GRB151023_134305_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20151023_172759161_000003_57087501     0 star  filter C [13309.6s - 13489.6s] expo=180s elev=31.7deg humid= 51% sunelev=-9.5deg (moon at  66.0deg phase=0.71 elev=+28.0 )
AL_20151023_173109476_000003_57087501     0 star  filter C [13499.9s - 13679.9s] expo=180s elev=31.3deg humid= 51% sunelev=-10.0deg (moon at  66.0deg phase=0.71 elev=+28.0 )
AL_20151023_173419992_000003_57087501    12 stars filter R [13690.4s - 13870.4s] expo=180s elev=31.0deg humid= 51% sunelev=-10.6deg (moon at  66.0deg phase=0.71 elev=+28.0 )
AL_20151023_173744429_000003_57087601    15 stars filter C [13894.9s - 14074.9s] expo=180s elev=30.6deg humid= 51% sunelev=-11.2deg (moon at  66.0deg phase=0.71 elev=+29.0 )
AL_20151023_174055428_000003_57087601    28 stars filter C [14085.8s - 14265.8s] expo=180s elev=30.3deg humid= 52% sunelev=-11.8deg (moon at  66.0deg phase=0.71 elev=+29.0 )
AL_20151023_174406850_000003_57087601    23 stars filter R [14277.3s - 14457.3s] expo=180s elev=29.9deg humid= 51% sunelev=-12.4deg (moon at  66.0deg phase=0.71 elev=+29.0 )
AL_20151023_174728960_000003_57087701    32 stars filter C [14479.4s - 14659.4s] expo=180s elev=29.5deg humid= 51% sunelev=-13.0deg (moon at  66.0deg phase=0.71 elev=+30.0 )
AL_20151023_175039727_000003_57087701    33 stars filter C [14670.1s - 14850.1s] expo=180s elev=29.2deg humid= 51% sunelev=-13.6deg (moon at  66.0deg phase=0.71 elev=+30.0 )
AL_20151023_175350227_000003_57087701    23 stars filter R [14860.7s - 15040.7s] expo=180s elev=28.8deg humid= 50% sunelev=-14.1deg (moon at  66.0deg phase=0.71 elev=+31.0 )
AL_20151023_175713992_000003_57087801    38 stars filter C [15064.4s - 15244.4s] expo=180s elev=28.4deg humid= 50% sunelev=-14.7deg (moon at  66.0deg phase=0.71 elev=+31.0 )
AL_20151023_180024733_000003_57087801    41 stars filter C [15255.1s - 15435.1s] expo=180s elev=28.0deg humid= 50% sunelev=-15.3deg (moon at  66.0deg phase=0.71 elev=+31.0 )
AL_20151023_180335952_000003_57087801    21 stars filter R [15446.4s - 15626.4s] expo=180s elev=27.6deg humid= 50% sunelev=-15.9deg (moon at  66.0deg phase=0.71 elev=+32.0 )
AL_20151023_181712394_000003_57087901    35 stars filter C [16262.8s - 16442.8s] expo=180s elev=25.9deg humid= 50% sunelev=-18.4deg (moon at  67.0deg phase=0.71 elev=+33.0 )
AL_20151023_182023866_000003_57087901    29 stars filter R [16454.3s - 16634.3s] expo=180s elev=25.4deg humid= 50% sunelev=-18.9deg (moon at  67.0deg phase=0.71 elev=+33.0 )
AL_20151023_182335304_000003_57087901    10 stars filter V [16645.7s - 16825.7s] expo=180s elev=25.0deg humid= 50% sunelev=-19.5deg (moon at  67.0deg phase=0.71 elev=+34.0 )
AL_20151023_184152661_000003_57088001    23 stars filter C [17742.9s - 17922.9s] expo=180s elev=22.5deg humid= 50% sunelev=-22.8deg (moon at  67.0deg phase=0.71 elev=+35.0 )
AL_20151023_184504098_000003_57088001    21 stars filter R [17934.4s - 18114.4s] expo=180s elev=22.0deg humid= 50% sunelev=-23.4deg (moon at  67.0deg phase=0.71 elev=+35.0 )
AL_20151023_184815536_000003_57088001     7 stars filter V [18125.8s - 18305.8s] expo=180s elev=21.6deg humid= 50% sunelev=-24.0deg (moon at  67.0deg phase=0.71 elev=+36.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457319.07158 2015-10-23T13:43:04.512
Decoded useful notice informations.
RA(J2000.0) : 270.9846 18h03m56s3
DEC(J2000.0) : -8.3164 -08d18m59s03
Error radius : 3.2 arcsec
Error box : x=102:104 y=71:73 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=20.0545491089 lat=6.5847500079
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=1.387
Assuming Rv=3.1: Av=4.598 Ar=3.708 Ai=2.691 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 151023: TAROT Calern observatory optical observations
Klotz A., Turpin D. (IRAP-CNRS-OMP),
Boer M., Gendre B., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 151023 detected by SWIFT
(trigger 661253) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 3.70h after the GRB trigger.
The elevation of the field decreased from
31 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2015-10-23T13:43:04.512

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+13309.6s to t0+13489.6s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+13499.9s to t0+13679.9s : R > 16.2

We co-added a series of exposures:
t0+13499.9s to t0+14659.4s : 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 3.70h 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= 20.0545 lat= +6.5848
and the galactic extinction in R band is 3.7 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.