image overlap message for exposure 2 of trigger 1344131
uvot_overlap.pl vrs. 2010-12-20b fem started at 250821d18h25m02s448581usUT
The observation of trigger 1344131 started 2025-08-21T11:01:25.0
Examining file ./1344131_g906_uvot_sky_image.fits
The exposure ID is 777466884
The exposure time is 149.857 (seconds)
The filter is WHITE.
The uvot region is centered at (358.4201,-28.6208) with a roll angle of 117.2
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 (358.4120,-28.6180) with a radius of 3.000 arc min
This is 0.460 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 (358.4398,-28.6533) with a radius of 0.043 arc min
This is 2.204 arc min from the center of the uvot region
The area of the XRT error circle is 0.006 sq. arc min
The UVOT/XRT overlap is 0.000 sq. arc min or 0.00 of the XRT error circle
image afterglow message for exposure 2 of trigger 1344131
find_uvot_ag.pl vrs. 2023-04-25a fem started at 250821d18h25m43s045574usUT
Observation start time is 2025-08-21T11:01:25.0
Examining file ./1344131_g906_uvot_catalog_image.fits
The exposure ID is 777466884
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is WHITE
There are 4 detected source(s) for 1344131_g906
Aspect correction adds 0.00089 degrees (0.215 sec of time = 2.82 arc sec) to RA
Aspect correction adds -0.00077 degrees (-2.78 arcsec) to Dec
Total aspect correction is 3.97 arcsec
Star catalogs centered at 358.4096 , -28.6177 with radius 2.18 arc min.
n_usno: 56 n_gsc: 50
*** WARNING -- XRT position is outside star catalog search region.
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 3 matched entries is 0.788" for 1344131_g906
Mean and std. dev of mag. difference (MAG_DELTA) are 0.762 and 0.766 for 1344131_g906
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 1344131_g906.
Acceptable entries have no ID, XRT distances < 6.5", 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=358.4120 (23:53:38.88) DEC=-28.6180 (-28:37:04.8)
XRT distances are from RA=358.4398 (23:53:45.54) DEC=-28.6533 (-28:39:11.8)
-----------------
Entry 1 in the list of sources is a candidate afterglow for 1344131_g906 with genie
ra=358.41056 (23:53:38.53) dec=-28.61052 (-28:36:37.9) +/- 0.8" mag=20.23+/-0.19
dist=179.5 REFID=3 major=1.3 minor=1.1 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 27.3 arc sec from the BAT position.
Found 3 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
358.4112 -28.6104 2.1 -1 USNO-B1 20.60 20.72 20.67 *
358.4127 -28.6062 16.9 -1 USNO-B1 99.99 20.15 99.99
358.4111 -28.6103 1.9 -1 GSC2.3 20.17 20.99 99.99 *
Due to star catalog entries marked with *, this is probably NOT the afterglow
These entries are within 3.5" or brighter than 12 mag
Found 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
There are 45176.930 counts in the bkg source region of 6184.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 7.305 counts/pixel (5-sig UL in 4" is 20.27 mag) for 1344131_g906
Do not compute counts in XRT region because position is too far from center.
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 20.82, XRT distances < 6.5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 1344131_777466884_250821d18h25m43s045574usUT_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(358.4201,-28.6208,45")
fk5;-circle(358.408788512342,-28.6230971064671,6")
fk5;-circle(358.410558072565,-28.6105179635157,6")
image paragraph message for exposure 2 of trigger 1344131
IMAGE PROBLEM: no overlap
------ Start for Possible Stand-alone Circular ----
In response to GRB250821 (Swift/BAT trigger 1344131) at 10:46:17 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 871 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 none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.015.
------- notes for trigger 1344131 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 250821d18h25m48s423621usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1344131
-expid=777466884 -meonly -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/1344131/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
XRT position found for srclist. XRT position found for Genie image. BAT
position found.
UVOT exposure began at MET 777466884.95684 or about 2025:234:11:01:19 UT
Found 799 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 7% of the srclist region. Found 60 sources in
srclist catalog. Found 19 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
19.22 mag.
Found 4 source(s) in Genie image catalog. Found 1 Genie image source(s) without
IDs. There are 0 good candidate(s) in the Genie image catalog. Good candidates
must be brighter than 20.82 mag. Found 52 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 7% of the
Genie image region. The XRT position was OUTSIDE the star catalog search
region.
Genie image analysis:
Found 45176.9 counts in the large background region of 6184.0 pixels or a rate
of 7.305 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 20.10 mag. for a
4-arcsec aperture. The closest srclist source has ra= 358.4514 dec= -28.6364
mag=19.47 sep=71.14". The closest Genie source has ra= 358.4054 dec= -28.6357
mag=19.93 sep=125.74".
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?
777466884 870 WHITE srclist found no candidates.
777466884 870 WHITE image found no candidates.
List afterglow candidates for other finding charts.
777466160 146 WHITE srclist found no candidates.
777466160 146 WHITE image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: SRCLIST
FILTER: white
GRB_DEC: -28.65328
GRB_ERROR: 6.5
GRB_RA: 358.43975
IMAGE_START_TIME: 11:01:19
MAGNITUDE: 18.0
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT