Search Publications
No fundamental-mode pulsation in R Leonis ?
Tuthill, P. G.; Feast, M. W.; Haniff, C. A. +1 more
We present new and precise angular diameter measurements of the long-period variable R Leonis at 833 and 903 nm. Our inferred photospheric diameter (38±2.5 mas) and stellar effective temperature (2459 + 150 K) are both in good agreement with recent determinations made at the same variability phase in the near-infrared. Assuming a parallax of 8.3 m…
Proper motion study of the globular cluster M 3
Tucholke, H. -J.; Scholz, R. -D.; Brosche, P.
We present proper motions for stars in the field of the galactic globular cluster NGC 5272 (M 3). This study forms part of the Bonn programme of globular cluster proper motions. 14 plates were taken with the Bonn double refractor, spanning epoch differences of up to 85 years. Relative proper motions for all well-measurable stars in the 1.5deg x 1.…
Variable Stars with the HIPPARCOS Satellite
Eyer, L.; Mignard, F.; Grenon, M. +2 more
We present the photometric results of Hipparcos satellite for the first 1.5 year of the mission. For this period, the satellite gave numerous (20 to 120) photometric measurements of 120000 stars. More precisely, we describe: the precision, the capability to find periods with respect to the specific sampling of the satellite (based on simulated dat…
Physical studies of asteroids. XXVIII. Lightcurves and photoelectric photometry of asteroids 2, 14, 51, 105, 181, 238, 258, 369, 377, 416, 487, 626, 679, 1048 and 2183
Erikson, A.; Albrecht, R.; Schober, H. J. +5 more
Photoelectric photometry of 15 mainbelt asteroids was carried out at ESO, La Silla, Chile with the 0.50 m ESO, the 0.60 m Bochum, the 0.90 m Dutch and 1.0 m ESO telescopes, at CTIO, Chile with the 0.60 m Lowell and 1.0 m telescopes, and at OHP, France with 1.0 m telescope at Mt. Chiran. We have derived new rotation periods and present composite li…
Classification of the HIPPARCOS Input Catalogue Using the Kohonen Network
Hernandez-Pajares, M.; Floris, J.
The unsupervised classification with respect to stellar populations of 106 000 of the 118 000 Hipparcos input catalogue stars is presented, in terms of angular position and velocity, apparent magnitude and spectral type. The classification is performed first by merging the real data with a small sample of synthetic stars, which are representative …
Orbits of Six Visual Double Stars
Docobo, J. A.; Ling, J. F.; Prieto, C.
New orbits have been calculated for the visual double stars WDS 04262N3443, WDS 07573N0108, WDS 08214S0136, WDS 08267N2433, WDS 19549N5049, and WDS 20232N2052 using recent observations. Dynamic parallaxes and masses have been calculated.
A preliminary list of stars from TYCHO observations
Bastian, U.; van Leeuwen, F.; Petersen, C. +6 more
The final Tycho Catalog will be a major source of astrometric standard stars when it will be published, in 1997. While the Tycho positions with their full accuracy will only be available at the end of the data reduction, it is already possible to derive a preliminary list of about one million stars from the Tycho Input Catalogue (TIC) which have a…
The rotor: A new method to derive rotation between two reference frames
Vityazev, V. V.
The paper presents a study of two techniques to derive the relative orientation of two reference frames: the Standard Method, based on the least squares procedure, and a new method - the ROTOR, based on the representation of systematic differences in terms of orthogonal functions. It is shown that the ROTOR is preferable over the Standard Method s…
High-Precision VLBI Astrometric Observations of Radio-Emitting Stars for Detection of Extra-Solar Planets
Preston, Robert A.; Jones, Dayton L.; Lestrade, Jean-Francois +1 more
The displacement of a radio-emitting star around the barycenter of a possible planetary system can be measured by astrometric very long baseline interferometry (VLBI) observations. We have observed the radio-emitting starσ2 CrB at 8 epochs over 5 years by VLBI and fitted its 5 astrometric parameters to the observed coordinates. The post…
Progress report on the radial velocity measurement programme of Population II stars.
Bartkevičius, A.; Sperauskas, J.
The Population II radial velocity measurement programme was started in 1988 and was carried out during six observing runs. Metal-deficient stars, components of Population II visual binaries or common proper motion pairs, suspected radial velocity variables, HIPPARCOS programme stars are included into the observing programme. The measurements were …