相关论文: Differential Astrometric Framework for the Jupiter…

Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that…

Individual distances to planetary nebulae are of the utmost relevance for our understanding of post-asymptotic giant-branch evolution because they allow a precise determination of stellar and nebular properties. Also, objects with…

A breakthrough in exoplanet detections is foreseen with the unprecedented astrometric measurement capabilities offered by instrumentation aboard Gaia space observatory. Besides, astrometric discoveries of exoplanets are expected from the…

The presence of Jupiter is crucial to the architecture of the Solar System and models underline this to be a generic feature of planetary systems. We find the detection of the difference between the position and motion recorded by the…

Context: Planetary Nebula distance scales often suffer for model dependent solutions. Model independent trigonometric parallaxes have been rare. Space based trigonometric parallaxes are now available for a larger sample using the second…

We give an assessment of the significance of various known effects which may produce genuine fluctuations of star positions comparable to or larger than Gaia's measurement noise, and which thus may limit the ultimately reachable precision…

We present astrometric observations of the Saturnian satellites Mimas, Enceladus, Tethys, Dione and Rhea from Cassini Imaging Science Subsystem (ISS) narrow-angle camera (NAC) images. Image sequences were designed to observe mutual…

The Hipparcos catalog provides the first epoch of the celestial reference frame (CRF) in the optical domain and serves as an indispensable tool to verify and improve the Gaia CRF for the brighter stars ($V<11$ mag) and to identify the…

The Gaia optical astrometric mission has measured the precise positions of millions of objects in the sky, including extragalactic sources also observed by Very Long Baseline Interferometry (VLBI). In the recent Gaia EDR3 release, an effect…

Given the extreme accuracy of modern space astrometry, a precise relativistic modeling of observations is required. Moreover, the availability of several models formulated in different and independent ways is a security against the presence…

The inference of stellar parameters (such as radius and mass) through asteroseismic forward modelling depends on the number, accuracy, and precision of seismic and atmospheric constraints. ESA's Gaia space mission is providing precise…

We investigate how to quantitatively model the observed differential image motion (DIM) in relative astrometric observations. As a test bed we used differential astrometric observations from the FORS2 camera of the Very Large Telescope…

We use 612 single stars with previously published trigonometric parallaxes placing them within 25 pc to evaluate parallaxes released in Gaia's first data release (DR1). We find that the Gaia parallaxes are, on average, $0.24 \pm 0.02$ mas…

Hipparcos astrometric binaries were observed with the NICI adaptive optics system at Gemini-S, completing the work of Paper I (Tokovinin et al. 2012). Among the 65 F, G, K dwarfs within 67pc of the Sun studied here, we resolve 18 new…

Gaia astrometry of nearby stars is precise enough to detect the tiny displacements induced by substellar companions, but radial velocity data are needed for definitive confirmation. Here we present radial velocity follow-up observations of…

We present the first results of the Astrometric Reconnaissance of Exoplanetary Systems (ARES) project, aimed at validating and characterizing candidate exoplanets around the nearest systems using multi-epoch Hubble Space Telescope (HST)…

Astrometry from the Gaia satellite and from the long-term combination of Hipparcos and Gaia are now sensitive to sky-plane accelerations as low as $\approx$1 m/s/yr. This paper quantifies and explores an important caveat: apparent nonlinear…

We present proper motion (PM) measurements for Draco II, an ultra-faint dwarf satellite of the Milky Way. These PMs are measured using two epochs of Hubble Space Telescope Advanced Camera for Surveys (HST/ACS) imaging separated by a 7 year…

Photometric light curves suffer from fundamental degeneracies that limit surface information recovery. We demonstrate that astrometry enables access to complementary information through photocentre variations induced by rotating surface…

Astrometric measurements are presented for seven nearby stars with previously detected planets: six M dwarfs (GJ 317, GJ 667C, GJ 581, GJ 849, GJ 876, and GJ 1214) and one K dwarf (BD $-$10 3166). Measurements are also presented for six…