Back Circular de la UAI Catalan Circular de la UAI Spanish بخشنامه اتحادیه بینالمللی اخترشناسی Persian Circulaire de l'Union astronomique internationale French Cyrkularz Międzynarodowej Unii Astronomicznej Polish Central Bureau for Astronomical Telegrams#Publicação Portuguese IAU通報 Chinese
The International Astronomical Union Circulars (IAUCs) are notices that give information about astronomical phenomena. IAUCs are issued by the International Astronomical Union's Central Bureau for Astronomical Telegrams (CBAT) at irregular intervals for the discovery and follow-up information regarding such objects as planetary satellites, novae, supernovae, and comets.