GRB110731_110953_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20110731_203305028_000002_08525901   106 stars filter C [2119276.8s - 2119456.8s] expo=180s elev=16.1deg humid= 89% sunelev=-14.7deg (moon at 135.0deg phase=0.08 elev=-15.0 )
AL_20110731_203416435_000002_08525901     0 star  filter C [2119467.1s - 2119647.1s] expo=180s elev=16.3deg humid= 89% sunelev=-15.1deg (moon at 135.0deg phase=0.08 elev=-15.0 )
Informations from GCN notice:
This is a GRB
Date of GRB : 2455749.8255003472 2011-07-07T07:48:43.229
Date of notice : 2455749.8257754631 2011-07-07T07:49:07.000
Refined position : no
RA(J2000.0) : 22.861000 01h31m26s6
DEC(J2000.0) : 16.758000 +16d45m28s79
Error box : x=184956:185065 y=-31073:-30963 (pixels)

Other pages about TAROT Calern observatory observations

Status of this alert received by TAROT Calern observatory.
Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=6.221653 lat=-10.719329
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.704
Assuming Rv=3.1: Av=2.332 Ar=1.881 Ai=1.365 Extinction map E(B-V) from Schlegel:

Field of View is about 61 arcmin (north is NOT up !)

Bibliography (Last GCNC circulars and status of satellites)

GCN infos of this burst
GCN notice of this burst
Sloan Digital Sky Survey Observations of Gamma Ray Burst Fields
GCN info bursts
Gamma-ray burst real-time sky map
ROTSE last GRB images

Example of a GCNC email for this burst
GRB 110731: TAROT Calern observatory optical observations
Klotz A. (CESR-OMP), Gendre B. (ASDC),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 110731 detected by SWIFT
(trigger 456780) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 2119276.8s after the GRB trigger
(2119253.0s after the notice). The elevation of the field increased from
16 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2011-07-07T07:48:43.199

The first image is trailed with a duration of 180.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+2119276.8s to t0+2119456.8s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+2119467.1s to t0+2119647.1s : R > 16.2

We co-added a series of exposures:
t0+2119467.1s to t0+2119647.1s : R > 17.7
---- YES
We detect a new fading source in the error box given by SWIFT
We detected the candidate couterpart mentioned by XXX et al. (GCNC XXXX)
at the following position (+/- 3 arcsec):

RA(J2000.0) = XXh XXm XX.XXs
DEC(J2000.0) +XXd XX' XX.X"

OT was R~XX.X at 2119276.8s after GRB.

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

N.B. Galactic coordinates are lon=  6.2217 lat=-10.7193
and the galactic extinction in R band is 1.9 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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