Abstract. The present status of the Kyiv meridian axial circle after its refurbishment is described. The mounting of a new micrometer with the front-illuminated CCD 1040×1160 allows to observe stars up to V = 16 mag. For the stars of 11-14 mag, the internal positional accuracy of a single observation is 0.05-0.10 , and stellar V values are determined with an accuracy of 0.03-0.06 mag. The project of observations of star fields in the direction of 209 extragalactic radio-sources in declination zone 0+30 • is now in progress. The catalogue of positions, magnitudes and proper motions of secondary reference stars in regions with ICRF sources is expected to be compiled by 2003. Another project under way is a long-term astrometric survey of the equatorial zone to extend the Hipparcos-Tycho frame to fainter stars, and to measure their magnitudes and V − R colours.

нацiонального унiверситету iменi Тараса Шевченка В данiй роботi було проведено чисельне моделювання еволюцiї орбiт 34-х об'єктiв групи Кентаврiв i 2-х вiддалених комет групи Юпiтера-39Р/Отерма та 29Р/Швассмана-Вахмана 1 iз використанням метода Еверхарта. В результатi були отриманi еволюцiйнi треки елементiв орбiт 33-х Кентаврiв i 3-х комет (95Р/Хiрон, 29Р/Швассманна-Вахманна 1 i 39Р/Отерма) на 1 мiльйон рокiв в минуле та майбутнє. Проведено статистичний аналiз результатiв чисельного iнтегрування, виявленi тренди в змiнах орбiт Кентаврiв в минулому та майбутньому. Визначена частка Кентаврiв, котрi потенцiйно можуть проявити себе як комети, за значеннями розподiлiв перигелiйних вiдстаней промодельованих орбiт. Показано, що Кентаври можуть переходити на орбiти комет родини Юпiтера, i навпаки. Кентаври є одним iз можливих джерел для поповнення популяцiї комет родини Юпiтера, але необхiднi також й iншi джерела.

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The long-term orbital evolution modeling of 95P/Chiron (2060) is discussed with its implication to the physical evolution of this representative of Centaurs group. In this work we have carried out the orbital evolution modeling for 33 objects of Centaurs population, and for 2 distant Jupiter-family comets 39P/Oterma and 29P/Schwassmann-Wachmann 1. The calculations were produced for 1 million years backward and forward from the present time. The Everhart implicit single sequence methods for integrating orbits were used. Due to discovered cometary activity in 2060 Chiron it is of interest to reveal Centaurs modeled orbits with small perihelion distances. Such orbits could lead to "waking up" of cometary nature in some Centaurs. The modeled orbital evolution patterns of Centaurs are analyzed and the fraction of potential candidates to comets are discussed.