image overlap message for exposure 2 of trigger 1073821
uvot_overlap.pl vrs. 2010-12-20b fem started at 210918d08h16m06s345089usUT
The observation of trigger 1073821 started 2021-09-18T08:13:15.9
Examining file 1073821_g894_uvot_sky_image.fits
The exposure ID is 653645595
The exposure time is 52.374 (seconds)
The filter is U.
*** Warning -- found 24237 null pixels in the image.
The uvot region is centered at (250.4603,-45.5432) with a roll angle of 282.4
It is square with sides of 2.68 arc min. for an area of 7.17 sq arc min
The BAT error circle is centered at (250.4550,-45.5400) with a radius of 3.000 arc min
This is 0.295 arc min from the center of the uvot region
The area of the BAT error circle is 28.27 sq. arc min
The UVOT/BAT overlap is 7.17 sq. arc min or 0.25 of the BAT error circle
The XRT error circle is centered at (250.4669,-45.5421) with a radius of 0.082 arc min
This is 0.285 arc min from the center of the uvot region
The area of the XRT error circle is 0.021 sq. arc min
The UVOT/XRT overlap is 0.00 sq. arc min or 0.00 of the XRT error circle
image afterglow message for exposure 2 of trigger 1073821
find_uvot_ag.pl vrs. 2020-10-30 fem started at 210918d08h16m08s635148usUT
Observation start time is 2021-09-18T08:13:15.9
Examining file 1073821_g894_uvot_sources_image.fits
The exposure ID is 653645595
The exposure is 52.374 sec.
The bin size is 2 pixels
The filter is U
There are 0 detected source(s) for 1073821_g894
*** WARNING -- Aspect solution FAILED.
Results need to be checked by, for example, blinking image with DS9.
Star catalogs centered at 250.4892 , -45.5443 with radius 2.00 arc min.
n_usno: 177 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1073821_g894.
Acceptable entries have no ID, XRT distances < 12.25", and are > 0.8*(80 - 10*(mag-6))" from any bright star
from any bright star and >21.6" from other rejected sources.
Magnitude criteria will be applied later.
BAT distances are from RA=250.4550 (16:41:49.20) DEC=-45.5400 (-45:32:24.0)
XRT distances are from RA=250.4669 (16:41:52.06) DEC=-45.5421 (-45:32:31.6)
Found 6 entries in star catalog(s) within 20" of the XRT position.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
250.4688 -45.5409 6.5 -1 USNO-B1 99.99 18.83 99.99
250.4681 -45.5398 9.0 -1 USNO-B1 19.63 18.66 19.09
250.4666 -45.5460 14.2 -1 USNO-B1 99.99 19.16 99.99
250.4660 -45.5445 9.1 -1 USNO-B1 19.74 18.16 18.86
250.4652 -45.5412 5.5 -1 USNO-B1 19.68 18.30 18.91
250.4647 -45.5373 18.0 -1 USNO-B1 16.28 15.05 15.60
The closest star is 5.49" away.
List UVOT sources within 20" of the XRT position:
There are 0.0000000 counts in the bkg source region of 0.0000000 pixels.
There are 0.0000000 counts in the xrt source region of 0.0000000 pixels.
There are 0.0000000 counts in the xrt_bkg source region of 0.0000000 pixels.
There are no candidates inside BAT error circle, but outside XRT error circle.
Good candidates have no ID, acceptable profiles,
mag between 9.01 and 17.47, XRT distances < 12.25",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Results are questionable because aspect solution FAILED.
Region file: 1073821_653645595_210918d08h16m08s635148usUT_bkg.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(250.4603,-45.5432,45")
Region file: 1073821_653645595_210918d08h16m08s635148usUT_xrt.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(250.4669,-45.5421,8")
Region file: 1073821_653645595_210918d08h16m08s635148usUT_xrt_bkg.region
# Region file format: DS9 version 3.0
global color=red font="helvetica 10 normal" select=1 edit=1 move=1 delete=1 include=1 fixed=0 source
fk5;circle(250.4669,-45.5421,25")
fk5;-circle(250.4669,-45.5421,15")
image paragraph message for exposure 2 of trigger 1073821
THIS MESSAGE IS *NOT* READY FOR DISTRIBUTION.
MORE ANALYSIS IS REQUIRED TO DETERMINE WHETHER THERE IS AN AFTERGLOW CANDIDATE.
IMAGE PROBLEM: no aspect solution
SRCLIST PROBLEM: no srclist afterglow info
See notes for more details.
WARNING -- because of the LARGE EXTINCTION, results should be used cautiously.
------ Start for Possible Stand-alone Circular ----
In response to GRB210918 (Swift/BAT trigger 1073821) at 07:58:20 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 52 seconds with the U filter starting
867 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image processing FAILED
because of no aspect solution. Results from the list of sources generated
on-board are not available at this time. No correction has been made for the
large, but uncertain, extinction expected.
------- notes for trigger 1073821 ------
uvot_gcn_auto.pl vrs. 2020-10-27 fem at 210918d08h16m18s117099usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1073821
-expid=653645595 -msg_image
Results from standard processing of UVOT TDRSS data for this trigger should be
available at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/1073821/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
Unreliable extinction found for bat position. Unreliable extinction found for
xrt position. XRT position found for Genie image. BAT position found.
UVOT exposure began at MET 653645595.86848 or about 2021:261:08:13:10 UT
No information found about the number of stars in the star catalog for srclist
region.
THERE IS NO ASPECT SOLUTION for the image data.
Found 0 source(s) in Genie image catalog. Found 0 Genie image source(s) without
IDs. There are 0 good candidate(s) in the Genie image catalog. Good candidates
must be brighter than 17.47 mag. Found 173 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 30% of the
Genie image region. The Genie image is INCOMPLETE with 24237 null pixels.
All AG candidates sorted by magnitude for the current finding chart.
(U/V/White SRCLIST mags < 17.5/17.5/18.5 are reliable. Mag > 18.5/18.5/19.5 are
not. Others are uncertain.)
(U/V/White Genie image mags < 18.0/18.0/19.0 are reliable. Mag > 19.0/19.0/20.0
are not. Others are uncertain.)
(Magnitudes followed by * have been corrected for exposure.)
---MET--- -dt- filter ---RA-- ---DEC--- -MAG/Limit Dist(") Source Asp.Corr?
653645595 867 U srclist data are not available.
653645595 867 U image found no candidates.
List afterglow candidates for other finding charts.
653644861 133 U srclist found no candidates.
653644861 133 U image found no candidates.
------- Tokens for Quick GCN -------