Return to Home Page
TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2392 SUBJECT: GRB030913, candidate afterglow observations DATE: 03/09/20 18:09:43 GMT FROM: Arne A. Henden at USNO/USRA <aah@nofs.navy.mil> A. Henden (USRA/USNO) and A. Oksanen (Nyrola Obs.) report on behalf of the AAVSO International High Energy Network: We have examined the early-time R-band images from Nyrola Observatory near the location of the proposed optical transient of Guziy et al. (GCN 2391). A stack of the f5.fit and f5b.fit composite images, giving an effective mid-exposure time of t_0 + 3.5hrs, does not convincingly show any object at the position shown in the Guziy et al. finding chart. A jpeg copy of the stack can be found at http://nyrola.jklsirius.fi/grb/grb030913/f5f5b.jpg Based on nearby USNO-B stars, we can place a limiting magnitude of R=19.5 for any object at this location. Combined with the V=20.9 at t_0 + 4.25day measure of Guziy et al., this would give an unrealistic decay slope for a typical GRB. Either this object is unrelated to the afterglow, or the afterglow increased in brightness after 4hrs. The AAVSO International High Energy network is grateful for a generous grant from the Curry Foundation and to NASA for the financial support for the High Energy Workshops for Amateur Astronomers.
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
