| Alkistis | Zoi Bonanou | National Observatory of Athens | 2012-03-27 | 2012-04-02 |
| Andreas | Zoglauer | University of California-Berkeley | 2008-10-27 | 2008-10-31 |
| Miguel | Zilhao | University of Porto | 2011-04-04 | 2011-05-08 |
| Kuanish | Zhussupbekov | Universitat de Astana | 2012-10-23 | 2012-11-22 |
| Meruyert | Zhassybayeba | Universitat de Astana | 2012-10-23 | 2012-11-22 |
| Qizhou | Zhang | Harvard-Smithsonian Center for Astrophysics, USA | 2012-06-22 | 2012-06-22 |
| Sergio | Zerbini | Universitá degli Studi di Trento | 2007-11-07 | 2007-11-09 |
| Sergio | Zerbini | Università degli Studi di Trento | 2008-12-16 | 2008-12-20 |
| Sergio | Zerbini | Università degli Studi di Trento | 2009-03-01 | 2009-03-05 |
| Sergio | Zerbini | Università di Trento (Itàlia) | 2009-11-10 | 2009-11-13 |
| O.B. | Zaslawskii | Astronomical Institute of Kharkov (Ucrania) | 2008-10-11 | 2008-10-25 |
| Alla | Yurova | Baltic Federal University (Russia) | 2012-05-23 | 2012-06-06 |
| Artyom | Yurov | Kaliningrad State University (Russia) | 2010-03-15 | 2010-03-29 |
| Artem | Yurov | Baltic Federal University (Russia) | 2012-05-23 | 2012-06-06 |
| Ji Ho | Yang | Colegio Retamar de Madrid (CSIC Jovenes Investigadores - Prof. Jose Francisco Romero) | 2011-06-20 | 2011-07-01 |
| Alexej | Weber | Universitat de Heidelberg | 2009-10-04 | 2009-10-16 |
| Tao | Wang | University of Beijing (China) | 2009-11-16 | 2009-11-19 |
| Bin | Wang | Shanghai Jiao-Tong University | 2012-09-26 | 2012-09-26 |
| Joachim | Wambsganss | Zentrum fuer Astronomie der Universitaet Heidelberg | 2008-06-03 | 2008-06-08 |
| Jeff | Wagg | NRAO, Socorro | 2008-04-07 | 2008-04-11 |
