GRB171212_115722_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20171212_165649270_000000_99381501     0 star  filter C [17782.5s - 17962.5s] expo=180s elev=44.0deg humid= 68% sunelev=-10.4deg (moon at  96.0deg phase=0.34 elev=-38.0 )
AL_20171212_165959582_000000_99381501     0 star  filter C [17972.8s - 18152.8s] expo=180s elev=43.4deg humid= 67% sunelev=-10.9deg (moon at  96.0deg phase=0.34 elev=-39.0 )
AL_20171212_170309637_000000_99381501    32 stars filter C [18162.9s - 18342.9s] expo=180s elev=42.8deg humid= 64% sunelev=-11.5deg (moon at  96.0deg phase=0.34 elev=-39.0 )
AL_20171212_172126135_000000_99381601    43 stars filter C [19259.4s - 19439.4s] expo=180s elev=39.6deg humid= 63% sunelev=-14.6deg (moon at  95.0deg phase=0.34 elev=-41.0 )
AL_20171212_172435982_000000_99381601    60 stars filter C [19449.2s - 19629.2s] expo=180s elev=39.0deg humid= 62% sunelev=-15.1deg (moon at  95.0deg phase=0.34 elev=-42.0 )
AL_20171212_172746497_000000_99381601    60 stars filter C [19639.7s - 19819.7s] expo=180s elev=38.5deg humid= 62% sunelev=-15.7deg (moon at  95.0deg phase=0.34 elev=-42.0 )
AL_20171212_174553829_000000_99381701    50 stars filter C [20727.0s - 20907.0s] expo=180s elev=35.2deg humid= 64% sunelev=-18.8deg (moon at  95.0deg phase=0.34 elev=-44.0 )
AL_20171212_174903626_000000_99381701    56 stars filter C [20916.8s - 21096.8s] expo=180s elev=34.6deg humid= 63% sunelev=-19.4deg (moon at  95.0deg phase=0.34 elev=-44.0 )
AL_20171212_175213735_000000_99381701    52 stars filter C [21106.9s - 21286.9s] expo=180s elev=34.1deg humid= 62% sunelev=-19.9deg (moon at  95.0deg phase=0.34 elev=-45.0 )
AL_20171212_181024587_000000_99381801    53 stars filter C [22197.8s - 22377.8s] expo=180s elev=30.8deg humid= 62% sunelev=-23.1deg (moon at  95.0deg phase=0.34 elev=-46.0 )
AL_20171212_181334790_000000_99381801    62 stars filter C [22388.1s - 22568.1s] expo=180s elev=30.2deg humid= 61% sunelev=-23.7deg (moon at  95.0deg phase=0.34 elev=-47.0 )
AL_20171212_181645316_000000_99381801    50 stars filter C [22578.6s - 22758.6s] expo=180s elev=29.6deg humid= 62% sunelev=-24.3deg (moon at  95.0deg phase=0.34 elev=-47.0 )
AL_20171212_183447343_000000_99381901    54 stars filter C [23660.6s - 23840.6s] expo=180s elev=26.4deg humid= 64% sunelev=-27.5deg (moon at  95.0deg phase=0.34 elev=-48.0 )
AL_20171212_183758078_000000_99381901    61 stars filter C [23851.3s - 24031.3s] expo=180s elev=25.8deg humid= 63% sunelev=-28.1deg (moon at  95.0deg phase=0.34 elev=-48.0 )
AL_20171212_184108140_000000_99381901    51 stars filter C [24041.3s - 24221.3s] expo=180s elev=25.2deg humid= 62% sunelev=-28.6deg (moon at  95.0deg phase=0.34 elev=-49.0 )
AL_20171212_185918409_000000_99382001    57 stars filter C [25131.6s - 25311.6s] expo=180s elev=22.0deg humid= 65% sunelev=-31.9deg (moon at  95.0deg phase=0.34 elev=-49.0 )
AL_20171212_190228409_000000_99382001    56 stars filter C [25321.6s - 25501.6s] expo=180s elev=21.4deg humid= 65% sunelev=-32.5deg (moon at  95.0deg phase=0.34 elev=-50.0 )
AL_20171212_190538451_000000_99382001    50 stars filter C [25511.7s - 25691.7s] expo=180s elev=20.8deg humid= 64% sunelev=-33.0deg (moon at  95.0deg phase=0.34 elev=-50.0 )
AL_20171212_192349226_000000_99382101    53 stars filter C [26602.4s - 26782.4s] expo=180s elev=17.6deg humid= 65% sunelev=-36.3deg (moon at  94.0deg phase=0.34 elev=-50.0 )
AL_20171212_192659483_000000_99382101    57 stars filter C [26792.7s - 26972.7s] expo=180s elev=17.0deg humid= 65% sunelev=-36.9deg (moon at  94.0deg phase=0.34 elev=-50.0 )
AL_20171212_193009295_000000_99382101    52 stars filter C [26982.5s - 27162.5s] expo=180s elev=16.5deg humid= 64% sunelev=-37.5deg (moon at  94.0deg phase=0.34 elev=-50.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2458099.99816759 2017-12-12T11:57:21.680
Decoded useful notice informations.
RA(J2000.0) : 293.9004 19h35m36s0
DEC(J2000.0) : 20.5684 +20d34m06s23
Error radius : 3.0 arcmin

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=56.1624257544 lat=0.0359749565722
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=7.845
Assuming Rv=3.1: Av=26.005 Ar=20.969 Ai=15.219 Extinction map E(B-V) from Schlegel:

Field of View is about 55 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 171212: 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 171212 detected by SWIFT
(trigger 796778) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 4.94h after the GRB trigger.
The elevation of the field decreased from
43 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2017-12-12T11:57:21.680

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+17782.5s to t0+17962.5s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+17972.8s to t0+18152.8s : R > 16.2

We co-added a series of exposures:
t0+17972.8s to t0+20907.0s : 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 4.94h 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= 56.1624 lat= +0.0360
and the galactic extinction in R band is 21.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.