TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3535
SUBJECT: GRB 050607: PROMPT VRcIc Observations
DATE:    05/06/08 00:25:17 GMT
FROM:    Melissa Nysewander at UNC,Chapel Hill  <mnysewan@astro.unc.edu>

M. Nysewander, D. Reichart, J. A. Crain, A. Foster, M. Bayliss report on
behalf of the UNC team of the FUN GRB Collaboration:

We observed the BAT localization of GRB 050607 (Retter et al., GCN 3525)
with PROMPT beginning 13m 30s after the burst.

We do not detect a source within the refined XRT localization (Pagani et
al., GCN 3528) nor the source identified by Rhoads (GCN 3527).

3-sigma limiting magnitudes are based on 10 USNO-B1.0 stars for Rc and Ic
observations and 10 NOMAD stars for V observations.  Initial limiting
magnitudes are poor due to a camera cooling error:

Mean Time	Integration 	Filter	Limiting	Telescope
Since GRB	Time			Magnitude

14m 08s		1 x 77.5s	Ic	17.5		PROMPT-5
17m 43s		2 x 77.5s	V	18.4		PROMPT-5
21m 16m		1 x 77.5s	Rc	19.7		PROMPT-5
24m 06s		1 x 77.5s	Ic	19.2		PROMPT-5
26m 21s		2 x 77.5s	V	19.5		PROMPT-5
29m 51s		3 x 76.25s	Rc	20.5		PROMPT-5
36m 17s		4 x 76.25s	Ic	20.2		PROMPT-5
41m 48s		3 x 76.25s	V	19.4		PROMPT-5
47m 17s		2 x 76.25s	Rc	20.3		PROMPT-5
51m 25s		1 x 76.25s	Ic	19.4		PROMPT-5

Stacking all images yields 3-sigma limiting magnitudes of Ic > 20.5, Rc >
21.2, and V > 19.8.

PROMPT is still being built and commissioned.