¹ Departamento de Física, Escuela Politécnica Superior, Universidad de Jaén, C/Virgen de la Cabeza, 2, E-23071 Jaén, Spain
² National Astronomical Observatory Rozhen, PO Box 136, BG-4700 Smoljan, Bulgaria

A remarkable correlation between the H emission line and the radio behaviour of LS I+61°303 (V615 Cas, GT 0236+610) over its 4 yr modulation is discovered. The radio outburst peak is shifted by a quarter of the 4 yr modulation period (about 400 days) with respect to the equivalent width of the H emission line variability. The onset of the LS I+61°303 radio outbursts varies in phase with the changes of the H emission line, at least during the increase of H equivalent width. This is the first clear correlation between the emission associated to the compact object and the Be circumstellar disk in a Be/X-ray binary system.

Accepted by Astronomy and Astrophysics Letters
Preprints from rzamanov@ujaen.es
or on the web at http://xxx.lanl.gov/abs/astro-ph/0005201