GRB121123_100241_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20121123_170458734_000002_65989501     0 star  filter C [25152.7s - 25332.7s] expo=180s elev=32.0deg humid= 87% sunelev=-11.2deg (moon at  61.0deg phase=0.70 elev=+38.0 )
AL_20121123_170809754_000002_65989501     0 star  filter R [25343.6s - 25523.6s] expo=180s elev=31.8deg humid= 87% sunelev=-11.7deg (moon at  61.0deg phase=0.70 elev=+38.0 )
AL_20121123_171121598_000002_65989501     0 star  filter V [25535.5s - 25715.5s] expo=180s elev=31.6deg humid= 86% sunelev=-12.3deg (moon at  61.0deg phase=0.70 elev=+39.0 )
AL_20121123_172921919_000002_65989601     0 star  filter C [26615.9s - 26795.9s] expo=180s elev=30.2deg humid= 81% sunelev=-15.4deg (moon at  61.0deg phase=0.70 elev=+41.0 )
AL_20121123_173232904_000002_65989601     0 star  filter R [26806.8s - 26986.8s] expo=180s elev=29.9deg humid= 80% sunelev=-16.0deg (moon at  61.0deg phase=0.70 elev=+42.0 )
AL_20121123_173543888_000002_65989601     0 star  filter V [26997.8s - 27177.8s] expo=180s elev=29.6deg humid= 80% sunelev=-16.6deg (moon at  61.0deg phase=0.70 elev=+42.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2456254.91853 2012-11-23T10:02:40.991
Decoded useful notice informations.
RA(J2000.0) : 307.3179 20h29m16s2
DEC(J2000.0) : -11.8598 -11d51m35s28
Error radius : 0.4 arcsec

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=33.071519 lat=-27.061065
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.117
Assuming Rv=3.1: Av=0.389 Ar=0.313 Ai=0.227
extmap.fit: Extinction map E(B-V) from Schlegel:

Field of View is about 74 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
GRBlog
ROTSE last GRB images

Example of a GCNC email for this burst

gcncirc@capella.gsfc.nasa.gov
GRB 121123: TAROT Calern observatory optical observations
----------------------------------------------------------------------
Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 121123 detected by SWIFT
(trigger 539358) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 6.99h after the GRB trigger.
The elevation of the field decreased from
32 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2012-11-23T10:02:40.991

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+25152.7s to t0+25332.7s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+25343.6s to t0+25523.6s : R > 16.2

We co-added a series of exposures:
t0+25343.6s to t0+27177.8s : 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 6.99h 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= 33.0715 lat=-27.0611
and the galactic extinction in R band is 0.3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.
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