Journal club is a popular activity in astronomy departments abroad. People usually bring lunch to eat or something to drink. Its major purpose is to share information on recent publications, and give the speaker an opportunity to practice presentation. Thus, it’s extremely benificial to students and is mostly a student activity.
Everyone can either present one of papers of our interests, or some works we have completed or even uncompleted. To save our time, one choose a paper which everyone is already reading but has not fully understood. By talking about it, all may have a better perspective on the topic.
(From Xu W’s email)