GRB120617_154656_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20120617_202306296_000002_55423001     0 star  filter C [16385.4s - 16565.4s] expo=180s elev=18.4deg humid= 60% sunelev=-9.7deg (moon at 137.0deg phase=0.11 elev=-21.0 )
AL_20120617_202617234_000002_55423001    30 stars filter R [16576.4s - 16756.4s] expo=180s elev=18.9deg humid= 60% sunelev=-10.1deg (moon at 137.0deg phase=0.11 elev=-21.0 )
AL_20120617_202927788_000002_55423001     7 stars filter V [16766.9s - 16946.9s] expo=180s elev=19.5deg humid= 61% sunelev=-10.4deg (moon at 137.0deg phase=0.11 elev=-21.0 )
AL_20120617_204705247_000002_55423101    95 stars filter C [17824.3s - 18004.3s] expo=180s elev=22.4deg humid= 64% sunelev=-12.5deg (moon at 138.0deg phase=0.11 elev=-23.0 )
AL_20120617_205016674_000002_55423101    68 stars filter R [18015.7s - 18195.7s] expo=180s elev=23.0deg humid= 63% sunelev=-12.9deg (moon at 138.0deg phase=0.11 elev=-23.0 )
AL_20120617_205328095_000002_55423101    30 stars filter V [18207.2s - 18387.2s] expo=180s elev=23.5deg humid= 62% sunelev=-13.2deg (moon at 138.0deg phase=0.11 elev=-23.0 )
AL_20120617_211134186_000002_55423201   101 stars filter C [19293.3s - 19473.3s] expo=180s elev=26.4deg humid= 62% sunelev=-15.2deg (moon at 138.0deg phase=0.11 elev=-24.0 )
AL_20120617_211445435_000002_55423201    90 stars filter R [19484.5s - 19664.5s] expo=180s elev=26.9deg humid= 62% sunelev=-15.5deg (moon at 138.0deg phase=0.11 elev=-24.0 )
AL_20120617_211756826_000002_55423201    38 stars filter V [19675.9s - 19855.9s] expo=180s elev=27.4deg humid= 63% sunelev=-15.8deg (moon at 138.0deg phase=0.11 elev=-24.0 )
AL_20120617_213607010_000002_55423301   104 stars filter C [20766.1s - 20946.1s] expo=180s elev=30.2deg humid= 61% sunelev=-17.5deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_213917982_000002_55423301   104 stars filter R [20957.1s - 21137.1s] expo=180s elev=30.7deg humid= 60% sunelev=-17.7deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_214228233_000002_55423301    42 stars filter V [21147.3s - 21327.3s] expo=180s elev=31.2deg humid= 60% sunelev=-18.0deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_220037323_000002_55423401    96 stars filter C [22236.4s - 22416.4s] expo=180s elev=33.8deg humid= 55% sunelev=-19.4deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_220348510_000002_55423401   100 stars filter R [22427.6s - 22607.6s] expo=180s elev=34.2deg humid= 54% sunelev=-19.6deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_220659230_000002_55423401    42 stars filter V [22618.3s - 22798.3s] expo=180s elev=34.6deg humid= 53% sunelev=-19.8deg (moon at 138.0deg phase=0.11 elev=-25.0 )
AL_20120617_222503131_000002_55423501   112 stars filter C [23702.2s - 23882.2s] expo=180s elev=37.0deg humid= 49% sunelev=-20.9deg (moon at 139.0deg phase=0.10 elev=-25.0 )
AL_20120617_222814348_000002_55423501   104 stars filter R [23893.4s - 24073.4s] expo=180s elev=37.4deg humid= 49% sunelev=-21.1deg (moon at 139.0deg phase=0.10 elev=-25.0 )
AL_20120617_223125495_000002_55423501    36 stars filter V [24084.6s - 24264.6s] expo=180s elev=37.8deg humid= 50% sunelev=-21.2deg (moon at 139.0deg phase=0.10 elev=-25.0 )
AL_20120617_224931694_000002_55423601   113 stars filter C [25170.8s - 25350.8s] expo=180s elev=39.9deg humid= 52% sunelev=-22.0deg (moon at 139.0deg phase=0.10 elev=-25.0 )
AL_20120617_225242679_000002_55423601    95 stars filter R [25361.8s - 25541.8s] expo=180s elev=40.2deg humid= 51% sunelev=-22.1deg (moon at 139.0deg phase=0.10 elev=-25.0 )
AL_20120617_225553429_000002_55423601    40 stars filter V [25552.5s - 25732.5s] expo=180s elev=40.6deg humid= 51% sunelev=-22.2deg (moon at 139.0deg phase=0.10 elev=-24.0 )
AL_20120617_231402580_000002_55423701   135 stars filter C [26641.7s - 26821.7s] expo=180s elev=42.3deg humid= 51% sunelev=-22.7deg (moon at 139.0deg phase=0.10 elev=-24.0 )
AL_20120617_231713611_000002_55423701   115 stars filter R [26832.7s - 27012.7s] expo=180s elev=42.6deg humid= 51% sunelev=-22.7deg (moon at 139.0deg phase=0.10 elev=-24.0 )
AL_20120617_232024821_000002_55423701    32 stars filter V [27023.9s - 27203.9s] expo=180s elev=42.9deg humid= 51% sunelev=-22.8deg (moon at 139.0deg phase=0.10 elev=-23.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2456096.15759 2012-06-17T15:46:55.775
Decoded useful notice informations.
RA(J2000.0) : 282.8109 18h51m14s6
DEC(J2000.0) : -0.0011 -00d00m03s96
Error radius : 2.2 arcsec
Error box : x=36:37 y=36:37 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=32.876066 lat=0.055066
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=19.529
Assuming Rv=3.1: Av=64.739 Ar=52.201 Ai=37.887 Extinction map E(B-V) from Schlegel:

Field of View is about 55 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 120617: 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 120617 detected by SWIFT
(trigger 524542) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 4.55h after the GRB trigger.
The elevation of the field increased from
18 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2012-06-17T15:46:55.775

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+16385.4s to t0+16565.4s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+16576.4s to t0+16756.4s : R > 16.2

We co-added a series of exposures:
t0+16576.4s to t0+19473.3s : 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 4.55h 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= 32.8761 lat= +0.0551
and the galactic extinction in R band is 52.2 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.