Gamma-ray Burst 180705A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 05 Jul 18 15:42:36 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     846299,   Seg_Num: 0
GRB_RA:          212.594d {+14h 10m 23s} (J2000),
                 212.843d {+14h 11m 22s} (current),
                 211.924d {+14h 07m 42s} (1950)
GRB_DEC:         -11.630d {-11d 37' 48"} (J2000),
                 -11.717d {-11d 43' 01"} (current),
                 -11.395d {-11d 23' 41"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1229 [image_cnts]
TRIGGER_DUR:     72.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        18304 TJD;   186 DOY;   18/07/05
GRB_TIME:        56474.78 SOD {15:41:14.78} UT
GRB_PHI:          -3.30 [deg]
GRB_THETA:        47.55 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.79 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  -2  +0  +0 +35  +0 
SUN_POSTN:       104.75d {+06h 58m 59s}  +22.74d {+22d 44' 38"}
SUN_DIST:        111.04 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        6.86d {+00h 27m 25s}   -2.06d {-02d 03' 24"}
MOON_DIST:       150.73 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.80, 46.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      214.36,  1.43 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 132.75,-13.82 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 05 Jul 18 15:45:32 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     846299,   Seg_Num: 0
GRB_RA:          212.594d {+14h 10m 23s} (J2000),
                 212.843d {+14h 11m 22s} (current),
                 211.924d {+14h 07m 42s} (1950)
GRB_DEC:         -11.630d {-11d 37' 48"} (J2000),
                 -11.717d {-11d 43' 01"} (current),
                 -11.395d {-11d 23' 41"} (1950)
GRB_DATE:        18304 TJD;   186 DOY;   18/07/05
GRB_TIME:        56474.78 SOD {15:41:14.78} UT
TRIGGER_INDEX:   20000
GRB_PHI:          -3.30 [deg]
GRB_THETA:        47.55 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     72.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    7.79 [sigma]
LC_URL:          sw00846299000msb.lc
SUN_POSTN:       104.75d {+06h 58m 59s}  +22.74d {+22d 44' 38"}
SUN_DIST:        111.04 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        6.88d {+00h 27m 31s}   -2.05d {-02d 02' 51"}
MOON_DIST:       150.75 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.80, 46.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      214.36,  1.43 [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 an image 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 = 132.75,-13.82 [deg].

GCN Circular #22902
M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC), A. A. Breeveld (UCL-MSSL), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU), S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 15:41:14 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180705A (trigger=846299). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 212.594, -11.630, which is
```
   RA(J2000)  =  14h 10m 23s
   Dec(J2000) = -11d 37' 48"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for image triggers, the real-time light curve does not show anything significant. The image trigger significance is 7.8 sigma, therefore we have high confidence in this event.
Due to an observing constraint, Swift will not slew until T0+54 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 05 Jul 18 16:37:34 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     846299,   Seg_Num: 0
POINT_RA:        212.601d {+14h 10m 24s} (J2000)
POINT_DEC:       -11.637d {-11d 38' 13"} (J2000)
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59838.45 SOD {16:37:18.45} UT,   3363.7 [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:     Thu 05 Jul 18 16:41:05 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     846299,   Seg_Num: 0
POINT_RA:        212.601d {+14h 10m 24s} (J2000)
POINT_DEC:       -11.637d {-11d 38' 13"} (J2000)
POINT_ROLL:      290.152d
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59841.63 SOD {16:37:21.63} UT,   3366.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.263
N_STARS:         43
X_OFFSET:        525 [pixels]
Y_OFFSET:        541 [pixels]
X_MAX:           1484 [pixels]
Y_MAX:           1500 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00846299000msufc3366.fits
SUN_POSTN:       104.79d {+06h 59m 09s}  +22.74d {+22d 44' 24"}
SUN_DIST:        111.01 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        7.33d {+00h 29m 20s}   -1.88d {-01d 52' 35"}
MOON_DIST:       151.22 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.81, 46.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      214.37,  1.42 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 05 Jul 18 16:41:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     846299,   Seg_Num: 0
POINT_RA:        212.601d {+14h 10m 24s} (J2000)
POINT_DEC:       -11.637d {-11d 38' 13"} (J2000)
POINT_ROLL:      290.152d
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59841.63 SOD {16:37:21.63} UT,   3366.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.263
N_STARS:         43
X_OFFSET:        525 [pixels]
Y_OFFSET:        541 [pixels]
X_MAX:           1484 [pixels]
Y_MAX:           1500 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00846299000msufc3366.fits
SUN_POSTN:       104.79d {+06h 59m 09s}  +22.74d {+22d 44' 24"}
SUN_DIST:        111.01 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        7.33d {+00h 29m 20s}   -1.88d {-01d 52' 32"}
MOON_DIST:       151.23 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.81, 46.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      214.37,  1.42 [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:     Thu 05 Jul 18 16:42:31 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     846299,   Seg_Num: 0
POINT_RA:        212.601d {+14h 10m 24s} (J2000)
POINT_DEC:       -11.637d {-11d 38' 13"} (J2000)
ROLL:            290.152d
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59841.63 SOD {16:37:21.63} UT,   3366.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     552501462
X_OFFSET:        844 [pixels]
Y_OFFSET:        860 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1004
Y_GRB_POS:       1020
BINNING_INDEX:   1
IM_URL:          sw00846299000msuni3388.fits
SUN_POSTN:       104.79d {+06h 59m 09s}  +22.74d {+22d 44' 24"}
SUN_DIST:        111.01 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        7.34d {+00h 29m 23s}   -1.87d {-01d 52' 19"}
MOON_DIST:       151.24 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.81, 46.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      214.37,  1.42 [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:     Thu 05 Jul 18 16:42:37 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     846299,   Seg_Num: 0
POINT_RA:        212.601d {+14h 10m 24s} (J2000)
POINT_DEC:       -11.637d {-11d 38' 13"} (J2000)
ROLL:            290.152d
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59841.63 SOD {16:37:21.63} UT,   3366.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     552501462
X_OFFSET:        844 [pixels]
Y_OFFSET:        860 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1004
Y_GRB_POS:       1020
BINNING_INDEX:   1
IM_URL:          sw00846299000msuni3388.fits
SUN_POSTN:       104.79d {+06h 59m 09s}  +22.74d {+22d 44' 24"}
SUN_DIST:        111.01 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        7.35d {+00h 29m 23s}   -1.87d {-01d 52' 18"}
MOON_DIST:       151.24 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.81, 46.76 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      214.37,  1.42 [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:     Thu 05 Jul 18 16:41:24 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     846299,   Seg_Num: 0
GRB_RA:          212.6132d {+14h 10m 27.16s} (J2000),
                 212.8619d {+14h 11m 26.85s} (current),
                 211.9423d {+14h 07m 46.16s} (1950)
GRB_DEC:         -11.6484d {-11d 38' 54.2"} (J2000),
                 -11.7351d {-11d 44' 06.2"} (current),
                 -11.4130d {-11d 24' 46.8"} (1950)
GRB_ERROR:       4.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18304 TJD;   186 DOY;   18/07/05
IMG_START_TIME:  59880.00 SOD {16:38:00.00} UT,   3405.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       104.79d {+06h 59m 09s}  +22.74d {+22d 44' 24"}
SUN_DIST:        111.02 [deg]   Sun_angle= -7.2 [hr] (East of Sun)
MOON_POSTN:        7.34d {+00h 29m 20s}   -1.88d {-01d 52' 31"}
MOON_DIST:       151.21 [deg]
MOON_ILLUM:      57 [%]
GAL_COORDS:      331.82, 46.74 [deg] galactic lon,lat of the burst
ECL_COORDS:      214.39,  1.42 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN Circular #22903
J.A. Kennea (PSU), G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester) and D.N. Burrows (PSU) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 180705A at 16:37:18.4 UT, 3363.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 212.61326, -11.64841 which is equivalent to:
```
   RA(J2000)  = 14h 10m 27.18s
   Dec(J2000) = -11d 38' 54.3"
```
with an uncertainty of 4.3 arcseconds (radius, 90% containment). This location is 94 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density.
GCN Circular #22904
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tiurina, A.Kuznetsov, V.Chazov, I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov Lomonosov Moscow State University,SAI
D. Buckley, South African Astronomical Observatory (SAAO)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC)
A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA)
H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU)
A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU)
MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) , located in South African Astronomical Observatory, was pointed to the Swift GRB180705A (BAT: Stamatikos et al. GCN 22902, GRBtime: 2018-07-05 15:41:14UT; XRT : RA,Dec2000=14h 10m 27.18s -11d 38' 54.3" Kennea et al. GCN22903) at 2018-07-05 15:54:52 ( GRB Altitude: 55.90, Sun: Altitude: -3.10) at sunset.
So MASTER-SAAO started GRB180705A observations at 2018-07-05 16:35:54UT (GRB altitute: 62.78, Sun: Altitude: -11.10).
MASTER automatic unfiltered (W=0.2B+0.8R by USNO-B1) limits are the following
```
T_start,UT             Exp,s    mlim   MASTER-II
2018-07-05 16:35:54	540	18.8	WEST
2018-07-05 16:35:54	180	17.9	WEST
2018-07-05 16:35:59	540	18.3	EAST
2018-07-05 16:35:59	180	17.5	EAST
2018-07-05 16:39:32	180	18.2	WEST
2018-07-05 16:39:37	180	17.9	EAST
2018-07-05 16:44:51	180	18.7	WEST
2018-07-05 16:44:56	180	18.4	EAST
2018-07-05 16:48:21	540	19.7	WEST
2018-07-05 16:48:21	180	18.8	WEST
2018-07-05 16:48:25	540	19.5	EAST
2018-07-05 16:48:25	180	18.5	EAST
2018-07-05 16:51:52	180	19.0	WEST
2018-07-05 16:51:56	180	18.8	EAST
2018-07-05 16:55:26	180	19.0	WEST
2018-07-05 16:55:30	180	18.8	EAST
2018-07-05 16:58:59	540	19.9	WEST
2018-07-05 16:58:59	180	19.3	WEST
2018-07-05 16:59:04	540	19.7	EAST
2018-07-05 16:59:04	180	19.0	EAST
2018-07-05 17:02:29	180	19.3	WEST
2018-07-05 17:02:34	180	19.0	EAST
2018-07-05 17:05:58	180	19.3	WEST
2018-07-05 17:06:03	180	19.0	EAST
2018-07-05 17:09:33	540	20.0	WEST
2018-07-05 17:09:33	180	19.3	WEST
2018-07-05 17:09:37	540	19.6	EAST
2018-07-05 17:09:37	180	19.0	EAST
2018-07-05 17:13:06	180	19.3	WEST
2018-07-05 17:13:10	180	19.1	EAST
2018-07-05 17:16:51	180	19.3	WEST
2018-07-05 17:16:56	180	19.0	EAST
2018-07-05 17:20:25	180	19.3	WEST
2018-07-05 17:20:29	180	19.0	EAST
```
The message may be cited.
GCN Circular #22906
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1348 s of XRT Photon Counting mode data and 4 UVOT images for GRB 180705A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 212.61323, -11.64745 which is equivalent to:
```
RA (J2000): 14h 10m 27.17s
Dec (J2000): -11d 38' 50.8"
```
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #22907
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180705A (trigger #846299) (Stamatikos et al., GCN Circ. 22902). The BAT ground-calculated position is RA, Dec = 212.605, -11.640 deg which is
```
  RA(J2000)  =  14h 10m 25.1s
  Dec(J2000) = -11d 38' 23.7"
```
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 36%.
The mask-weighted light curve shows some weak emission that starts at ~T0 and ends at ~T+130 s. However, the burst went out of the BAT FOV from T+158 s to T+204 s due to a preplanned slew, and thus there might be additional emission when the burst was out of the FOV. The burst came back in the BAT FOV shortly during the slew period (from T0+205 s to T0+262 s), though no emission are found during this time. T90 (15-350 keV) is 123.2 +- 16.6 sec (estimated error including systematics).
The time-averaged spectrum from T+0.26 to T+133.70 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.63 +- 0.22. The fluence in the 15-150 keV band is 2.0 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+3.60 sec in the 15-150 keV band is 0.7 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/846299/BA/
GCN Circular #22911
Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:
We observed the field of GRB 180705A (Stamatikos et al., GCN Circ. 22902) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2018/07 6.16 to 2018/07 6.27 UTC (12.19 to 14.82 hours after the BAT trigger), obtaining a total of 1.74 hours exposure in the r and i bands.
For a source within the Swift-XRT error circle (Kennea et al., GCN Circ. 22903), in comparison with the SDSS DR9 catalog, we obtain the following 3-sigma upper limits:
```
  r > 23.20=20
  i > 23.07
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #22912
A. A. Breeveld (UCL-MSSL), S. W. K Emery (UCL-MSSL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 180705A 3368 s after the BAT trigger (Stamatikos et al., GCN Circ. 22902). No optical afterglow consistent with the enhanced XRT position (Goad et al. GCN Circ. 22906) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          3368         3485          115         >20.2
white             3368         5327          312         >20.8
v                 4103         5738          393         >18.9
b                 4923        11649          311         >20.5
u                 4718        11527         1082         >21.0
w1                4513        16889          483         >20.5
m2                4308        15205          647         >20.1
w2                5333         5533          197         >20.4
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.06 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22913
E. Mazaeva (IKI), A. Pozanenko (IKI), A. Kusakin (FAPHI), I. Reva (FAPHI), A. Volnova (IKI), M. Krugov (FAPHI) report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 180705A (Stamatikos et al., GCN 22902) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on July 05 (UT) 16:13:52. We obtained several images in R-filter. Within enhanced XRT Swift-XRT position (Goad et al., GCN 22906) we do not detect any object. Preliminary photometry of the field is following.
```
Date        UT start t-T0     Filter Exp.    OT   Err.   UL
                      (mid, days)     (s)

2018-07-05  16:13:52 0.04895  R      25*120  n/d  n/d    21.3
```
The photometry is based on several nearby SDSS-DR12 stars.
Ref.stars
```
SDSS-DR12_id           R(Lupton)
J141030.67-113927.0    17.460
J141015.17-113809.7    17.680
```
GCN Circular #22920
A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC) and M. Stamatikos report on behalf of the Swift-XRT team:
We have analysed 5.7 ks of XRT data for GRB 180705A (Stamatikos et al. GCN Circ. 22902), from 3.4 ks to 56.6 ks after the BAT trigger. The data comprise 1.1 ks in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 22906).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.12 (+0.17, -0.13).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.99 (+0.32, -0.30). The best-fitting absorption column is 3.9 (+1.8, -1.5) x 10^21 cm^-2, in excess of the Galactic value of 5.8 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     3.9 (+1.8, -1.5) x 10^21 cm^-2
Galactic foreground: 5.8 x 10^20 cm^-2
Excess significance: 3.7 sigma
Photon index:	     1.99 (+0.32, -0.30)
```
If the light curve continues to decay with a power-law decay index of 1.12, the count rate at T+24 hours will be 6.4 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.5 x 10^-13 (3.8 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00846299.
This circular is an official product of the Swift-XRT team.
GCN Circular #22929
I. Bikmaev, E. Irtuganov, N. Sakhibullin (KFU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), I. Khamitov, S. Ozdemir (TUG), E. Gogus (Sabanci Uni.)
report:
We observed the field of GRB 180705A (Stamatikos et al., GCN 22902) with the Russian-Turkish 1.5-m optical telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey) using the TFOSC instrument.
We obtained series of Rc exposures in July 05, 2018 (6 frames x 600 sec, UT = 19:12 - 20:19), ~ 4 hours after the burst. Within enhanced Swift-XRT position (Goad et al., GCN 22906) we have not detected any object down to Rc =~ 23.5 mag in the combined image (calibrated against SDSS secondary standard stars). Our result confirms OT non-detections as published in other GCNs (Lipunov et al., GCN 22904, Watson et al., GCN 22911, Breeveld et al., GCN 22912, Mazaeva et al., GCN 22913).
GCN Circular #22941
D. A. Kann, L. Izzo (both HETH/IAA-CSIC), and A. Sota (IAA/CSIC) report on behalf of HETH:
We observed the field of GRB 180705A (Stamatikos et al., GCN #22902) with the 1.5-m OSN telescope in Granada, Spain.
We obtained 20 x 300 s images in the Ic band centered at 0.262416 days (6.3 hrs) after the GRB.
At the XRT position of the GRB (Goad et al., GCN #22906), there is a possible faint source, formally detected at Ic (Vega) = 23.6 +/- 0.2 mag. We note, however, that the background of the image is structured because of the proximity of the bright star HD 123921 (V ~ 9 mag), therefore the detection may be spurious. The formal 3 sigma upper limit is Ic > 24 mag, also possibly overestimated.
Even if the source we detect is not real, any afterglow of this GRB is clearly very faint, in agreement with other non-detection reports (Lipunov et al., GCN #22904, Watson et al., GCN #22911, Breeveld et al., GCN #22912, Mazaeva et al., GCN #22913, Bikmaev et al., GCN #22929).
The field was calibrated against SDSS secondary standard stars using the transformation of Lupton (2005).

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Jochen Greiner, last update: 11-Jul-2018 [Disclaimer]