image overlap message for exposure 2 of trigger 1340954
uvot_overlap.pl vrs. 2010-12-20b fem started at 250809d17h15m46s049141usUT
The observation of trigger 1340954 started 2025-08-09T17:08:18.9
Examining file 1340954_g898_uvot_sky_image.fits
The exposure ID is 776452098
The exposure time is 149.868 (seconds)
The filter is U.
The uvot region is centered at (232.9898,-53.2953) with a roll angle of 277.0
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 (233.0150,-53.2890) with a radius of 3.000 arc min
This is 0.980 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 (233.0004,-53.2964) with a radius of 0.050 arc min
This is 0.385 arc min from the center of the uvot region
The area of the XRT error circle is 0.008 sq. arc min
The UVOT/XRT overlap is 0.008 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 2 of trigger 1340954
find_uvot_ag.pl vrs. 2023-04-25a fem started at 250809d17h15m46s985672usUT
Observation start time is 2025-08-09T17:08:18.9
Examining file 1340954_g898_uvot_catalog_image.fits
The exposure ID is 776452098
The exposure is 149.868 sec.
The bin size is 2 pixels
The filter is U
There are 22 detected source(s) for 1340954_g898
Aspect correction adds -0.00320 degrees (-0.769 sec of time = -6.90 arc sec) to RA
Aspect correction adds 0.00045 degrees ( 1.61 arcsec) to Dec
Total aspect correction is 7.08 arcsec
Star catalogs centered at 232.9971 , -53.2969 with radius 2.66 arc min.
n_usno: 898 n_gsc: 707
*** WARNING -- bright star catalog has 5 entries brighter than 12 mag
The brightest has mag 11.605
RA DEC Mag Color
bright star 0: 232.99638 (15:31:59.13) -53.29747 (-53:17:50.9) 11.61 USNO-R
bright star 1: 233.01616 (15:32:03.88) -53.29799 (-53:17:52.8) 11.82 USNO-R
bright star 2: 233.01242 (15:32:02.98) -53.32809 (-53:19:41.1) 11.87 USNO-V
bright star 3: 232.98600 (15:31:56.64) -53.26263 (-53:15:45.5) 11.85 USNO-R
bright star 4: 232.97952 (15:31:55.09) -53.33247 (-53:19:56.9) 11.86 GSC-F
Mean distance difference (CAT_DELTA) for 18 matched entries is 0.910" for 1340954_g898
Mean and std. dev of mag. difference (MAG_DELTA) are 2.427 and 0.887 for 1340954_g898
Found 6 entries without IDs and 1 entries that are acceptable afterglow candidates for 1340954_g898.
Acceptable entries have no ID, XRT distances < 7.5", and are > 0.8*(80 - 10*(mag-6))" from any bright star
from any bright star and >21.6" from other rejected sources.
5 sources matched bright stars.
Magnitude criteria will be applied later.
BAT distances are from RA=233.0150 (15:32:03.60) DEC=-53.2890 (-53:17:20.4)
XRT distances are from RA=233.0004 (15:32:00.10) DEC=-53.2963 (-53:17:46.7)
*** WARNING 27 per cent of entries have no IDs.
-----------------
Entry 12 in the list of sources is a candidate afterglow for 1340954_g898 with genie
ra=233.03161 (15:32:07.59) dec=-53.29357 (-53:17:36.9) +/- 0.8" mag=18.95+/-0.21
dist=67.9 REFID=7 major=1.0 minor=0.8 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 39.3 arc sec from the BAT position.
This source is near the edge of image (0.860)
Found 28 entries in star catalog(s) within 20.0" of the candidate.
printing all entries
(Entries within 2 arc sec of a source list entry are considered a match)
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
233.0252 -53.2960 16.2 -1 USNO-B1 99.99 16.86 99.99
233.0254 -53.2966 17.3 -1 USNO-B1 19.67 17.50 18.46
233.0253 -53.2955 15.3 -1 USNO-B1 18.62 17.13 17.79
233.0249 -53.2933 14.4 -1 USNO-B1 21.38 17.76 19.37
233.0271 -53.2921 11.1 -1 USNO-B1 99.99 16.87 99.99
233.0278 -53.2941 8.4 -1 USNO-B1 99.99 17.76 99.99
233.0299 -53.2949 6.2 -1 USNO-B1 19.31 17.59 18.35
233.0304 -53.2983 17.2 -1 USNO-B1 99.99 16.72 99.99
233.0304 -53.2949 5.4 -1 USNO-B1 20.93 18.10 19.36
233.0310 -53.2967 11.5 -1 USNO-B1 99.99 23.88 99.99
233.0320 -53.2938 1.2 -1 USNO-B1 17.01 15.38 16.10 *
233.0332 -53.2932 3.6 -1 USNO-B1 19.38 18.06 18.65 *
233.0328 -53.2913 8.7 -1 USNO-B1 20.27 17.73 18.86
233.0380 -53.2967 17.8 -1 USNO-B1 99.99 15.67 99.99
233.0370 -53.2898 18.0 -1 USNO-B1 99.99 16.90 99.99
233.0249 -53.2968 18.6 -1 GSC2.3 17.69 19.88 99.99
233.0251 -53.2952 15.3 -1 GSC2.3 17.21 19.02 99.99
233.0276 -53.2939 8.7 -1 GSC2.3 18.21 20.44 99.99
233.0270 -53.2920 11.3 -1 GSC2.3 19.62 99.99 99.99
233.0286 -53.2957 9.8 -1 GSC2.3 99.99 99.99 99.99
233.0302 -53.2951 6.3 -1 GSC2.3 18.62 99.99 99.99
233.0305 -53.2982 16.8 -1 GSC2.3 19.55 99.99 99.99
233.0318 -53.2935 0.3 -1 GSC2.3 15.64 17.14 16.48 *
233.0329 -53.2911 9.3 -1 GSC2.3 18.25 20.16 99.99
233.0338 -53.2930 5.0 -1 GSC2.3 99.99 99.99 99.99 *
233.0363 -53.2978 18.3 -1 GSC2.3 99.99 99.99 99.99
233.0379 -53.2966 17.5 -1 GSC2.3 19.65 21.83 99.99
233.0371 -53.2896 18.4 -1 GSC2.3 18.92 20.59 99.99
Due to star catalog entries marked with *, this is probably NOT the afterglow
These entries are within 5.25" or brighter than 12 mag
Found 10 entries in star catalog(s) within 10" of the XRT position.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
232.9971 -53.2968 7.3 -1 USNO-B1 12.86 11.62 12.17
232.9964 -53.2975 9.6 -1 USNO-B1 99.99 11.61 99.99
232.9991 -53.2968 3.3 -1 USNO-B1 16.76 15.36 15.98
232.9990 -53.2954 4.4 -1 USNO-B1 18.09 15.98 16.92
233.0004 -53.2969 2.0 -1 USNO-B1 99.99 16.70 99.99
232.9992 -53.2949 5.6 -1 USNO-B1 99.99 16.17 99.99
232.9992 -53.2963 2.7 -1 GSC2.3 16.42 99.99 99.99
233.0012 -53.2972 3.5 -1 GSC2.3 99.99 99.99 99.99
232.9992 -53.2946 6.7 -1 GSC2.3 16.65 18.73 17.10
233.0049 -53.2960 9.7 -1 GSC2.3 99.99 21.60 99.99
The closest star is 2.01" away.
List UVOT sources within 10" of the XRT position:
There are 12755.383 counts in the bkg source region of 5492.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 2.323 counts/pixel (5-sig UL in 4" is 19.45 mag) for 1340954_g898
There are 684.72479 counts in the xrt source region of 198.00000 pixels.
Rate in xrt region with 8 arcsec radius is 3.458 counts/pixel for 1340954_g898
There are 2633.6140 counts in the xrt_bkg source region of 1056.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 2.494 counts/pixel (5-sig UL in 4" is 19.41 mag) for 1340954_g898
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 20.01, XRT distances < 7.5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 1340954_776452098_250809d17h15m46s985672usUT_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(232.9898,-53.2953,45")
fk5;-circle(232.995969862562,-53.2971877023928,6")
fk5;-circle(233.007029368941,-53.2997068497077,6")
fk5;-circle(232.996325518816,-53.2987101261165,6")
fk5;-circle(233.009736923095,-53.2910077140709,6")
fk5;-circle(232.991286547126,-53.301570061551,6")
fk5;-circle(232.994956703688,-53.303675052776,6")
fk5;-circle(232.97707354848,-53.2965555838066,6")
fk5;-circle(232.975161345673,-53.2899944121876,6")
fk5;-circle(232.97051380649,-53.2883273236623,6")
fk5;-circle(232.96864213364,-53.2983710470681,6")
Region file: 1340954_776452098_250809d17h15m46s985672usUT_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(233.0004,-53.2963,8")
Region file: 1340954_776452098_250809d17h15m46s985672usUT_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(233.0004,-53.2963,25")
fk5;-circle(233.0004,-53.2963,15")
fk5;-circle(232.995969862562,-53.2971877023928,6")
fk5;-circle(233.007029368941,-53.2997068497077,6")
fk5;-circle(232.996325518816,-53.2987101261165,6")
fk5;-circle(233.009736923095,-53.2910077140709,6")
fk5;-circle(232.991286547126,-53.301570061551,6")
fk5;-circle(232.994956703688,-53.303675052776,6")
image paragraph message for exposure 2 of trigger 1340954
THIS MESSAGE IS *NOT* READY FOR DISTRIBUTION.
MORE ANALYSIS IS REQUIRED TO DETERMINE WHETHER THERE IS AN AFTERGLOW CANDIDATE.
IMAGE PROBLEM: high density of stars
SRCLIST PROBLEM: high density of stars, srclist filled telemetry buffer
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 GRB250809 (Swift/BAT trigger 1340954) at 16:53:19 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the U filter starting
863 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the
XRT error circle. Because of the density of catalogued stars, further analysis
is required to report an upper limit for any afterglow in the sub-image. The
8'x8' region for the list of sources generated on-board covers 100% of the XRT
error circle. Because of the density of catalogued stars, further analysis is
required to report an upper limit for any afterglow in the region. No
correction has been made for the large, but uncertain, extinction expected.
------- notes for trigger 1340954 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 250809d17h15m48s655393usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1340954
-expid=776452098 -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/1340954/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
Large extinction of 6.364 found for bat position. Unreliable extinction found
for xrt position. XRT position found for srclist. XRT position found for Genie
image. BAT position found.
UVOT exposure began at MET 776452098.88546 or about 2025:222:17:08:13 UT
Since the srclist star catalog filled its buffer, the sensitivity for an
afterglow may be REDUCED. The stars will eliminate afterglows from about 63%
or more of the srclist region. Found 190 sources in srclist catalog. WARNING --
srclist catalog buffer filled. Found 50 srclist source(s) without IDs. There
are 0 good candidate(s) in the srclist catalog. Good candidates must be
brighter than 18.12 mag.
Found 22 source(s) in Genie image catalog. Found 6 Genie image source(s)
without IDs. There are 0 good candidate(s) in the Genie image catalog. Good
candidates must be brighter than 20.01 mag. Found 894 stars in largest star
catalog for Genie image region. The stars will eliminate afterglows from about
87% of the Genie image region.
Genie image analysis:
Found 12755.4 counts in the large background region of 5492.0 pixels or a rate
of 2.323 counts/pixel in a radius of 45.0 arcsec. Based on this background, the
typical 5-sigma UL at a random point in the Genie image is 19.25 mag. for a
4-arcsec aperture.
Found 684.7 counts in the XRT position region of 198.0 pixels or a rate of
3.458 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 1.273 +/- 0.186 (1-sigma) cps or
17.87 mag and a range from 17.72 to 18.04 mag. The 3-sigma UL at the XRT
position is 1.830 cps or 17.48 mag. The number of srclist sources filled the
available telemetry. The weakest source detected was 18.52 mag.
Found 1 srclist source(s) within 10.0" of the XRT position.
The brightest such source has ra= 232.9966 dec= -53.2972 mag=17.65 sep=8.74".
The closest srclist source has ra= 232.9966 dec= -53.2972 mag=17.65 sep=8.74".
The closest Genie source has ra= 232.9960 dec= -53.2972 mag=15.65 sep=10.05".
Report rejected UVOT sources within 10 arcsec XRT position.
Such sources are usually NOT the afterglow.
****THIS SOURCE NEAR XRT POSITION WAS REJECTED--USE WITH CAUTION****
UVOT took a finding chart exposure of 150 seconds with the U filter starting
863 seconds after the BAT trigger. There is a candidate afterglow in the list
of sources generated on-board at
RA(J2000) = 15:31:59.18 = 232.99659
DEC(J2000) = -53:17:49.8 = -53.29717
with a 90%-confidence error radius of about 1.10 arc sec. This position is 8.74
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.65 with a 1-sigma error of about 0.35. No correction has been made for the
large, but uncertain, extinction expected.
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?
776452098 862 U srclist found no candidates.
776452098 862 U image found no candidates.
List afterglow candidates for other finding charts.
776451363 127 U srclist found no candidates.
776451363 127 U image found no candidates.
------- Tokens for Quick GCN -------