Data received by observation from astronomic observatory in Belogradchik are used mutually by scientists from Brazil and Chilly. The observatory guarantees accurate observation which is being evaluated on different scientific meeting in Belgium, France, China and others, Observatory Director Lyubomir Iliev said. The Romanian group led by Prof Petre Popesku from the astronomical institute of the Romanian Academy of Science were working together with the Bulgarian astronomers. There were mutual projects with scientists from neighboring countries like Greece, Serbia, Poland, Czech Republic and most often from Romania.