Huug van Woerden has been one of the giants of Dutch astronomy. He was part of the development of Radio Astronomy in the Netherlands, from the very beginning, and was one of the key person behind the huge success of the Westerbork Telescope in Groningen in the 1970's and 1980's. Huug, blessed with a huge amount of energy, has been active as an amateur astronomer during his whole career, and has led the KNVWS for many years. He laid the foundations of the current Kapteyn Institute, witnessing the growth of the institute from about 10 people when he started to the current number of about 100. On top of that he is an excellent scientist, who worked both in the radio and the optical regime.

We are blessed to be able to celebrate on August 31, 2016, Huug's 90th birthday! To celebrate this, a mini-symposium will be organized about the topics of Huug's interest. The mini-symposium will take place at the Zernike campus in Groningen and start at 12PM with a lunch, followed by the symposium. Details about the mini-symposium are given at https://www.astro.rug.nl/huug90/. Attendance is free, if you register at https://www.astro.rug.nl/huug90/registration.html.

Hoping to meet you at this happy occasion,

Reynier Peletier, Jan Willem Pel, Lucia van der Voort and Martine ter Wal, on behalf of the Kapteyn Institute.