GRB170330_222951_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20170331_010534793_000000_55065101     0 star  filter C [ 9158.3s -  9338.3s] expo=180s elev= 3.4deg humid= 49% sunelev=-38.3deg (moon at 127.0deg phase=0.22 elev=-31.0 )
AL_20170331_010845575_000000_55065101     0 star  filter C [ 9349.0s -  9529.0s] expo=180s elev= 3.9deg humid= 52% sunelev=-38.1deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_011156309_000000_55065101    75 stars filter C [ 9539.8s -  9719.8s] expo=180s elev= 4.5deg humid= 53% sunelev=-37.8deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_011535446_000000_55065201    52 stars filter C [ 9758.8s -  9938.8s] expo=180s elev= 5.1deg humid= 54% sunelev=-37.5deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_011846368_000000_55065201    77 stars filter C [ 9949.8s - 10129.8s] expo=180s elev= 5.6deg humid= 54% sunelev=-37.2deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_012157571_000000_55065201    79 stars filter C [10141.0s - 10321.0s] expo=180s elev= 6.1deg humid= 54% sunelev=-36.8deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_012515714_000000_55065301    75 stars filter C [10339.2s - 10519.2s] expo=180s elev= 6.6deg humid= 53% sunelev=-36.5deg (moon at 127.0deg phase=0.22 elev=-32.0 )
AL_20170331_012827495_000000_55065301    80 stars filter C [10530.8s - 10710.8s] expo=180s elev= 7.1deg humid= 51% sunelev=-36.2deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_013138855_000000_55065301    72 stars filter C [10722.3s - 10902.3s] expo=180s elev= 7.6deg humid= 49% sunelev=-35.9deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_013456798_000000_55065401    91 stars filter C [10920.2s - 11100.2s] expo=180s elev= 8.2deg humid= 49% sunelev=-35.5deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_013814517_000000_55065401    85 stars filter C [11117.9s - 11297.9s] expo=180s elev= 8.7deg humid= 49% sunelev=-35.1deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_014125517_000000_55065401    88 stars filter C [11308.9s - 11488.9s] expo=180s elev= 9.2deg humid= 49% sunelev=-34.8deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_014143486_000000_55065501     0 star  filter C [11505.5s - 11685.5s] expo=180s elev= 9.7deg humid= 49% sunelev=-34.4deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_015416595_000000_55065601    80 stars filter C [12080.1s - 12260.1s] expo=180s elev=11.2deg humid= 49% sunelev=-33.3deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_015729367_000000_55065601    90 stars filter C [12272.7s - 12452.7s] expo=180s elev=11.7deg humid= 49% sunelev=-32.9deg (moon at 127.0deg phase=0.22 elev=-33.0 )
AL_20170331_020040429_000000_55065601    85 stars filter C [12463.9s - 12643.9s] expo=180s elev=12.2deg humid= 49% sunelev=-32.5deg (moon at 127.0deg phase=0.23 elev=-33.0 )
AL_20170331_020337289_000000_55065701     0 star  filter C [12663.7s - 12843.7s] expo=180s elev=12.7deg humid= 48% sunelev=-32.1deg (moon at 127.0deg phase=0.23 elev=-33.0 )
AL_20170331_021345056_000000_55065801    94 stars filter C [13248.5s - 13428.5s] expo=180s elev=14.1deg humid= 49% sunelev=-30.8deg (moon at 127.0deg phase=0.23 elev=-33.0 )
AL_20170331_021655606_000000_55065801    91 stars filter C [13439.0s - 13619.0s] expo=180s elev=14.6deg humid= 49% sunelev=-30.4deg (moon at 127.0deg phase=0.23 elev=-33.0 )
AL_20170331_022007215_000000_55065801    84 stars filter C [13630.7s - 13810.7s] expo=180s elev=15.1deg humid= 49% sunelev=-30.0deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_022328653_000000_55065901    94 stars filter C [13832.1s - 14012.1s] expo=180s elev=15.6deg humid= 51% sunelev=-29.5deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_022639416_000000_55065901    87 stars filter C [14022.9s - 14202.9s] expo=180s elev=16.0deg humid= 53% sunelev=-29.1deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_022950838_000000_55065901    93 stars filter C [14214.3s - 14394.3s] expo=180s elev=16.5deg humid= 53% sunelev=-28.7deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_023312197_000000_55066001    91 stars filter C [14415.7s - 14595.7s] expo=180s elev=16.9deg humid= 52% sunelev=-28.2deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_023622780_000000_55066001    82 stars filter C [14606.3s - 14786.3s] expo=180s elev=17.4deg humid= 51% sunelev=-27.7deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_023934264_000000_55066001    98 stars filter C [14797.7s - 14977.7s] expo=180s elev=17.8deg humid= 50% sunelev=-27.3deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_024256623_000000_55066101    79 stars filter C [15000.1s - 15180.1s] expo=180s elev=18.3deg humid= 49% sunelev=-26.8deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_024607405_000000_55066101    95 stars filter C [15190.8s - 15370.8s] expo=180s elev=18.7deg humid= 49% sunelev=-26.3deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_024918765_000000_55066101    88 stars filter C [15382.2s - 15562.2s] expo=180s elev=19.2deg humid= 48% sunelev=-25.9deg (moon at 128.0deg phase=0.23 elev=-33.0 )
AL_20170331_030454008_000000_55066201    98 stars filter C [16317.4s - 16497.4s] expo=180s elev=21.2deg humid= 50% sunelev=-23.5deg (moon at 128.0deg phase=0.23 elev=-32.0 )
AL_20170331_030804741_000000_55066201    82 stars filter C [16508.2s - 16688.2s] expo=180s elev=21.6deg humid= 50% sunelev=-23.0deg (moon at 128.0deg phase=0.23 elev=-32.0 )
AL_20170331_031116397_000000_55066201    96 stars filter C [16699.8s - 16879.8s] expo=180s elev=22.0deg humid= 51% sunelev=-22.5deg (moon at 128.0deg phase=0.23 elev=-32.0 )
AL_20170331_035354174_000000_55066401    93 stars filter C [19257.6s - 19437.6s] expo=180s elev=26.7deg humid= 45% sunelev=-15.6deg (moon at 129.0deg phase=0.23 elev=-30.0 )
AL_20170331_035704737_000000_55066401    93 stars filter C [19448.1s - 19628.1s] expo=180s elev=27.0deg humid= 45% sunelev=-15.0deg (moon at 129.0deg phase=0.23 elev=-29.0 )
AL_20170331_040016378_000000_55066401   102 stars filter C [19639.8s - 19819.8s] expo=180s elev=27.3deg humid= 47% sunelev=-14.5deg (moon at 129.0deg phase=0.23 elev=-29.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457843.4374 2017-03-30T22:29:51.360
Decoded useful notice informations.
RA(J2000.0) : 283.3308 18h53m19s3
DEC(J2000.0) : -13.4312 -13d25m52s31
Error radius : 1.8 arcsec
Error box : x=2996:2997 y=-184:-183 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=21.1310456717 lat=-6.4887228535
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.747
Assuming Rv=3.1: Av=2.478 Ar=1.998 Ai=1.450 Extinction map E(B-V) from Schlegel:

Field of View is about 58 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 170330: TAROT Calern observatory optical observations
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 170330 detected by SWIFT
(trigger 744773) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 2.54h after the GRB trigger.
The elevation of the field increased from
3 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2017-03-30T22:29:51.360

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+9158.3s to t0+9338.3s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+9349.0s to t0+9529.0s : R > 16.2

We co-added a series of exposures:
t0+9349.0s to t0+10519.2s : 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 2.54h 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= 21.1310 lat= -6.4887
and the galactic extinction in R band is 2.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.