Related papers: Astrometric accuracy during the past 2000 years
The Sixth Catalogue of Fundamental Stars (FK6) combines the ground-based astrometric data of the basic fundamental stars, obtained over more than two centuries and summarized in the FK5, with the observations of the HIPPARCOS astrometry…
Context: Stellar occultations, greatly enhanced by the publication of the Gaia data releases, permit not only the determination of asteroid size and shape, but also the retrieval of additional, accurate astrometry, with a possible relevant…
I review the current status of cosmology as emerging from recent observations of cosmic microwave background anisotropies as well as from other sources of cosmological information.
Precision measurements of the stars in short-period orbits around the supermassive black hole at the Galactic Center are now being used to constrain general relativistic effects, such as the gravitational redshift and periapse precession.…
The apparent positions of planets are determined by means of the fundamental ephemerides, the precession-nutation models of the Earth, the gravitational effects and aberrations et al. Around 2000, many astrometrical conceptions, models and…
We observed the pair of radio sources 1150+812 and 1803+784 in November 1993 with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. We determined the angular separation between the two sources with submilliarcsecond accuracy by…
The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred…
The {\Gaia} astrometric mission was approved by the European Space Agency in 2000 and the construction of the spacecraft and payload is on-going for a launch in late 2012. {\Gaia} will continuously scan the entire sky for 5 years, yielding…
In this article we identify and discuss various statistical and systematic effects influencing the astrometric accuracy achievable with MICADO, the near-infrared imaging camera proposed for the 42-metre European Extremely Large Telescope…
High-precision astrometry well beyond the capacities of Gaia will provide a unique way to achieve astrophysical breakthroughs, in particular on the nature of dark matter, and a complete survey of nearby habitable exoplanets. In this…
The GRAVITY instrument on the ESO VLTI pioneers the field of high-precision near-infrared interferometry by providing astrometry at the $10 - 100\,\mu$as level. Measurements at such high precision crucially depend on the control of…
URAT1 is an observational, astrometric catalog covering most of the Dec >= -15 deg area and a magnitude range of about R = 3 to 18.5. Accurate positions (typically 10 to 30 mas standard error) are given for over 228 million objects at a…
Johannes Hevelius's 1662 Mercurius in Sole Visus Gedani contains a table of magnitudes and apparent telescopic diameters of nineteen stars. The data conform to a simple model, suggesting that Hevelius produced what is essentially a table of…
We examine the historical development of astrophysical science in Antarctica from the early 20th century until today. We find three temporally overlapping eras, each having a rather distinct beginning. These are the astrogeological era of…
This paper introduces two astronomical methods developed through computational simulation to evaluate the historical dating of ancient astronomical sources. The first identifies a 1151-year planetary cycle based on the recurrence of visible…
Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in the near infrared a sample of 12 binary and multiple stars and one open cluster. We used the near diffraction limited images of these systems to…
This is the dawning of the age of precision cosmology, when all the important parameters will be established to one significant figure or better, within the cosmological model. In the age of accurate cosmology the model, which nowadays…
A first version of the Twin Astrographic Catalog (TAC) of positions for 705,679 stars within $-18^{\circ} \le \delta \le 90^{\circ}$ has been produced. The sky coverage of the TAC is complete to over 90\% in that area. The limiting…
Large area surveys will dominate the forthcoming decades of astronomy and their success requires characterizing thousands of discoveries through additional observations at higher spatial or spectral resolution, and at complementary cadences…
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…