R.A. 04h 17m 09s.4, Decl. +18o11' 57."9 (J2000.0) |
GCN Circular #3900: GRB 050827: Optical Limit |
J. P. Halpern (Columbia U.) reports on behalf of the MDM Observatory GRB follow-up team: "I observed the error box of GRB 050827 (Swift trigger #152325, GCN #3893) in the R band with the MDM 1.3m telescope for 50 minutes starting on Aug. 28 09:32 UT, or 14.6 hours after the burst. There is no optical object to a limiting magnitude R=23.5 within 16", or twice the error circle radius, of the XRT candidate afterglow reported by Capalbi et al. (GCN #3899). Even after correcting this limit for Galactic absorption A(R)=1.47 mag at its location (Schlegel et al. 1998), it would be unusual for a persistent X-ray source of flux 1.0E-12 erg cm^-2 s^-1 to have no optical counterpart. So this supports the identification of the X-ray source as the GRB afterglow." |
Jules Halpern jules@astro.columbia.edu |
Nestor Mirabal mirabal@umich.edu |
Back to the main MDM GRB page |
Last Modified: August 30, 2005 | jules@astro.columbia.edu |