相关论文: A Precision test of Hipparcos systematics towards …

We show that the errors in the Hipparcos parallaxes towards the Pleiades and the Hyades open clusters are spatially correlated over angular scales of 2 to 3 deg, with an amplitude of up to 2 mas. This correlation is stronger than expected…

We present absolute trigonometric parallaxes and relative proper motions for three members of the Pleiades star cluster, obtained with HST's Fine Guidance Sensor 1r, a white-light interferometer. We estimate spectral types and luminosity…

We use absolute trigonometric parallaxes from the Hipparcos Catalogue to determine individual distances to members of the Hyades cluster, from which the 3-dimensional structure of the cluster can be derived. Inertially-referenced proper…

Radial motions of stars in nearby moving clusters are determined from accurate proper motions and trigonometric parallaxes, without any use of spectroscopy. Assuming that cluster members share the same velocity vector (apart from a random…

An improved method for estimating distances to open clusters is presented and applied to Hipparcos data for the Pleiades and the Hyades. The method is applied in the context of the historic Pleiades distance problem, with a discussion of…

The internal velocity structure in the Hyades cluster as seen by Hipparcos is compared with realistic N-body simulations using the NBODY6 code, which includes binary interaction, stellar evolution and the Galactic tidal field. The model…

New memberships, mean parallaxes and proper motions of all 9 open clusters closer than 300 pc (except the Hyades) and 9 rich clusters between 300 and 500 pc have been computed using Hipparcos data. Precisions, ranging from 0.2 to 0.5 mas…

Hipparcos parallaxes fix distances to individual stars in the Hyades cluster with an accuracy of 6%. We use the Hipparcos (and Tycho-2) proper motions, which have a larger relative precision than the trigonometric parallaxes, to derive ~3…

Aims: We provide a new distance estimate for the Pleiades based on the moving cluster method, which will be useful to further discuss the so-called Pleiades distance controversy and compare it with the very precise parallaxes from the Gaia…

We present absolute parallaxes and proper motions for seven members of the Hyades open cluster, pre-selected to lie in the core of the cluster. Our data come from archival astrometric data from FGS 3, and newer data for 3 Hyads from FGS 1R,…

The mean parallax of the Pleiades open cluster from the Hipparcos catalog is larger than the true value by approximately 1 mas. The origin of this error, as well as a possible algorithm of correcting it, was proposed by Makarov (2002). The…

Trigonometric parallax observations made with the Hubble Space Telescope's Fine Guidance Sensor #3 (HST FGS) of seven Hyades Cluster members in six fields of view have been analyzed along with their proper motions to determine the distance…

Context. In the absence of complete kinematic data it has not previously been possible to furnish accurate lists of member stars for all moving groups. There has been an unresolved dispute concerning the apparent inconsistency of the…

A new reduction of the astrometric data as produced by the Hipparcos mission has been published, claiming that the accuracies for nearly all stars brighter than magnitude $\mathrm{Hp}=8$ are improved, by up to a factor 4, compared to the…

In this paper we investigate whether a misestimate of proper motions could have been a source of substantial systematic errors in the statistical parallax determination of the absolute magnitude of RR Lyrae stars. In an earlier paper, we…

We have used new parallax measurements, obtained by the Hipparcos satellite, of fifteen nearby, metal-poor stars to re-define the subdwarf main-sequence. All of these stars have parallaxes determined to an accuracy of at least 12 %.…

Hipparcos parallax measurements of stars in the Pleiades notoriously result in a cluster distance of 118 pc; ~10% shorter than the `classical' results of MS-fitting. In an earlier paper we developed a purely empirical MS-fitting method to…

The Hipparcos data allow a major step forward in the research of `moving groups' in the Solar neighbourhood, as the common motion of group members causes converging proper motions. Previous knowledge on these coherent structures in velocity…

We present further arguments that the Hipparcos parallaxes for some of the clusters and associations represented in the Hipparcos catalog should be used with caution in the study of the Galactic structure. It has been already shown that the…

More than two hundred classical cepheids were measured by the Hipparcos astrometric satellite, making possible a geometrical calibration of the cepheid distance scale. However, the large average distance of even the nearest cepheids…