We welcome today with special joy the presence among us of scholars who have come from all parts of the world to our small State of Vatican City, to study the Spectral Classification of the Stars. We know that, in the spirit of collaboration, you will confer together on the topics proposed by the International Astronomical Union. We thank you for the honour of your presence and we are glad of this opportunity to show our continued interest in Science and particularly in Astronomy; this interest leads us to maintain the Vatican Observatory and to support our esteemed Academy of Sciences.