Double Mertz-Repsold refractor-astrograph of Kyiv university

Current status of the Astronomical Observatory of Kyiv National University (AO KNU, KAO) archive of photographic observations. According to preliminary estimates AO KNU glass collection contains about 20 thousand photographic plates. At present, in the primary mode of identifying and systematization about 4500 shots (65% of them are glass plates, others - large-format films) are partially cataloged. For the convenience of pre-cataloging approximately 200 sets of observations has been allocated, which are unevenly distributed in the timeline.

Most of the series include pictures of the photometric standards obtained on the same date. In the case of comets, exhibited by different methods, calibration images were obtained. Most plates have dimensions of 13 x 18, 13 x 13 and 16 x 16 cm, the maximum size of plates - 30 x 30 cm, the minimum (calibration ones)- 9 x 6 cm. The collection includes also some secondary images, achieved by the contact method, but their accuracy needs to be investigated as well as the accuracy of slides, obtained from plates of large size. On plates emulsions of more than 40 types were identified.

In 2010, efforts were undetaken to bring the KAO archive data of plates, which were received during the period 1898-1946 and are of historical value, in accordance with standards of IVOA.

The problems encountered during the organizing and cataloging of AO KNU glass collection are next:

• due to two evacuations of the observatory during the WWII, not the entire archive of glass had survived, so the identification of pictures from observational logs, publications and AO KNU reports often hard to be done;
• observations were made with more than 40 instruments, some of them no longer exist;
• for a fairly long observation period (almost a hundred years - 1898-1996) the form of information records changed essentially many times, and some important observations are not decipherable;
• not all observational logs are preserved.

Distribution of KAO observations in timeline

In 2010 the efforts in KAO plate collection including into Joint Database of ukrainian glass archives on the basis of MAO NASU computational facilities have started. Test digital images of near 100 historical plates were obtained with Microteck 9800 flatbed scanner and estimation of possible positional and photometric accuracies which could be reached from digital images of KAO plate collection has been conducted. The accuracy studying gives the very encouraging results of 100 mas in positions and 0.07 in magnitudes.

Plate obtained in May 1912 with Jupiter expositions	Plate obtained in June 1941 with Solar disk and spots on it	Plate obtained in Oct 1974 with comet imaget