Related papers: Astrometric signal profile fitting for Gaia
Context. Gaia Early Data Release 3 (Gaia EDR3) provides accurate astrometry for about 1.6 million compact (QSO-like) extragalactic sources, 1.2 million of which have the best-quality five-parameter astrometric solutions. Aims. The proper…
We employ differential astrometric methods to establish a small field reference frame stable at the micro-arcsecond ($\mu$as) level on short timescales using high-cadence simulated observations taken by Gaia in February 2017 of a bright…
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…
The first release of astrometric data from Gaia is expected in 2016. It will contain the mean stellar positions and magnitudes from the first year of observations. For more than 100 000 stars in common with the Hipparcos Catalogue it will…
Astrometric observations with Gaia are expected to play a valuable role in future exoplanet surveys. With current data from Gaia's third data release (DR3), we are sensitive to periods from less than 1 year to more than 4 years but, unlike…
Some ideas for onboard processing and photometry with an astrometry satellite are presented, especially designed for GaiaNIR which may be launched about 2045 as a successor of Gaia. - Increased sensitivity, reduced image overlap, and…
Background. Relative astrometry at or below the micro-arcsec level with a 1m class space telescope has been repeatedly proposed as a tool for exo-planet detection and characterization, as well as for several topics at the forefront of…
We identify stars with large proper motions that are potential candidates for the astrometric microlensing effect during the Gaia mission i.e. between 2012 and 2019. The effect allows a precise measurement of the mass of a single star that…
A significant number of double stars with separations up to 2.5 arcsec are present in the Gaia Data Release 1 astrometric catalogs. Limiting our analysis to a well-studied sample of 1124 doubles resolved by Hipparcos, provided with…
We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in…
Astrometry is less sensitive to stellar activity than the radial velocity technique when attempting to detect Earth mass planets in the habitable zone of solar-type stars. This is due to a smaller number of physical processes affecting the…
The standard errors of the end-of-mission Gaia astrometry have been re-assessed after conclusion of the in-orbit commissioning phase of the mission. An analytical relation is provided for the parallax standard error as function of Gaia G…
In its all-sky survey, Gaia will monitor astrometrically and photometrically millions of main-sequence stars with sufficient sensitivity to brown dwarf companions within a few AUs from their host stars and to transiting brown dwarfs on very…
Astrometric positions of moving objects in the Solar System have been measured using a variety of star catalogs in the past. Previous work has shown that systematic errors in star catalogs can affect the accuracy of astrometric…
GAIA is a short-listed candidate for the ESA Cornerstone mission C5, meeting the ESA Survey Committee requirement for an observatory mission, dedicated to astrometry, providing 10 micro-arcsecond accuracy at 15th magnitude. The GAIA mission…
Gaia Data Release 3 (DR3) provides a wealth of new data products for the astronomical community to exploit, including astrophysical parameters for a half billion stars. In this work we demonstrate the high quality of these data products and…
Accurately measuring stellar parameters is a key goal to increase our understanding of the observable universe. However, current methods are limited by many factors, in particular, the biases and physical assumptions that are the basis for…
The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial…
The highly-accurate optical reference frame GCRF (Gaia Celestial Reference Frame) is expected to be available in several years. By the same time, a new version of radio reference frame ICRF (International Celestial Reference Frame) will be…
With the plentiful information available in the Gaia BP/RP spectra, there is significant scope for applying discriminative models to extract stellar atmospheric parameters and abundances. We describe an approach to leverage an `Uncertain…