GRB150620_185449_INTEGRAL at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20150621_013111052_000003_46524601     0 star  filter C [23596.7s - 23776.7s] expo=180s elev=78.4deg humid= 75% sunelev=-17.8deg (moon at 133.0deg phase=0.29 elev=-31.0 )
AL_20150621_013422255_000003_46524601     0 star  filter R [23787.9s - 23967.9s] expo=180s elev=78.7deg humid= 75% sunelev=-17.5deg (moon at 133.0deg phase=0.29 elev=-31.0 )
AL_20150621_013733708_000003_46524601     0 star  filter V [23979.4s - 24159.4s] expo=180s elev=79.0deg humid= 76% sunelev=-17.3deg (moon at 133.0deg phase=0.29 elev=-32.0 )
AL_20150621_020016993_000003_46524701     0 star  filter C [25342.7s - 25522.7s] expo=180s elev=80.1deg humid= 75% sunelev=-15.1deg (moon at 133.0deg phase=0.30 elev=-33.0 )
AL_20150621_020328197_000003_46524701     0 star  filter R [25533.9s - 25713.9s] expo=180s elev=80.1deg humid= 75% sunelev=-14.8deg (moon at 133.0deg phase=0.30 elev=-34.0 )
AL_20150621_020639868_000003_46524701     0 star  filter V [25725.6s - 25905.6s] expo=180s elev=80.1deg humid= 75% sunelev=-14.5deg (moon at 133.0deg phase=0.30 elev=-34.0 )
AL_20150621_022006755_000003_46524801     0 star  filter C [26532.4s - 26712.4s] expo=180s elev=79.6deg humid= 74% sunelev=-13.0deg (moon at 133.0deg phase=0.30 elev=-34.0 )
AL_20150621_022317708_000003_46524801     0 star  filter R [26723.4s - 26903.4s] expo=180s elev=79.4deg humid= 74% sunelev=-12.7deg (moon at 133.0deg phase=0.30 elev=-35.0 )
AL_20150621_022628911_000003_46524801     0 star  filter V [26914.6s - 27094.6s] expo=180s elev=79.1deg humid= 73% sunelev=-12.3deg (moon at 133.0deg phase=0.30 elev=-35.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457194.28807 2015-06-20T18:54:49.248
Decoded useful notice informations.
RA(J2000.0) : 306.032803028 20h24m07s8
DEC(J2000.0) : 33.8357541463 +33d50m08s71
Error radius : 3.0 arcmin

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=73.1011698291 lat=-2.12109062129
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.512
Assuming Rv=3.1: Av=1.696 Ar=1.367 Ai=0.992 Extinction map E(B-V) from Schlegel:

Field of View is about 56 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 150620: TAROT Calern observatory optical observations
Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 150620 detected by INTEGRAL
(trigger 7072) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 6.55h after the GRB trigger.
The elevation of the field increased from
78 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2015-06-20T18:54:49.248

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+23596.7s to t0+23776.7s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+23787.9s to t0+23967.9s : R > 16.2

We co-added a series of exposures:
t0+23787.9s to t0+26712.4s : R > 17.7
---- YES
We detect a new fading source in the error box given by INTEGRAL
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 6.55h 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= 73.1012 lat= -2.1211
and the galactic extinction in R band is 1.4 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.