GRB120913_201822_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20120914_020636523_000002_61435601     0 star  filter C [20709.4s - 20889.4s] expo=180s elev= 2.6deg humid= 60% sunelev=-31.3deg (moon at  19.0deg phase=0.14 elev=-12.0 )
AL_20120914_020947293_000002_61435601     0 star  filter R [20900.1s - 21080.1s] expo=180s elev= 3.1deg humid= 61% sunelev=-30.8deg (moon at  19.0deg phase=0.14 elev=-11.0 )
AL_20120914_021258527_000002_61435601     0 star  filter V [21091.3s - 21271.3s] expo=180s elev= 3.5deg humid= 60% sunelev=-30.4deg (moon at  19.0deg phase=0.14 elev=-11.0 )
AL_20120914_023103505_000002_61435701     1 star  filter C [22176.3s - 22356.3s] expo=180s elev= 6.2deg humid= 59% sunelev=-27.9deg (moon at  19.0deg phase=0.14 elev= -8.0 )
AL_20120914_023414724_000002_61435701     1 star  filter R [22367.5s - 22547.5s] expo=180s elev= 6.6deg humid= 57% sunelev=-27.4deg (moon at  19.0deg phase=0.14 elev= -7.0 )
AL_20120914_023725020_000002_61435701     1 star  filter V [22557.8s - 22737.8s] expo=180s elev= 7.1deg humid= 56% sunelev=-26.9deg (moon at  19.0deg phase=0.14 elev= -7.0 )
AL_20120914_025537512_000002_61435801     1 star  filter C [23650.4s - 23830.4s] expo=180s elev=10.0deg humid= 56% sunelev=-24.2deg (moon at  19.0deg phase=0.14 elev= -4.0 )
AL_20120914_025848751_000002_61435801     1 star  filter R [23841.6s - 24021.6s] expo=180s elev=10.5deg humid= 56% sunelev=-23.7deg (moon at  19.0deg phase=0.14 elev= -3.0 )
AL_20120914_030159237_000002_61435801     2 stars filter V [24032.1s - 24212.1s] expo=180s elev=11.0deg humid= 57% sunelev=-23.2deg (moon at  19.0deg phase=0.14 elev= -3.0 )
AL_20120914_032001104_000002_61435901     2 stars filter C [25113.9s - 25293.9s] expo=180s elev=13.9deg humid= 60% sunelev=-20.3deg (moon at  19.0deg phase=0.14 elev= +0.0 )
AL_20120914_032312291_000002_61435901     1 star  filter R [25305.1s - 25485.1s] expo=180s elev=14.4deg humid= 60% sunelev=-19.8deg (moon at  19.0deg phase=0.14 elev= +0.0 )
AL_20120914_032622806_000002_61435901     3 stars filter V [25495.6s - 25675.6s] expo=180s elev=15.0deg humid= 60% sunelev=-19.3deg (moon at  19.0deg phase=0.14 elev= +0.0 )
AL_20120914_034440111_000002_61436001     3 stars filter C [26592.9s - 26772.9s] expo=180s elev=18.0deg humid= 63% sunelev=-16.3deg (moon at  19.0deg phase=0.14 elev= +3.0 )
AL_20120914_034751282_000002_61436001     1 star  filter R [26784.1s - 26964.1s] expo=180s elev=18.6deg humid= 64% sunelev=-15.7deg (moon at  19.0deg phase=0.14 elev= +4.0 )
AL_20120914_035102471_000002_61436001     3 stars filter V [26975.3s - 27155.3s] expo=180s elev=19.1deg humid= 64% sunelev=-15.2deg (moon at  19.0deg phase=0.14 elev= +5.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2456184.34609 2012-09-13T20:18:22.176
Decoded useful notice informations.
RA(J2000.0) : 146.4368 09h45m44s8
DEC(J2000.0) : 26.9767 +26d58m36s11
Error radius : 3.0 arcmin

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=202.094129 lat=48.902579
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.017
Assuming Rv=3.1: Av=0.056 Ar=0.046 Ai=0.033 Extinction map E(B-V) from Schlegel:

Field of View is about 111 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 120913: 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 120913 detected by SWIFT
(trigger 533568) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 5.75h after the GRB trigger.
The elevation of the field increased from
2 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2012-09-13T20:18:22.176

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+20709.4s to t0+20889.4s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+20900.1s to t0+21080.1s : R > 16.2

We co-added a series of exposures:
t0+20900.1s to t0+23830.4s : 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 5.75h 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=202.0941 lat=+48.9026
and the galactic extinction in R band is 0.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.