GRB120618_190647_SWIFT at TAROT Calern observatory

TAROT Calern observatory log of images

AL_20120618_225057206_000002_55526501    84 stars filter C [13264.8s - 13444.8s] expo=180s elev=33.2deg humid= 46% sunelev=-22.0deg (moon at 148.0deg phase=0.04 elev=-25.0 )
AL_20120618_225407971_000002_55526501    69 stars filter C [13455.6s - 13635.6s] expo=180s elev=33.5deg humid= 45% sunelev=-22.1deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_225718471_000002_55526501    49 stars filter R [13646.1s - 13826.1s] expo=180s elev=33.9deg humid= 46% sunelev=-22.2deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_230040087_000002_55526601    66 stars filter C [13847.7s - 14027.7s] expo=180s elev=34.2deg humid= 47% sunelev=-22.3deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_230350869_000002_55526601    54 stars filter C [14038.5s - 14218.5s] expo=180s elev=34.5deg humid= 47% sunelev=-22.4deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_230701556_000002_55526601    78 stars filter R [14229.2s - 14409.2s] expo=180s elev=34.9deg humid= 47% sunelev=-22.5deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_231032246_000002_55526701    66 stars filter C [14439.9s - 14619.9s] expo=180s elev=35.2deg humid= 47% sunelev=-22.6deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_231342996_000002_55526701    92 stars filter C [14630.6s - 14810.6s] expo=180s elev=35.5deg humid= 46% sunelev=-22.6deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_231654450_000002_55526701    80 stars filter R [14822.1s - 15002.1s] expo=180s elev=35.8deg humid= 44% sunelev=-22.7deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_232010956_000002_55526801    70 stars filter C [15018.6s - 15198.6s] expo=180s elev=36.1deg humid= 43% sunelev=-22.7deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_232322379_000002_55526801    99 stars filter C [15210.0s - 15390.0s] expo=180s elev=36.4deg humid= 43% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_232633409_000002_55526801    52 stars filter R [15401.0s - 15581.0s] expo=180s elev=36.7deg humid= 43% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_232951524_000002_55526901    87 stars filter C [15599.2s - 15779.2s] expo=180s elev=36.9deg humid= 43% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_233303024_000002_55526901    90 stars filter C [15790.6s - 15970.6s] expo=180s elev=37.2deg humid= 43% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-25.0 )
AL_20120618_233614149_000002_55526901    68 stars filter R [15981.8s - 16161.8s] expo=180s elev=37.4deg humid= 43% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-24.0 )
AL_20120618_234408154_000002_55527101    78 stars filter C [16455.8s - 16635.8s] expo=180s elev=38.0deg humid= 45% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-24.0 )
AL_20120618_234718452_000002_55527101   101 stars filter C [16646.1s - 16826.1s] expo=180s elev=38.2deg humid= 45% sunelev=-22.8deg (moon at 149.0deg phase=0.04 elev=-24.0 )
AL_20120618_235028941_000002_55527101    69 stars filter R [16836.6s - 17016.6s] expo=180s elev=38.4deg humid= 43% sunelev=-22.7deg (moon at 149.0deg phase=0.04 elev=-24.0 )
AL_20120619_000830870_000002_55527201    82 stars filter C [17918.5s - 18098.5s] expo=180s elev=39.4deg humid= 44% sunelev=-22.4deg (moon at 149.0deg phase=0.04 elev=-23.0 )
AL_20120619_001142297_000002_55527201    82 stars filter R [18109.9s - 18289.9s] expo=180s elev=39.6deg humid= 43% sunelev=-22.3deg (moon at 149.0deg phase=0.04 elev=-23.0 )
AL_20120619_001452780_000002_55527201    47 stars filter V [18300.4s - 18480.4s] expo=180s elev=39.7deg humid= 42% sunelev=-22.2deg (moon at 149.0deg phase=0.04 elev=-23.0 )
AL_20120619_003309351_000002_55527301    99 stars filter C [19397.0s - 19577.0s] expo=180s elev=40.3deg humid= 39% sunelev=-21.6deg (moon at 150.0deg phase=0.04 elev=-22.0 )
AL_20120619_003620085_000002_55527301    87 stars filter R [19587.8s - 19767.8s] expo=180s elev=40.3deg humid= 38% sunelev=-21.4deg (moon at 150.0deg phase=0.04 elev=-22.0 )
AL_20120619_003931766_000002_55527301    59 stars filter V [19779.4s - 19959.4s] expo=180s elev=40.4deg humid= 37% sunelev=-21.3deg (moon at 150.0deg phase=0.04 elev=-21.0 )
AL_20120619_005729850_000002_55527401   101 stars filter C [20857.5s - 21037.5s] expo=180s elev=40.5deg humid= 37% sunelev=-20.3deg (moon at 150.0deg phase=0.04 elev=-20.0 )
AL_20120619_010041042_000002_55527401    85 stars filter R [21048.7s - 21228.7s] expo=180s elev=40.5deg humid= 38% sunelev=-20.1deg (moon at 150.0deg phase=0.04 elev=-20.0 )
AL_20120619_010352433_000002_55527401    52 stars filter V [21240.1s - 21420.1s] expo=180s elev=40.4deg humid= 38% sunelev=-19.9deg (moon at 150.0deg phase=0.04 elev=-20.0 )
AL_20120619_012200896_000002_55527501   100 stars filter C [22328.5s - 22508.5s] expo=180s elev=40.1deg humid= 37% sunelev=-18.6deg (moon at 150.0deg phase=0.04 elev=-18.0 )
AL_20120619_012511928_000002_55527501    81 stars filter R [22519.5s - 22699.5s] expo=180s elev=40.0deg humid= 36% sunelev=-18.3deg (moon at 150.0deg phase=0.04 elev=-18.0 )
AL_20120619_012822630_000002_55527501    57 stars filter V [22710.3s - 22890.3s] expo=180s elev=39.9deg humid= 36% sunelev=-18.0deg (moon at 150.0deg phase=0.04 elev=-17.0 )
AL_20120619_014632173_000002_55527601    96 stars filter C [23799.8s - 23979.8s] expo=180s elev=39.1deg humid= 36% sunelev=-16.5deg (moon at 150.0deg phase=0.03 elev=-16.0 )
AL_20120619_014943633_000002_55527601    85 stars filter R [23991.3s - 24171.3s] expo=180s elev=38.9deg humid= 37% sunelev=-16.2deg (moon at 150.0deg phase=0.03 elev=-15.0 )
AL_20120619_015255054_000002_55527601    67 stars filter V [24182.7s - 24362.7s] expo=180s elev=38.7deg humid= 38% sunelev=-15.8deg (moon at 150.0deg phase=0.03 elev=-15.0 )
AL_20120619_021104142_000002_55527701    87 stars filter C [25271.8s - 25451.8s] expo=180s elev=37.5deg humid= 47% sunelev=-14.0deg (moon at 150.0deg phase=0.03 elev=-13.0 )
AL_20120619_021415173_000002_55527701    69 stars filter R [25462.8s - 25642.8s] expo=180s elev=37.3deg humid= 45% sunelev=-13.7deg (moon at 150.0deg phase=0.03 elev=-12.0 )
AL_20120619_021726797_000002_55527701    67 stars filter V [25654.4s - 25834.4s] expo=180s elev=37.0deg humid= 42% sunelev=-13.3deg (moon at 151.0deg phase=0.03 elev=-12.0 )
AL_20120619_023524152_000002_55527801    67 stars filter C [26731.8s - 26911.8s] expo=180s elev=35.5deg humid= 43% sunelev=-11.2deg (moon at 151.0deg phase=0.03 elev=-10.0 )
AL_20120619_023835120_000002_55527801    59 stars filter R [26922.8s - 27102.8s] expo=180s elev=35.2deg humid= 42% sunelev=-10.9deg (moon at 151.0deg phase=0.03 elev= -9.0 )
AL_20120619_024146577_000002_55527801    30 stars filter V [27114.2s - 27294.2s] expo=180s elev=34.8deg humid= 42% sunelev=-10.5deg (moon at 151.0deg phase=0.03 elev= -9.0 )
Informations from GCN notice:
This is a GRB
Date of the alert : 2456097.29638 2012-06-18T19:06:47.232
Decoded useful notice informations.
RA(J2000.0) : 287.5949 19h10m22s7
DEC(J2000.0) : -5.7988 -05d47m55s68
Error radius : 0.4 arcsec
Error box : x=44:44 y=73:73 (pixels)

Other pages about TAROT Calern observatory observations

Sum of images.
Differential photometry.

Galactic coordinates

Galactic coordinates : lon=29.887666 lat=-6.831589
NASA/IPAC-Extragalactic-Database tool for calculate an extinction

Extinction from Schlegel et al. (1998, ApJ 500, 525): E(B-V)=0.471
Assuming Rv=3.1: Av=1.562 Ar=1.260 Ai=0.914 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 120618: TAROT Calern observatory optical observations
Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 120618 detected by SWIFT
(trigger 524642) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 3.68h after the GRB trigger.
The elevation of the field increased from
33 degrees above horizon and weather conditions
were XXX.

---- NO
The date of trigger : t0 = 2012-06-18T19:06:47.232

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+13264.8s to t0+13444.8s : R > 15.1

The second image is 180.0s exposure in tracking mode:
t0+13455.6s to t0+13635.6s : R > 16.2

We co-added a series of exposures:
t0+13455.6s to t0+14619.9s : 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 3.68h 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= 29.8877 lat= -6.8316
and the galactic extinction in R band is 1.3 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.