Since 1967, the main scientific events of the General Assemblies of the International Astronomical Union have been published in the separate series, Highlights of Astronomy. The present Volume 11 presents the major scientific presentations made at the XXIIIrd General Assembly, August 18-30, 1997, in Kyoto, Japan.
The two volumes (11A + B) contain the text of the three Invited Discourses as well as the proceedings or extended summaries of the 21 Joint Discussions and two Special Sessions held during the General Assembly.

Since 1967, the main scientific events of the General Assemblies of the International Astronomical Union have been published in the separate series, Highlights of Astronomy. The present Volume 11 presents the major scientific presentations made at the XXIIIrd General Assembly, August 18-30, 1997, in Kyoto, Japan.
The two volumes (11A + B) contain the text of the three Invited Discourses as well as the proceedings or extended summaries of the 21 Joint Discussions and two Special Sessions held during the General Assembly.

Since 1967, the main scientific events of the General Assemblies of the International Astronomical Union have been published in the separate series, Highlights of Astronomy. The present Volume 11 presents the major scientific presentations made at the XXIIIrd General Assembly, August 18-30, 1997, in Kyoto, Japan. The two volumes (11A+B) contain the texts of the three Invited Discourses as well as the proceedings or extended summaries of the 21 Joint Discussions and two Special Sessions held during the General Assembly.

It has become a tradition in the Union to publish the Invited Discourses and the Proceedings of the Joint Discussions held at a Gene- ral Assembly in a separate volume entitled HIGHLIGHTS OF ASTRONOMY. This is the fourth volume of its kind and it contains some of the scientific highlights of the Grenoble General Assembly. In order to reduce its size it was decided to publish its content in two separate parts. The part (I) contains the full texts of the In- vited Discourses given by Prof. J.-C. Pecker and by Dr. C. Sagan, and an abstract of Dr. P. Morrison's paper, thus complying with his wish...

Since 1967, the main scientific events of the General Assemblies of the International Astronomical Union have been published in the separate series, Highlights of Astronomy. The present Volume 11 presents the major scientific presentations made at the XXIIIrd General Assembly, August 18-30, 1997, in Kyoto, Japan. The two volumes (11A+B) contain the texts of the three Invited Discourses as well as the proceedings or extended summaries of the 21 Joint Discussions and two Special Sessions held during the General Assembly.

Even the casual reader cannot fail to notice the somewhat uneven presentation of the contributions contributians to this volume, in particular what concerns the st style. yle. A closer scrutiny will also reveal that whereas the English language is certainly the preferred vehicle for commu- nication in astronomy, it is not the mother tongue of all contributors. However, while editing this volume I have felt that it would be more important to assure a speedy publication than to attempt to achieve a high degree of uniformity, which would anyhow be extremely diffi- cult with more than 100...

Ken Freeman I would like to pick out a few items that I found particularly interesting. The choice probably reflects my ignorance, because many of these topics are no doubt more known to most of you. I am fairly sure that some of them are basic and important. We will start with the first session. There were three closely related papers on the evolution of massive stars, the formation of open clusters and associations and the IMF. We learned that clusters appear to form in initially bound clouds 6 of masses between 10'+_10 M , but star formation is a destructive process. Most of the gas is@...

It has become a tradition in the Union to publish the Invited Discourses and the Proceedings of the Joint Discussions held at a Gene ral Assembly in a separate volume entitled HIGHLIGHTS OF ASTRONOMY. This is the fourth volume of its kind and it contains some of the scientific highlights of the Grenoble General Assembly. In order to reduce its size it was decided to publish its content in two separate parts. The part (I) contains the full texts of the In vited Discourses given by Prof. J.-C. Pecker and by Dr. C. Sagan, and an abstract of Dr. P. Morrison's paper, thus complying with his wish...

The scientific meetings of the AU are the AU Symposia, AU Colloquia, Regional Meetings in Astronomy held under the auspices of the AU, the Commission Meetings, which may be Joint Meetings of Commissions, and AU Joint Discussions. This variety means that almost any demand for a meeting can be provided for by the AU structure, pro vided it is international in character, whatever may be the preferences of the proposers. The AU General Assemblies include Co ssion Meetings and Joint Discussions arranged by Commissions, together with the Invited Discourses, and it is these meetings that...

Even the casual reader cannot fail to notice the somewhat uneven presentation of the contributions contributians to this volume, in particular what concerns the st style. yle. A closer scrutiny will also reveal that whereas the English language is certainly the preferred vehicle for commu- nication in astronomy, it is not the mother tongue of all contributors. However, while editing this volume I have felt that it would be more important to assure a speedy publication than to attempt to achieve a high degree of uniformity, which would anyhow be extremely diffi- cult with more than 100...