GRB180407_040518_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20180407_040653787_000000_00000001     0 star  filter C [   30.5s -    90.5s] expo= 60s elev=53.2deg humid= 50% sunelev=-10.8deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_040737553_000000_00000001     0 star  filter C [  104.2s -   134.2s] expo= 30s elev=53.1deg humid= 62% sunelev=-10.6deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_040817600_000000_00000001     0 star  filter C [  144.3s -   174.3s] expo= 30s elev=53.0deg humid= 51% sunelev=-10.5deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_040857412_000000_00000001     0 star  filter C [  184.1s -   214.1s] expo= 30s elev=52.9deg humid= 51% sunelev=-10.4deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_040937225_000000_00000001     1 star  filter C [  223.9s -   253.9s] expo= 30s elev=52.8deg humid= 51% sunelev=-10.3deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041017022_000000_00000001     2 stars filter C [  263.7s -   293.7s] expo= 30s elev=52.6deg humid= 50% sunelev=-10.1deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041157100_000000_00000001     3 stars filter C [  303.8s -   393.8s] expo= 90s elev=52.5deg humid= 50% sunelev=-10.0deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041337161_000000_00000001     4 stars filter C [  403.9s -   493.9s] expo= 90s elev=52.2deg humid= 51% sunelev=-9.8deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041517677_000000_00000001     3 stars filter C [  504.4s -   594.4s] expo= 90s elev=51.9deg humid= 62% sunelev=-9.5deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041657724_000000_00000001     0 star  filter C [  604.4s -   694.4s] expo= 90s elev=51.7deg humid= 62% sunelev=-9.2deg (moon at  90.0deg phase=0.57 elev=+24.0 )
AL_20180407_041838240_000000_00000001     0 star  filter C [  704.9s -   794.9s] expo= 90s elev=51.4deg humid= 51% sunelev=-8.9deg (moon at  90.0deg phase=0.57 elev=+24.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2458215.67035023 2018-04-07T04:05:18.260
Decoded useful notice informations.
RA(J2000.0) : 209.9378 13h59m45s0
DEC(J2000.0) : 48.6535 +48d39m12s60
Error radius : 3.0 arcmin

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=95.8971268542 lat=64.7331750853
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.021
Assuming Rv=3.1: Av=0.069 Ar=0.056 Ai=0.040
extmap.fit: Extinction map E(B-V) from Schlegel:

Field of View is about 179 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
GRBlog
ROTSE last GRB images

Example of a GCNC email for this burst

gcncirc@capella.gsfc.nasa.gov
GRB 180407: TAROT Calern observatory optical observations
----------------------------------------------------------------------
Klotz A., Noysena.K., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Eymar, L. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 180407 detected by SWIFT
(trigger 823014) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 30.5s after the GRB trigger
(13.7s after the notice). The elevation of the field decreased from
53 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2018-04-07T04:05:18.260

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+30.5s to t0+90.5s : R > 15.1

The second image is 30.0s exposure in tracking mode:
t0+104.2s to t0+134.2s : R > 16.2

We co-added a series of exposures:
t0+104.2s to t0+393.8s : 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 30.5s 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= 95.8971 lat=+64.7332
and the galactic extinction in R band is 0.1 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.
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