GRB170531_220209_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20170531_221009897_000000_00000001     0 star  filter C [  456.5s -   486.5s] expo= 30s elev= 9.9deg humid= 61% sunelev=-21.8deg (moon at 133.0deg phase=0.46 elev=+18.0 )
AL_20170531_222314665_000003_72204001     9 stars filter C [ 1170.4s -  1260.4s] expo= 90s elev=11.7deg humid= 60% sunelev=-22.5deg (moon at 133.0deg phase=0.46 elev=+16.0 )
AL_20170531_222456352_000003_72204001    12 stars filter C [ 1272.1s -  1362.1s] expo= 90s elev=12.0deg humid= 59% sunelev=-22.5deg (moon at 133.0deg phase=0.46 elev=+15.0 )
AL_20170531_222637133_000003_72204001    19 stars filter C [ 1372.8s -  1462.8s] expo= 90s elev=12.2deg humid= 59% sunelev=-22.6deg (moon at 133.0deg phase=0.46 elev=+15.0 )
AL_20170531_222823680_000003_72204101    29 stars filter C [ 1479.4s -  1569.4s] expo= 90s elev=12.5deg humid= 59% sunelev=-22.7deg (moon at 133.0deg phase=0.46 elev=+15.0 )
AL_20170531_223005140_000003_72204101    34 stars filter C [ 1580.8s -  1670.8s] expo= 90s elev=12.7deg humid= 59% sunelev=-22.8deg (moon at 133.0deg phase=0.46 elev=+14.0 )
AL_20170531_223146593_000003_72204101    35 stars filter C [ 1682.3s -  1772.3s] expo= 90s elev=13.0deg humid= 59% sunelev=-22.9deg (moon at 133.0deg phase=0.46 elev=+14.0 )
AL_20170531_223333609_000003_72204201    27 stars filter C [ 1789.3s -  1879.3s] expo= 90s elev=13.2deg humid= 59% sunelev=-23.0deg (moon at 133.0deg phase=0.46 elev=+14.0 )
AL_20170531_223514562_000003_72204201    38 stars filter C [ 1890.3s -  1980.3s] expo= 90s elev=13.4deg humid= 59% sunelev=-23.0deg (moon at 133.0deg phase=0.46 elev=+13.0 )
AL_20170531_223656515_000003_72204201    38 stars filter C [ 1992.2s -  2082.2s] expo= 90s elev=13.7deg humid= 58% sunelev=-23.1deg (moon at 133.0deg phase=0.46 elev=+13.0 )
AL_20170531_224120093_000003_72204301    38 stars filter C [ 2165.8s -  2345.8s] expo=180s elev=14.2deg humid= 58% sunelev=-23.2deg (moon at 133.0deg phase=0.46 elev=+12.0 )
AL_20170531_224431077_000003_72204301    43 stars filter C [ 2356.7s -  2536.7s] expo=180s elev=14.6deg humid= 57% sunelev=-23.3deg (moon at 133.0deg phase=0.46 elev=+12.0 )
AL_20170531_224742265_000003_72204301    69 stars filter C [ 2548.0s -  2728.0s] expo=180s elev=15.1deg humid= 56% sunelev=-23.5deg (moon at 133.0deg phase=0.46 elev=+11.0 )
AL_20170531_225104851_000003_72204401    80 stars filter C [ 2750.5s -  2930.5s] expo=180s elev=15.5deg humid= 57% sunelev=-23.6deg (moon at 133.0deg phase=0.46 elev=+11.0 )
AL_20170531_225415804_000003_72204401    57 stars filter C [ 2941.5s -  3121.5s] expo=180s elev=15.9deg humid= 58% sunelev=-23.7deg (moon at 133.0deg phase=0.46 elev=+10.0 )
AL_20170531_225726554_000003_72204401    83 stars filter C [ 3132.3s -  3312.3s] expo=180s elev=16.4deg humid= 58% sunelev=-23.8deg (moon at 132.0deg phase=0.46 elev=+10.0 )
AL_20170531_230048908_000003_72204501    66 stars filter C [ 3334.6s -  3514.6s] expo=180s elev=16.8deg humid= 58% sunelev=-23.8deg (moon at 132.0deg phase=0.46 elev= +9.0 )
AL_20170531_230359877_000003_72204501    83 stars filter C [ 3525.6s -  3705.6s] expo=180s elev=17.2deg humid= 58% sunelev=-23.9deg (moon at 132.0deg phase=0.46 elev= +8.0 )
AL_20170531_230712064_000003_72204501    65 stars filter C [ 3717.7s -  3897.7s] expo=180s elev=17.6deg humid= 59% sunelev=-24.0deg (moon at 132.0deg phase=0.46 elev= +8.0 )
AL_20170531_231032311_000000_66771701    45 stars filter C [ 3918.0s -  4098.0s] expo=180s elev=18.0deg humid= 59% sunelev=-24.1deg (moon at 132.0deg phase=0.46 elev= +7.0 )
AL_20170531_231343327_000000_66771701    17 stars filter C [ 4109.0s -  4289.0s] expo=180s elev=18.4deg humid= 58% sunelev=-24.1deg (moon at 132.0deg phase=0.46 elev= +7.0 )
AL_20170531_231654530_000000_66771701     5 stars filter C [ 4300.2s -  4480.2s] expo=180s elev=18.8deg humid= 58% sunelev=-24.1deg (moon at 132.0deg phase=0.46 elev= +6.0 )
AL_20170531_232016133_000000_66771801    26 stars filter C [ 4501.8s -  4681.8s] expo=180s elev=19.2deg humid= 57% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +6.0 )
AL_20170531_232327789_000000_66771801    47 stars filter C [ 4693.5s -  4873.5s] expo=180s elev=19.6deg humid= 56% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +5.0 )
AL_20170531_232638789_000000_66771801    23 stars filter C [ 4884.5s -  5064.5s] expo=180s elev=20.0deg humid= 56% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +4.0 )
AL_20170531_233001121_000000_66771901     0 star  filter C [ 5086.8s -  5266.8s] expo=180s elev=20.4deg humid= 56% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +4.0 )
AL_20170531_233313043_000000_66771901     0 star  filter C [ 5278.8s -  5458.8s] expo=180s elev=20.7deg humid= 55% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +3.0 )
AL_20170531_233623808_000000_66771901     0 star  filter C [ 5469.5s -  5649.5s] expo=180s elev=21.1deg humid= 55% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +3.0 )
AL_20170531_233945246_000000_66772001     5 stars filter C [ 5670.9s -  5850.9s] expo=180s elev=21.5deg humid= 54% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +2.0 )
AL_20170531_234256448_000000_66772001     2 stars filter C [ 5862.1s -  6042.1s] expo=180s elev=21.8deg humid= 54% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +2.0 )
AL_20170531_234607167_000000_66772001     3 stars filter C [ 6052.9s -  6232.9s] expo=180s elev=22.1deg humid= 54% sunelev=-24.2deg (moon at 132.0deg phase=0.46 elev= +1.0 )
AL_20170531_234928370_000000_66772101    17 stars filter C [ 6254.1s -  6434.1s] expo=180s elev=22.5deg humid= 54% sunelev=-24.1deg (moon at 132.0deg phase=0.46 elev= +1.0 )
AL_20170531_235239569_000000_66772101     0 star  filter C [ 6445.3s -  6625.3s] expo=180s elev=22.8deg humid= 54% sunelev=-24.1deg (moon at 132.0deg phase=0.46 elev= +0.0 )
AL_20170531_235550100_000000_66772101    22 stars filter C [ 6635.8s -  6815.8s] expo=180s elev=23.1deg humid= 54% sunelev=-24.0deg (moon at 132.0deg phase=0.46 elev= +0.0 )
AL_20170531_235912241_000000_66772201    62 stars filter C [ 6837.9s -  7017.9s] expo=180s elev=23.5deg humid= 54% sunelev=-23.9deg (moon at 132.0deg phase=0.46 elev= +0.0 )
AL_20170601_000223440_000000_66772201     0 star  filter C [ 7029.1s -  7209.1s] expo=180s elev=23.8deg humid= 54% sunelev=-23.9deg (moon at 132.0deg phase=0.46 elev= -1.0 )
AL_20170601_000534393_000000_66772201    72 stars filter C [ 7220.1s -  7400.1s] expo=180s elev=24.1deg humid= 54% sunelev=-23.8deg (moon at 132.0deg phase=0.46 elev= -1.0 )
AL_20170601_000856768_000000_66772301     0 star  filter C [ 7422.5s -  7602.5s] expo=180s elev=24.4deg humid= 54% sunelev=-23.7deg (moon at 132.0deg phase=0.46 elev= -2.0 )
AL_20170601_001208016_000000_66772301    11 stars filter C [ 7613.7s -  7793.7s] expo=180s elev=24.7deg humid= 54% sunelev=-23.6deg (moon at 132.0deg phase=0.46 elev= -2.0 )
AL_20170601_001519000_000000_66772301    23 stars filter C [ 7804.7s -  7984.7s] expo=180s elev=25.0deg humid= 54% sunelev=-23.5deg (moon at 132.0deg phase=0.46 elev= -3.0 )
AL_20170601_001840891_000000_66772401    93 stars filter C [ 8006.5s -  8186.5s] expo=180s elev=25.3deg humid= 54% sunelev=-23.4deg (moon at 132.0deg phase=0.46 elev= -3.0 )
AL_20170601_002152044_000000_66772401    75 stars filter C [ 8197.8s -  8377.8s] expo=180s elev=25.5deg humid= 54% sunelev=-23.3deg (moon at 132.0deg phase=0.46 elev= -4.0 )
AL_20170601_002503060_000000_66772401   111 stars filter C [ 8388.7s -  8568.7s] expo=180s elev=25.8deg humid= 54% sunelev=-23.1deg (moon at 132.0deg phase=0.46 elev= -5.0 )
AL_20170601_002824450_000000_66772501   100 stars filter C [ 8590.2s -  8770.2s] expo=180s elev=26.1deg humid= 54% sunelev=-23.0deg (moon at 132.0deg phase=0.46 elev= -5.0 )
AL_20170601_003135724_000000_66772501   108 stars filter C [ 8781.4s -  8961.4s] expo=180s elev=26.3deg humid= 54% sunelev=-22.8deg (moon at 132.0deg phase=0.46 elev= -6.0 )
AL_20170601_003447364_000000_66772501   111 stars filter C [ 8973.0s -  9153.0s] expo=180s elev=26.5deg humid= 54% sunelev=-22.7deg (moon at 132.0deg phase=0.46 elev= -6.0 )
AL_20170601_003809474_000000_66772601    92 stars filter C [ 9175.2s -  9355.2s] expo=180s elev=26.8deg humid= 55% sunelev=-22.5deg (moon at 132.0deg phase=0.46 elev= -7.0 )
AL_20170601_004120428_000000_66772601   117 stars filter C [ 9366.1s -  9546.1s] expo=180s elev=27.0deg humid= 55% sunelev=-22.3deg (moon at 131.0deg phase=0.46 elev= -7.0 )
AL_20170601_004431225_000000_66772601    99 stars filter C [ 9556.9s -  9736.9s] expo=180s elev=27.2deg humid= 55% sunelev=-22.2deg (moon at 131.0deg phase=0.46 elev= -8.0 )
AL_20170601_004753288_000000_66772701   109 stars filter C [ 9759.0s -  9939.0s] expo=180s elev=27.4deg humid= 54% sunelev=-22.0deg (moon at 131.0deg phase=0.46 elev= -8.0 )
AL_20170601_005104734_000000_66772701   100 stars filter C [ 9950.5s - 10130.5s] expo=180s elev=27.6deg humid= 54% sunelev=-21.8deg (moon at 131.0deg phase=0.46 elev= -9.0 )
AL_20170601_005415734_000000_66772701    90 stars filter C [10141.4s - 10321.4s] expo=180s elev=27.8deg humid= 54% sunelev=-21.6deg (moon at 131.0deg phase=0.46 elev= -9.0 )
AL_20170601_005737172_000000_66772801   114 stars filter C [10342.8s - 10522.8s] expo=180s elev=28.0deg humid= 54% sunelev=-21.4deg (moon at 131.0deg phase=0.47 elev=-10.0 )
AL_20170601_010048140_000000_66772801    92 stars filter C [10533.8s - 10713.8s] expo=180s elev=28.2deg humid= 55% sunelev=-21.2deg (moon at 131.0deg phase=0.47 elev=-10.0 )
AL_20170601_010359111_000000_66772801   110 stars filter C [10724.8s - 10904.8s] expo=180s elev=28.4deg humid= 55% sunelev=-20.9deg (moon at 131.0deg phase=0.47 elev=-11.0 )
AL_20170601_010721032_000000_66772901   112 stars filter C [10926.5s - 11106.5s] expo=180s elev=28.5deg humid= 55% sunelev=-20.7deg (moon at 131.0deg phase=0.47 elev=-11.0 )
AL_20170601_011032345_000000_66772901    92 stars filter C [11117.7s - 11297.7s] expo=180s elev=28.7deg humid= 55% sunelev=-20.5deg (moon at 131.0deg phase=0.47 elev=-12.0 )
AL_20170601_011343672_000000_66772901   108 stars filter C [11309.4s - 11489.4s] expo=180s elev=28.8deg humid= 55% sunelev=-20.2deg (moon at 131.0deg phase=0.47 elev=-12.0 )
AL_20170601_011704859_000000_66773001    92 stars filter C [11510.5s - 11690.5s] expo=180s elev=28.9deg humid= 55% sunelev=-20.0deg (moon at 131.0deg phase=0.47 elev=-13.0 )
AL_20170601_012015891_000000_66773001   112 stars filter C [11701.5s - 11881.5s] expo=180s elev=29.1deg humid= 55% sunelev=-19.7deg (moon at 131.0deg phase=0.47 elev=-13.0 )
AL_20170601_012327131_000000_66773001   101 stars filter C [11892.7s - 12072.7s] expo=180s elev=29.2deg humid= 56% sunelev=-19.4deg (moon at 131.0deg phase=0.47 elev=-14.0 )
AL_20170601_012648803_000000_66773101    99 stars filter C [12094.4s - 12274.4s] expo=180s elev=29.3deg humid= 57% sunelev=-19.2deg (moon at 131.0deg phase=0.47 elev=-14.0 )
AL_20170601_012959975_000000_66773101   109 stars filter C [12285.6s - 12465.6s] expo=180s elev=29.4deg humid= 58% sunelev=-18.9deg (moon at 131.0deg phase=0.47 elev=-15.0 )
AL_20170601_013310930_000000_66773101    91 stars filter C [12476.6s - 12656.6s] expo=180s elev=29.5deg humid= 59% sunelev=-18.6deg (moon at 131.0deg phase=0.47 elev=-15.0 )
AL_20170601_013632368_000000_66773201   117 stars filter C [12678.0s - 12858.0s] expo=180s elev=29.6deg humid= 60% sunelev=-18.3deg (moon at 131.0deg phase=0.47 elev=-16.0 )
AL_20170601_013944462_000000_66773201   106 stars filter C [12870.1s - 13050.1s] expo=180s elev=29.6deg humid= 62% sunelev=-18.0deg (moon at 131.0deg phase=0.47 elev=-16.0 )
AL_20170601_014255429_000000_66773201    99 stars filter C [13061.1s - 13241.1s] expo=180s elev=29.7deg humid= 63% sunelev=-17.7deg (moon at 131.0deg phase=0.47 elev=-17.0 )
AL_20170601_014617116_000000_66773301   114 stars filter C [13262.8s - 13442.8s] expo=180s elev=29.8deg humid= 63% sunelev=-17.4deg (moon at 131.0deg phase=0.47 elev=-17.0 )
AL_20170601_014928100_000000_66773301    93 stars filter C [13453.8s - 13633.8s] expo=180s elev=29.8deg humid= 64% sunelev=-17.1deg (moon at 131.0deg phase=0.47 elev=-18.0 )
AL_20170601_015239496_000000_66773301   110 stars filter C [13645.2s - 13825.2s] expo=180s elev=29.8deg humid= 65% sunelev=-16.8deg (moon at 131.0deg phase=0.47 elev=-18.0 )
AL_20170601_020031012_000000_66773501   115 stars filter C [14116.7s - 14296.7s] expo=180s elev=29.9deg humid= 67% sunelev=-16.0deg (moon at 131.0deg phase=0.47 elev=-19.0 )
AL_20170601_020341843_000000_66773501   101 stars filter C [14307.5s - 14487.5s] expo=180s elev=29.9deg humid= 67% sunelev=-15.6deg (moon at 131.0deg phase=0.47 elev=-20.0 )
AL_20170601_020652578_000000_66773501   100 stars filter C [14498.2s - 14678.2s] expo=180s elev=29.9deg humid= 67% sunelev=-15.3deg (moon at 131.0deg phase=0.47 elev=-20.0 )
AL_20170601_021023953_000000_66773601   118 stars filter C [14709.6s - 14889.6s] expo=180s elev=29.9deg humid= 67% sunelev=-14.9deg (moon at 131.0deg phase=0.47 elev=-21.0 )
AL_20170601_021335664_000000_66773601    86 stars filter C [14901.3s - 15081.3s] expo=180s elev=29.8deg humid= 67% sunelev=-14.5deg (moon at 130.0deg phase=0.47 elev=-21.0 )
AL_20170601_021647554_000000_66773601   108 stars filter C [15093.2s - 15273.2s] expo=180s elev=29.8deg humid= 64% sunelev=-14.2deg (moon at 130.0deg phase=0.47 elev=-22.0 )
AL_20170601_022004133_000000_66773701    75 stars filter C [15289.8s - 15469.8s] expo=180s elev=29.8deg humid= 62% sunelev=-13.8deg (moon at 130.0deg phase=0.47 elev=-22.0 )
AL_20170601_022315270_000000_66773701     0 star  filter C [15481.0s - 15661.0s] expo=180s elev=29.7deg humid= 61% sunelev=-13.4deg (moon at 130.0deg phase=0.47 elev=-23.0 )
AL_20170601_022626942_000000_66773701     0 star  filter C [15672.6s - 15852.6s] expo=180s elev=29.6deg humid= 60% sunelev=-13.1deg (moon at 130.0deg phase=0.47 elev=-23.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457905.41816 2017-05-31T22:02:09.024
Decoded useful notice informations.
RA(J2000.0) : 286.8835 19h07m32s0
DEC(J2000.0) : -16.4192 -16d25m09s11
Error radius : 2.2 arcsec
Error box : x=76:77 y=73:74 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=19.9320348587 lat=-10.8956494341
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.567
Assuming Rv=3.1: Av=1.879 Ar=1.515 Ai=1.100
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 170531: 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 170531 detected by SWIFT
(trigger 755354) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 456.5s after the GRB trigger
(13.3s after the notice). The elevation of the field increased from
9 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2017-05-31T22:02:09.024

The first image is trailed with a duration of 30.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+456.5s to t0+486.5s : R > 15.1

The second image is 90.0s exposure in tracking mode:
t0+1170.4s to t0+1260.4s : R > 16.2

We co-added a series of exposures:
t0+1170.4s to t0+1772.3s : 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 456.5s 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= 19.9320 lat=-10.8956
and the galactic extinction in R band is 1.5 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

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