GRB180312_001139_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20180312_012300462_000001_12811001     0 star  filter C [ 4186.3s -  4366.3s] expo=180s elev=13.7deg humid= 90% sunelev=-44.1deg (moon at  31.0deg phase=0.34 elev=-16.0 )
AL_20180312_012940647_000003_78540401     0 star  filter C [ 4586.4s -  4766.4s] expo=180s elev=14.9deg humid= 90% sunelev=-43.3deg (moon at  31.0deg phase=0.34 elev=-15.0 )
AL_20180312_013800748_000001_12811201     0 star  filter C [ 5167.4s -  5347.4s] expo=180s elev=16.7deg humid= 89% sunelev=-42.2deg (moon at  31.0deg phase=0.34 elev=-13.0 )
AL_20180312_050432005_000001_12813201     0 star  filter C [17387.2s - 17567.2s] expo=180s elev=48.4deg humid= 82% sunelev=-9.6deg (moon at  32.0deg phase=0.33 elev=+15.0 )
AL_20180312_050742739_000001_12813201     0 star  filter C [17577.9s - 17757.9s] expo=180s elev=48.7deg humid= 81% sunelev=-9.0deg (moon at  32.0deg phase=0.33 elev=+16.0 )
AL_20180312_051053252_000001_12813201     0 star  filter C [17768.4s - 17948.4s] expo=180s elev=49.0deg humid= 81% sunelev=-8.4deg (moon at  32.0deg phase=0.33 elev=+16.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2458189.50809479 2018-03-12T00:11:39.390
Decoded useful notice informations.
RA(J2000.0) : 275.0248 18h20m05s9
DEC(J2000.0) : 7.1924 +07d11m32s64
Error radius : 3.0 arcmin

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=35.8302314966 lat=10.2213380694
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.232
Assuming Rv=3.1: Av=0.770 Ar=0.621 Ai=0.451
extmap.fit: Extinction map E(B-V) from Schlegel:

Field of View is about 61 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 180312: 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 180312 detected by SWIFT
(trigger 813771) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 1.16h after the GRB trigger.
The elevation of the field increased from
13 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2018-03-12T00:11:39.390

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+4186.3s to t0+4366.3s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+4586.4s to t0+4766.4s : R > 16.2

We co-added a series of exposures:
t0+4586.4s to t0+17948.4s : 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 1.16h 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= 35.8302 lat=+10.2213
and the galactic extinction in R band is 0.6 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.
======================================================================