GRB150618_221859_INTEGRAL at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20150618_222020496_000000_00000001     0 star  filter C [   16.3s -    76.3s] expo= 60s elev=45.1deg humid= 76% sunelev=-20.8deg (moon at 129.0deg phase=0.16 elev=-16.0 )
AL_20150618_222105652_000000_00000001    89 stars filter C [   91.5s -   121.5s] expo= 30s elev=45.3deg humid= 76% sunelev=-20.8deg (moon at 129.0deg phase=0.16 elev=-16.0 )
AL_20150618_222146621_000000_00000001    87 stars filter C [  132.5s -   162.5s] expo= 30s elev=45.4deg humid= 76% sunelev=-20.9deg (moon at 129.0deg phase=0.16 elev=-16.0 )
AL_20150618_222227105_000000_00000001    86 stars filter C [  173.0s -   203.0s] expo= 30s elev=45.5deg humid= 76% sunelev=-20.9deg (moon at 129.0deg phase=0.16 elev=-16.0 )
AL_20150618_222307681_000000_00000001    53 stars filter C [  213.5s -   243.5s] expo= 30s elev=45.7deg humid= 76% sunelev=-21.0deg (moon at 129.0deg phase=0.16 elev=-16.0 )
AL_20150618_222348399_000000_00000001    51 stars filter C [  254.3s -   284.3s] expo= 30s elev=45.8deg humid= 77% sunelev=-21.0deg (moon at 129.0deg phase=0.16 elev=-17.0 )
AL_20150618_222358962_000000_00000001     0 star  filter C [  295.0s -   385.0s] expo= 90s elev=46.0deg humid= 77% sunelev=-21.0deg (moon at 129.0deg phase=0.16 elev=-17.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457192.42985 2015-06-18T22:18:59.040
Decoded useful notice informations.
RA(J2000.0) : 306.013335224 20h24m03s2
DEC(J2000.0) : 33.87599452 +33d52m33s58
Error radius : 2.6 arcmin
Error box : x=16:112 y=29:125 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=73.1166139268 lat=-2.08492012392
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 150618: 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 150618 detected by INTEGRAL
(trigger 7041) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 16.3s after the GRB trigger
(14.6s after the notice). The elevation of the field increased from
45 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2015-06-18T22:18:59.040

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+16.3s to t0+76.3s : R > 15.1

The second image is 30.0s exposure in tracking mode:
t0+91.5s to t0+121.5s : R > 16.2

We co-added a series of exposures:
t0+91.5s to t0+385.0s : 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 16.3s 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= 73.1166 lat= -2.0849
and the galactic extinction in R band is 1.3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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