic shifts of the apparent star positions measured by the observer. For a GW of sufficient amplitude and duration, and of suitable frequency, these shifts might…

Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of the entire sky. Aims: We present the Gaia Science Alerts project, which has been in…

The European Space Agency Gaia satellite was launched into orbit around L2 in December 2013. This ambitious mission has strict requirements on residual systematic errors resulting from instrumental corrections in order to meet a design goal…