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Bucharest Astronomical Observatory celebrated recently its centenary. Its founders were all mathematicians or, better said, astronomers specialized in celestial mechanics. Their first doctoral theses were defended at Sorbonne, in the second half of the 19th century, under the guidance of the greatest specialists of the time. After they returned home, they continued what they had begun in Paris, namely celestial mechanics. The instruments they ordered and the first programmes of astronomical observations had an increasingly closer relation to mathematics, as they referred to astrometry and especially to stellar catalogues. Naturally, there were also astrophysical concerns, timid ones in the beginning, and then ever larger, especially beginning with the International Geophysical Year. The evolution of world astronomy, as well as that of Romania, seems to be following but one direction: astrophysics. The truth is that astrometry and celestial mechanics continue to lie at the basis of all astrophysical researches, actually in an entirely new and modern form. The astrometry schools recently organized, the new astrometry textbooks, as well as the IAU working groups dedicated to modern astrometry prove that the long journey of mathematics and astronomy is not over yet. [ABSTRACT FROM AUTHOR]

In the Astronomical Institute of the Romanian Academy (Bucharest and Cluj observatories) there are 16 600 wide-field plates. Most of the plates were obtained in the frames of astrometric programmes. The plates preserve information especially valuable for analyzing the long-term variations (sometimes more than a century) of the positions, orbits or dimensions of a lot of celestial objects or their pre-discovery history. Archives of selected digitized plates are under preparation in order to propose on-line access to the plate information (preview images for quick plate visualization, as well as real photometric scans). [ABSTRACT FROM AUTHOR]

In the Bucharest Astronomical Observatory we started an observational program aiming at the improvement of positions for optical counterparts of ICRF radiosources by narrow-field CCD observations and the accurate densification of the optical frame and extension to fainter magnitudes. We also estimated the errors in UCAC2, USNO B1.0 and 2MASS catalogs by CCD observations of ICRF sources and we prepared a catalog of intermediary reference stars around ICRF optical counterparts. Comparison with three independent telescope/catalog datasets shows that the precision obtained here represents an important improvement on previous works. [ABSTRACT FROM AUTHOR]

This paper is dedicated to the first comparative study concerning position determinations of selected small bodies in the solar system observed with the Bucharest Observatory equatorial PRIN-MERTZ refractor (d = 0.38m, f = 6.0m) by means of the Carl-Zeiss ASCORECORD measurements and the processing of 5 photographic plates dating from 1971, digitized with the EPSON 1640XL flatbed scanner of the Sofia. The calculations were done with PC computer, with the same program for both cases using a double precision accuracy on the way to compare manual measurements and data processing using the digitized plates. The scan resolution used was 1600 dpi—14 bit grayscale up to 3.6 densities. With this scale 1 pix = 15.875 microns we had the extended field of 15184×15219 pix. The format of the scans was FITS using the standard twain driver for EPSON 1640XL and software developed by S. Mottola. [ABSTRACT FROM AUTHOR]