GRB150428_031203_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20150428_031359902_000000_00000001     0 star  filter C [   -8.4s -    51.6s] expo= 60s elev=45.9deg humid= 91% sunelev=-13.2deg (moon at 139.0deg phase=0.63 elev=-15.0 )
AL_20150428_031417777_000000_00000001     0 star  filter C [   97.5s -   127.5s] expo= 30s elev=46.0deg humid= 91% sunelev=-12.9deg (moon at 139.0deg phase=0.63 elev=-15.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2457140.63337 2015-04-28T03:12:03.168
Decoded useful notice informations.
RA(J2000.0) : 292.6379 19h30m33s0
DEC(J2000.0) : 4.1253 +04d07m31s07
Error radius : 4.7 arcsec

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=41.1096015254 lat=-6.79305930502
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.273
Assuming Rv=3.1: Av=0.904 Ar=0.729 Ai=0.529
extmap.fit: 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
GRBlog
ROTSE last GRB images

Example of a GCNC email for this burst

gcncirc@capella.gsfc.nasa.gov
GRB 150428: 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 150428 detected by SWIFT
(trigger 639278) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started -8.4s after the GRB trigger
(-40.3s after the notice). The elevation of the field increased from
45 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2015-04-28T03:12:03.168

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+-8.4s to t0+51.6s : R > 15.1

The second image is 30.0s exposure in tracking mode:
t0+97.5s to t0+127.5s : R > 16.2

We co-added a series of exposures:
t0+97.5s to t0+127.5s : 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 -8.4s 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= 41.1096 lat= -6.7931
and the galactic extinction in R band is 0.7 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.
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