de Ugarte Postigo, A.; Gorosabel, J.; Sota, A.; Castro-Tirado, A. J.
GRB Coordinates Network, Circular Service, 8992, 1 (2009)
We have observed the field of GRB 090313 (Mao et al. GCNC 8980) with the 1.5m OSN telescope (Granada, Spain) starting on 22:29 UT (13.4 hours after the burst). Our I-band images show that the optical afterglow reported by Chornock et al. (GCNC 8979) is still bright. Preliminary photometry yields I=17.7+/- 0.3. This would imply that the plateau phase reported by Perley et al. (GCN 8985) is still ongoing, half a day later.
Further observations are encouraged.