TITLE:   GCN CIRCULAR
NUMBER:  7417
SUBJECT: GRB 080315: TAROT Calern observatory optical observations
DATE:    08/03/15 03:08:37 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 080315 detected by SWIFT
(trigger 306323) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 85.0s after the GRB trigger
(9.4s after the notice). The elevation of the field decreased from
from 45 degrees above horizon and weather conditions
were excellents.

The date of trigger : t0 = 2008-03-15T02:25:01.3

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+85.0s to t0+145.0s : R > 16.8

The second image is 30.0s exposure in tracking mode:
t0+152.1s to t0+182.1s : R > 18.3

We co-added a series of exposures:
t0+152.1s to t0+436.0s : R > 19.7

These images are unfiltered.

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=177.6257 lat=+56.0163
and the galactic extinction in R band less than 0.1 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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