Welcome to the homepage of the IAU Working Group on Active B Stars and its Be Star Newsletter.

The Working Group on Active B Stars (WGABS) was formed to promote and stimulate research and international collaboration in the field of active B stars. The WGABS is open to all researchers interested in the field.

For an introduction to the features of this site and more details about the WGABS, please see "About this site", for further support or ideas how to improve the site please contact the online editors at This email address is being protected from spambots. You need JavaScript enabled to view it. or drop them in our suggestion box.

Please Note:  We will be gradually updating and refurbishing the web page, beginning with this home page. 

Upcoming: IAU Working Group on Active B Stars Talks

The WG has series of talks, normally held the third Wednesday of each month at 9:00 am Eastern Time (EST), by zoom.  The next talk is scheduled for Wednesday, January 19, 2022.

Seminar organizing committee: Carol Jones, Alex Carciofi, Dietrich Baade, Gregg Wade and Atsuo Okazaki. If have questions or suggestions for the s3eries, please contact the any of the committee members.

Speaker: Dr. Alessia Franchini

Title: Disc eccentricity driving type I and type II outbursts in Be/X-ray binaries

Link: https://westernuniversity.zoom.us/j/98111632482


Be star X-ray binaries are transient systems that show two different types of outbursts. Type I outbursts occur each orbital period while type II outbursts, much brighter, have a period and duration that are not related to any periodicity of the binary system. Observations of these outbursts from different sources show that their characteristics and occurrence depend on the binary orbital properties. In particular, some sources can display type II outburst pairs as well as non-periodic type I outbursts.  In this talk I will present our recent effort to explain these very interesting and peculiar phenomena through the dynamics of eccentric and precessing Be star decretion discs.





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