[vsnet-grb-info 7857] GRB 090519: TAROT Calern observatory optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9401
SUBJECT: GRB 090519: TAROT Calern observatory optical observations
DATE:    09/05/19 21:51:16 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz at free.fr>

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

We imaged the field of GRB 090519 detected by SWIFT
(trigger 352648) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 76.0s after the GRB trigger
(6.6s after the notice). The elevation of the field decreased from
21 degrees above horizon and weather conditions
were good.

The date of trigger : t0 = 2009-05-19T21:08:56.5

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 at the XRT position mentionned
by Perri et al. 2009 (GCNC 9400) with a limiting magnitude of:
t0+76.0s to t0+136.0s : R > 16.8

The second image is 30.0s exposure in tracking mode:
t0+142.8s to t0+172.8s : R > 17.5

We co-added a series of exposures:
t0+142.8s to t0+319.6s : R > 18.5

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

N.B. Galactic coordinates are lon=233.3028 lat=+34.5244
and the galactic extinction in R band is 0.1 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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