Gamma-ray Burst 070612B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 06:21:35 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     282073,   Seg_Num: 0
GRB_RA:          261.713d {+17h 26m 51s} (J2000),
                 261.815d {+17h 27m 16s} (current),
                 261.031d {+17h 24m 07s} (1950)
GRB_DEC:          -8.719d {-08d 43' 06"} (J2000),
                  -8.724d {-08d 43' 27"} (current),
                  -8.677d {-08d 40' 35"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5074 [cnts]    Image_Peak=182 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   147     E_range: 25-100 keV
BKG_INTEN:       30245 [cnts]
BKG_TIME:        22861.98 SOD {06:21:01.98} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14263 TJD;   163 DOY;   07/06/12
GRB_TIME:        22877.79 SOD {06:21:17.79} UT
GRB_PHI:          89.86 [deg]
GRB_THETA:        35.57 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     21.40 [sigma]
IMAGE_SIGNIF:    9.09 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2  +9  +0  +0 +96  +1 
SUN_POSTN:        80.13d {+05h 20m 32s}  +23.13d {+23d 07' 40"}
SUN_DIST:        165.51 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       37.68d {+02h 30m 42s}  +19.52d {+19d 31' 02"}
MOON_DIST:       135.99 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.05, 14.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      261.54, 14.48 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 344.40,17.05 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 06:24:53 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     282073,   Seg_Num: 0
GRB_RA:          261.713d {+17h 26m 51s} (J2000),
                 261.815d {+17h 27m 16s} (current),
                 261.031d {+17h 24m 07s} (1950)
GRB_DEC:          -8.719d {-08d 43' 06"} (J2000),
                  -8.724d {-08d 43' 27"} (current),
                  -8.677d {-08d 40' 35"} (1950)
GRB_DATE:        14263 TJD;   163 DOY;   07/06/12
GRB_TIME:        22877.79 SOD {06:21:17.79} UT
TRIGGER_INDEX:   147
GRB_PHI:          89.86 [deg]
GRB_THETA:        35.57 [deg]
DELTA_TIME:      20.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     21.40 [sigma]
IMAGE_SIGNIF:    9.09 [sigma]
LC_URL:          sw00282073000msb.lc
SUN_POSTN:        80.14d {+05h 20m 33s}  +23.13d {+23d 07' 41"}
SUN_DIST:        165.51 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       37.71d {+02h 30m 50s}  +19.53d {+19d 31' 45"}
MOON_DIST:       136.02 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.05, 14.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      261.54, 14.48 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 344.40,17.05 [deg].

GCN Circular #6511
D. Grupe (PSU), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU), W. B. Landsman (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL), J. L. Racusin (PSU), P. Romano (Univ. Bicocca & INAF-OAB) and M. C. Stroh (PSU) report on behalf of the Swift Team:
At 06:21:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070612B (trigger=282073). The BAT on-board calculated location is RA, Dec 261.713, -8.719 which is
```
   RA(J2000)  =  17h 26m 51s
   Dec(J2000) = -08d 43' 06"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showes a single peak with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger.
Because of an Earth limb constraint, the spacecraft did not slew promptly to the BAT position, and so there are no immediate XRT or UVOT data products to analyze. XRT and UVOT will begin observing this target at 07:13 UT.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:16:18 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     282073,   Seg_Num: 0
POINT_RA:        261.726d {+17h 26m 54s} (J2000)
POINT_DEC:        -8.754d {-08d 45' 13"} (J2000)
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26130.50 SOD {07:15:30.50} UT,   3252.7 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:17:48 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     282073,   Seg_Num: 0
POINT_RA:        261.726d {+17h 26m 54s} (J2000)
POINT_DEC:        -8.754d {-08d 45' 12"} (J2000)
POINT_ROLL:      5.674d
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26133.97 SOD {07:15:33.97} UT,   3256.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.269
N_STARS:         119
X_OFFSET:        640 [pixels]
Y_OFFSET:        353 [pixels]
X_MAX:           1599 [pixels]
Y_MAX:           1312 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00282073000msufc3256.fits
SUN_POSTN:        80.17d {+05h 20m 42s}  +23.13d {+23d 07' 50"}
SUN_DIST:        165.54 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       38.25d {+02h 32m 59s}  +19.72d {+19d 43' 08"}
MOON_DIST:       136.50 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.02, 14.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      261.55, 14.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:18:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     282073,   Seg_Num: 0
POINT_RA:        261.726d {+17h 26m 54s} (J2000)
POINT_DEC:        -8.754d {-08d 45' 12"} (J2000)
POINT_ROLL:      5.674d
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26133.97 SOD {07:15:33.97} UT,   3256.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.269
N_STARS:         119
X_OFFSET:        640 [pixels]
Y_OFFSET:        353 [pixels]
X_MAX:           1599 [pixels]
Y_MAX:           1312 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw00282073000msufc3256.fits
SUN_POSTN:        80.18d {+05h 20m 42s}  +23.13d {+23d 07' 50"}
SUN_DIST:        165.54 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       38.25d {+02h 33m 01s}  +19.72d {+19d 43' 16"}
MOON_DIST:       136.50 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.02, 14.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      261.55, 14.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:19:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     282073,   Seg_Num: 0
POINT_RA:        261.726d {+17h 26m 54s} (J2000)
POINT_DEC:        -8.754d {-08d 45' 12"} (J2000)
ROLL:            5.674d
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26133.97 SOD {07:15:33.97} UT,   3256.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     203325335
X_OFFSET:        959 [pixels]
Y_OFFSET:        672 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1119
Y_GRB_POS:       832
BINNING_INDEX:   1
IM_URL:          sw00282073000msuni3256.fits
SUN_POSTN:        80.18d {+05h 20m 42s}  +23.13d {+23d 07' 50"}
SUN_DIST:        165.54 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       38.26d {+02h 33m 02s}  +19.72d {+19d 43' 26"}
MOON_DIST:       136.51 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.02, 14.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      261.55, 14.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:19:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     282073,   Seg_Num: 0
POINT_RA:        261.726d {+17h 26m 54s} (J2000)
POINT_DEC:        -8.754d {-08d 45' 12"} (J2000)
ROLL:            5.674d
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26133.97 SOD {07:15:33.97} UT,   3256.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     203325335
X_OFFSET:        959 [pixels]
Y_OFFSET:        672 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1119
Y_GRB_POS:       832
BINNING_INDEX:   1
IM_URL:          sw00282073000msuni3256.fits
SUN_POSTN:        80.18d {+05h 20m 42s}  +23.13d {+23d 07' 50"}
SUN_DIST:        165.54 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       38.26d {+02h 33m 03s}  +19.73d {+19d 43' 31"}
MOON_DIST:       136.51 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.02, 14.34 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      261.55, 14.44 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Jun 07 07:31:18 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     282073,   Seg_Num: 0
GRB_RA:          261.7273d {+17h 26m 54.5s} (J2000),
                 261.8290d {+17h 27m 18.9s} (current),
                 261.0445d {+17h 24m 10.6s} (1950)
GRB_DEC:          -8.7518d {-08d 45' 06.4"} (J2000),
                  -8.7577d {-08d 45' 27.8"} (current),
                  -8.7101d {-08d 42' 36.3"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.54e-11 [erg/cm2/sec]
GRB_SIGNIF:      3.00 [sigma]
IMG_START_DATE:  14263 TJD;   163 DOY;   07/06/12
IMG_START_TIME:  26163.63 SOD {07:16:03.63} UT,   3285.8 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.19 261.35 242.66
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        80.18d {+05h 20m 44s}  +23.13d {+23d 07' 52"}
SUN_DIST:        165.54 [deg]   Sun_angle= 11.9 [hr] (West of Sun)
MOON_POSTN:       38.38d {+02h 33m 32s}  +19.77d {+19d 46' 02"}
MOON_DIST:       136.62 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:       15.02, 14.34 [deg] galactic lon,lat of the burst
ECL_COORDS:      261.56, 14.45 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values are not valid.   
COMMENTS:        ...

GCN Circular #6514
D. Grupe (PSU), P. Evans (U Leicester), report on behalf of the Swift Team:
Swift XRT started observing the afterglow of GRB 070612B (GCN circ 6511) at 07:15:15.59, 3239s after the BAT trigger. We found a bright, uncatalogued, possibly fading source in the XRT data.
Using 272 of prompt downlinked data, we find a position RA, Dec 261.7267, -8.7524 which is
```
   RA(J2000)  = 17 26 54.4
   Dec(J2000) = -08 45 08.7
```
with an uncertainty of 4.7 arcsec (radius, 90% containment). Further analysis of the data will be performed with the ground-processed data.
GCN Circular #6516
W. Li, R. J. Foley, D. A. Perley, J. S. Bloom, and A. V. Filippenko, University of California, Berkeley, on behalf of the KAIT GRB team, report:
The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory observed GRB 070612B detected with Swift (Trigger 282073; Grupe et al. GCN 6511). The automatic sequence started at 06:22:01, 44 s after the burst. The BAT location and the XRT position (Grupe & Evans GCN 6514) have been monitored in V, I, and clear filters, with varying exposure times. The observations are still on-going. Our image processing pipeline did not find any new objects within the XRT error circle, with the following photometry limits (calibrated with USNO B1.0). These magnitudes have not been corrected for Galactic extinction, which as estimated by the NED extinction calculator is approximately E(B-V) = 0.838 mag in this direction.
======================================================================
```
Start UT   t(GRB)   Filter    Exp(s)  3sigma-limit      

06:22:01     44s    clear      5.0      18.1 
06:22:09     52s    clear      5.0      18.2 
06:22:17     60s    clear      5.0      18.2 
06:22:25     68s    clear      5.0      18.1 
06:22:34     77s    clear      5.0      18.1 
06:22:42     85s    clear      5.0      18.1 
06:23:10    113s    V         15.0      17.1
06:23:36    139s    I         15.0      18.0
06:24:00    163s    clear     15.0      18.8
06:24:31    194s    V         45.0      17.6
06:25:27    250s    I         45.0      18.5
06:26:21    304     clear     45.0      19.3
```
========================================================================
More images, mostly 60 s exposures in the I and clear filters, have been obtained. No obvious OA was found in the XRT error circle to a limiting magnitude of 19.0 - 19.9 mag, at t= 304s to 6642s after the burst.
More analyses are in progress.
GCN Circular #6517
S. B. Cenko, A. Rau (Caltech) and D. B. Fox (Penn State) report on behalf of a larger collaboration:
We have imaged the field of GRB070612B (Grupe et al., GCN 6511) with the automated Palomar 60-inch telescope. Images were taken in the Kron R and Sloan i' and z' filters beginning approximately 12 minutes after the burst.
We find no sources inside the XRT error circle (Grupe and Evans, GCN 6514). Photometric calibration for the limits below was performed using USNO B-1 mangitudes converted to the SDSS photometric sytem using empirical relations from Jordi, Grebel & Ammon (A&A 460, 339, 2006):
```
t_b (min.)		Filter		Mag. Limit
-----------------------------------------------------------------------
21.2			i'		> 21.0
22.7			z'		> 20.5
```
We marginally detect a source just outside of the XRT error circle in our i' coaddition. The source, with i' magnitude ~ 22.0, is located at coordinates (J2000.0):
```
	RA: 17:26:54.936
	Dec: -08:45:08.35
```
This source is not present in either our R- our z'-band imaging of this field. Because of the faintness, we cannot assess the variability of this source at the present time.
GCN Circular #6518
Martin Jel=EDnek, Petr Kub=E1nek (IAA CSIC Granada, Spain),=20 and Michael Prouza (Columbia U. New York, USA and FZU Praha, Czech Rep.)=20 on behalf of the FRAM team, coordinated by FZU Praha, Czech Rep.
report
"The wide field camera of the telescope FRAM, located=20 at Pierre Auger observatory in Malargue, Argentina, followed the Swift GRB 070612B (Grupe et al. GCNs 6511 and 6514).
20s R-band (lambda_eff =3D 640nm, limmag =3D 14.8) images were obtained starting 62s after the GRB (45s after receiving the notification).
We do not detect any new source in single nor combined images within the BAT or XRT errorboxes."
this message may be cited
GCN Circular #6519
W. Landsman (NASA/GSFC) and D. Grupe (PSU) report on behalf of the Swift/UVOT team.
The Swift/UVOT observed the field of GRB 070612B starting 3256 s after the BAT trigger (Grupe et al., GCN Circ. 6511). The UVOT observations were delayed due to a Earth-limb constraint.
We do not find any source in any of the UVOT observations inside the refined XRT error circle (Grupe et al., GCN Circ. 6514). The 3-sigma upper limits for detecting a source in the first finding chart (FC) exposure and co-added frames are:
```
Filter    T_start(s)   T_stop(s)     Exp(s)     Mag (3-sigma UL)

Wh  (FC)   3256         3356          98          >20.3

Wh         3256         9882        1201          >21.7
V          3238        11624        1113          >20.0
B          4180         5813         393          >20.4
U          3975         5608         393          >20.1
UVW1       3772         5404         393          >20.1
UVM2       3567         5199         393          >20.0
UVW2       4590        10888        1082          >20.9
```
GCN Circular #6521
D. Grupe (PSU) reports on behalf of the Swift/XRT team
We have analyzed two orbits of GRB 070612B (Grupe et al., GCN 6509) with total observing times of 4.7 ks in Photon Counting mode in the Swift XRT. Due to Earth-constrain Swift did not slew immediately and XRT observations were delayed by almost one hour (Grupe \& Evans, GCN 6514). The Photon Counting mode image provides a refined XRT position at Ra, Dec= 261.7271, -8.7517, which is
```
RA(J2000) = 17h 26m 54.49s
Dec(J2000) = -08d 45' 06.3"
```
with an error of 4.0" (90% confidence). This position is 2.7 " away from the preliminary XRT position reported in GCN 6514.
The X-ray light curve shows a decaying source. While the afterglow is clearly detected in the first orbit, only a 3sigma upper limit of 0.012 counts/s can be given for the second orbit. Based on this result, we estimated a decay slope of 2.8+/-0.6.
The X-ray data can be fitted by a single power law with a photon index Gamma=1.7+-0.8 and the absorption column density fixed to the Galactic value of NH=1.68e21 cm-2 (Dickey & Lockman, 1990) with chi2/dof=4/3.
This circular is an official product of the Swift XRT team.
GCN Circular #6523
J. Cummings (GSFC/UMBC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 070612B (trigger #282073) (Grupe, et al., GCN Circ. 6511). The BAT ground-calculated position is RA, Dec = 261.716, -8.747 deg which is
```
   RA(J2000)  = 17h 26m 51.8s 
   Dec(J2000) = -8d 44' 48" 
```
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 17%.
The mask-weighted light curve shows a single roughly symetrical peak starting at T-5 sec, peaking at T+0 sec, and ending at T+12 sec. T90 (15-350 keV) is 13.5 +- 1 sec (estimated error including systematics).
The time-averaged spectrum from T-6.4 to T+10.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.11. The fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band is 2.6 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #6524
Adria C. Updike, Dieter H. Hartmann (Clemson University), Gary Henson (ETSU), Robert Mesler, Christina Bunker, and Jason Carson (ETSU/SARA REU program) report:
Using the 0.9m SARA telescope at Kitt Peak, we imaged the field of GRB 070612B (GCN 6511, Grupe et al.). Observations began 24 minutes after the trigger (282073) and consisted of 65 minutes of R-band images.
We do not detect any new sources in the refined XRT error box (GCN 6521, Grupe et al.) or at the position indicated by P60 (GCN 6517, Cenko et al.) down to a limiting magnitude of 20.6 +/- 0.6 in the R-band as calibrated relative to 10 USNO B1.0 stars.
The SARA Homepage can be found at: http://saraobservatory.org
This message may be cited.
GCN Report 65.1
GCN_Report 65.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_65_1.pdf by D. Grupe at PSU titled: "Swift observations of GRB 070612B"
GCN Circular #6541
G. Greco (Bologna University), F. Terra (Second University of Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University), G. Pizzichini (INAF/IASF Bologna), D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"), R. Gualandi (Bologna Observatory) report:
We imaged the field of GRB 070612B (Grupe et al., GCN 6511) with the 152 cm Loiano telescope in the Rc and Ic filters in clear sky conditions.
We do not detect any new sources in the combined images within the XRT error box (Grupe and Evans, GCN6514) with the following upper limits:
```
tmid (UT)        filter        Exp.       Limit
June 13.917        Rc         3x1800      22.2   (3 sigma)
June 13.975        Ic         3x1200      22.0   (3 sigma)
```
We detect the faint source indicated by Cenko et al. (GCN 6517 ) at an Ic-band magnitude of 21.9+/-0.16
Magnitude and upper limits were estimated by comparison with the USNO-B1 stars and are not corrected for galactic dust extinction.
The co-added Ic image, in which the comparison stars are marked, has been posted in our public directory from where it can be retrieved by sftp using
```
hostname: ermione.bo.astro.it
username: publicGRB
password: GRB_bo.
directory: GRB070612B
```
GCN Circular #6553
Y.kudo, T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Vasquez, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We observed the error box of GRB070612B (Grupe et al., GCN 6511) with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting at 11:46:53 June 12 UT, 5.1 hours after the trigger. In the co-added images of Ic, Rc, and g' bands, we did not detect any new source in the XRT error circle. The 3-sigma limiting magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band) stars are following.
```
Filter   start time   end time    Exp(s)    Mag (3-sigma upper limit)
-----------------------------------------------------------------
g'       11:46:53    12:16:35     25 x 60s     17.4
Rc       11:46:53    12:16:35     25 x 60s     18.6
Ic       11:46:53    12:16:35     25 x 60s     18.6
-----------------------------------------------------------------
```

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Jochen Greiner, last update: 18-Jun-2007 [Disclaimer]