GRB150621_205817_INTEGRAL at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20150621_205838133_000000_00000001     0 star  filter C [   18.8s -    78.8s] expo= 60s elev=33.0deg humid= 84% sunelev=-14.0deg (moon at 131.0deg phase=0.34 elev=+12.0 )
AL_20150621_211152068_000003_46612701    39 stars filter C [  719.7s -   809.7s] expo= 90s elev=35.0deg humid= 80% sunelev=-15.3deg (moon at 131.0deg phase=0.34 elev=+10.0 )
AL_20150621_211333302_000003_46612701    36 stars filter C [  821.0s -   911.0s] expo= 90s elev=35.3deg humid= 82% sunelev=-15.4deg (moon at 131.0deg phase=0.34 elev=+10.0 )
AL_20150621_211513786_000003_46612701    40 stars filter C [  921.5s -  1011.5s] expo= 90s elev=35.6deg humid= 82% sunelev=-15.6deg (moon at 131.0deg phase=0.34 elev=+10.0 )
AL_20150621_211714927_000003_46612801    47 stars filter C [ 1042.6s -  1132.6s] expo= 90s elev=36.0deg humid= 83% sunelev=-15.8deg (moon at 131.0deg phase=0.34 elev= +9.0 )
AL_20150621_211856430_000003_46612801    47 stars filter C [ 1144.1s -  1234.1s] expo= 90s elev=36.3deg humid= 84% sunelev=-15.9deg (moon at 131.0deg phase=0.34 elev= +9.0 )
AL_20150621_212037649_000003_46612801    51 stars filter C [ 1245.3s -  1335.3s] expo= 90s elev=36.6deg humid= 84% sunelev=-16.1deg (moon at 131.0deg phase=0.34 elev= +9.0 )
AL_20150621_235522951_000003_46614501    73 stars filter C [10440.7s - 10620.7s] expo=180s elev=64.2deg humid= 84% sunelev=-22.7deg (moon at 131.0deg phase=0.35 elev=-16.0 )
AL_20150621_235834138_000003_46614501    60 stars filter C [10631.9s - 10811.9s] expo=180s elev=64.7deg humid= 83% sunelev=-22.6deg (moon at 131.0deg phase=0.35 elev=-17.0 )
AL_20150622_000144451_000003_46614501    57 stars filter R [10822.2s - 11002.2s] expo=180s elev=65.3deg humid= 83% sunelev=-22.6deg (moon at 131.0deg phase=0.35 elev=-17.0 )
AL_20150622_000506544_000003_46614601    67 stars filter C [11024.3s - 11204.3s] expo=180s elev=65.9deg humid= 82% sunelev=-22.5deg (moon at 131.0deg phase=0.35 elev=-18.0 )
AL_20150622_000817529_000003_46614601    66 stars filter C [11215.3s - 11395.3s] expo=180s elev=66.4deg humid= 81% sunelev=-22.4deg (moon at 131.0deg phase=0.35 elev=-18.0 )
AL_20150622_001128326_000003_46614601    60 stars filter R [11406.0s - 11586.0s] expo=180s elev=67.0deg humid= 80% sunelev=-22.3deg (moon at 131.0deg phase=0.35 elev=-19.0 )
AL_20150622_001451617_000003_46614701    61 stars filter C [11609.3s - 11789.3s] expo=180s elev=67.6deg humid= 80% sunelev=-22.2deg (moon at 131.0deg phase=0.35 elev=-19.0 )
AL_20150622_001802648_000003_46614701    69 stars filter C [11800.3s - 11980.3s] expo=180s elev=68.1deg humid= 80% sunelev=-22.1deg (moon at 131.0deg phase=0.35 elev=-20.0 )
AL_20150622_002113305_000003_46614701    59 stars filter R [11991.0s - 12171.0s] expo=180s elev=68.7deg humid= 80% sunelev=-22.0deg (moon at 131.0deg phase=0.35 elev=-20.0 )
AL_20150622_002435261_000003_46614801    71 stars filter C [12192.9s - 12372.9s] expo=180s elev=69.2deg humid= 81% sunelev=-21.9deg (moon at 131.0deg phase=0.35 elev=-21.0 )
AL_20150622_002746746_000003_46614801    70 stars filter C [12384.3s - 12564.3s] expo=180s elev=69.8deg humid= 81% sunelev=-21.8deg (moon at 131.0deg phase=0.35 elev=-21.0 )
AL_20150622_002859715_000003_46614801     0 star  filter R [12575.1s - 12755.1s] expo=180s elev=70.3deg humid= 81% sunelev=-21.7deg (moon at 131.0deg phase=0.35 elev=-22.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457195.37381 2015-06-21T20:58:17.184
Decoded useful notice informations.
RA(J2000.0) : 306.002561365 20h24m00s6
DEC(J2000.0) : 33.8751811609 +33d52m30s65
Error radius : 2.6 arcmin
Error box : x=30:125 y=32:127 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=73.1150771743 lat=-2.09614701779
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.500
Assuming Rv=3.1: Av=1.657 Ar=1.336 Ai=0.970 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 150621: 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 150621 detected by INTEGRAL
(trigger 7094) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 18.8s after the GRB trigger
(13.6s after the notice). The elevation of the field increased from
32 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2015-06-21T20:58:17.184

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+18.8s to t0+78.8s : R > 15.1

The second image is 90.0s exposure in tracking mode:
t0+719.7s to t0+809.7s : R > 16.2

We co-added a series of exposures:
t0+719.7s to t0+1335.3s : 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 18.8s 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= 73.1151 lat= -2.0961
and the galactic extinction in R band is 1.3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.