TITLE:   GCN CIRCULAR
NUMBER:  7822
SUBJECT: GRB 080603A: TLS Afterglow Observation
DATE:    08/06/05 15:22:40 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, U. Laux and S. Ertel (TLS Tautenburg) report:

We observed the field of the INTEGRAL GRB 080603A (Paizis et al., GCN 
7790) with the TLS 1.34m Schmidt telescope in mediocre observing 
conditions (low airmass but high humidity and moderate transparency). We 
obtained a total of 6 x 600 sec images at mid-time June 5.023368. The 
afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) is faintly 
visible in each image. We stacked all six images. Assuming the USNOB1.0 
star with ID 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 to have 
R1 = 16.74 mag, we measure for the afterglow:

dt	Rc	dRc

1.55241	21.39	0.03 (statistical only)

We note the presence of a fainter source several arcseconds east of the OT 
which may slightly influence the photometry.

In comparison to the magnitude measured by Perley et al. (GCN 7791), this 
implies a slow decay of alpha ~ 0.5. Further observations are warranted.

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