image overlap message for exposure 3 of trigger 1426088
uvot_overlap.pl vrs. 2010-12-20b fem started at 251221d20h39m33s512673usUT
The observation of trigger 1426088 started 2025-12-21T05:39:46.8
Examining file ./1426088_g914_uvot_sky_image.fits
The exposure ID is 787988386
The exposure time is 149.868 (seconds)
The filter is WHITE.
The uvot region is centered at (101.4128,0.7225) with a roll angle of 154.0
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 (101.4080,0.7290) with a radius of 3.000 arc min
This is 0.483 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 (101.4277,0.7322) with a radius of 0.035 arc min
This is 1.064 arc min from the center of the uvot region
The area of the XRT error circle is 0.004 sq. arc min
The UVOT/XRT overlap is 0.004 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 3 of trigger 1426088
find_uvot_ag.pl vrs. 2023-04-25a fem started at 251221d20h40m17s421330usUT
Observation start time is 2025-12-21T05:39:46.8
Examining file ./1426088_g914_uvot_catalog_image.fits
The exposure ID is 787988386
The exposure is 149.868 sec.
The bin size is 2 pixels
The filter is WHITE
There are 36 detected source(s) for 1426088_g914
Aspect correction adds -0.00007 degrees (-0.017 sec of time = -0.25 arc sec) to RA
Aspect correction adds -0.00159 degrees (-5.72 arcsec) to Dec
Total aspect correction is 5.73 arcsec
Star catalogs centered at 101.4122 , 0.7233 with radius 2.72 arc min.
n_usno: 207 n_gsc: 253
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 36 matched entries is 0.502" for 1426088_g914
Mean and std. dev of mag. difference (MAG_DELTA) are 0.814 and 0.270 for 1426088_g914
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 1426088_g914.
Acceptable entries have no ID, XRT distances < 5.25", 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=101.4080 (06:45:37.92) DEC= 0.7290 (+00:43:44.4)
XRT distances are from RA=101.4277 (06:45:42.65) DEC= 0.7322 (+00:43:55.8)
-----------------
Entry 20 in the list of sources is a candidate afterglow for 1426088_g914 with genie
ra=101.39110 (06:45:33.86) dec=0.73806 (+00:44:17.0) +/- 0.6" mag=19.05+/-0.16
dist=133.5 REFID=4 major=0.6 minor=0.3 flag=16 (aperture_incomplete)
*** The position of this source is inconsistent with the XRT position.
The position is 69.0 arc sec from the BAT position.
This source is near the edge of image (1.010)
Found 7 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
101.3914 0.7334 16.9 -1 USNO-B1 19.61 17.35 18.35
101.3928 0.7366 8.1 -1 USNO-B1 19.77 17.95 18.76
101.3911 0.7338 15.3 -1 USNO-B1 18.70 17.66 18.12
101.3904 0.7382 2.6 -1 USNO-B1 15.46 14.39 14.86 *
101.3928 0.7366 8.3 -1 GSC2.3 18.31 19.60 99.99
101.3911 0.7338 15.3 -1 GSC2.3 17.42 18.75 99.99
101.3904 0.7382 2.7 -1 GSC2.3 13.74 15.13 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 3 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
101.4305 0.7322 10.0 -1 USNO-B1 20.62 19.41 19.95
101.4263 0.7321 5.0 -1 GSC2.3 20.33 99.99 99.99
101.4303 0.7323 9.4 -1 GSC2.3 19.23 21.11 99.99
The closest star is 4.97" away.
List UVOT sources within 10" of the XRT position:
There are 62842.281 counts in the bkg source region of 5337.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 11.775 counts/pixel (5-sig UL in 4" is 20.01 mag) for 1426088_g914
There are 2190.6570 counts in the xrt source region of 196.00000 pixels.
Rate in xrt region with 8 arcsec radius is 11.177 counts/pixel for 1426088_g914
XRT source is too far (63.9728865393637") from center -- do not compute local background.
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 20.57, XRT distances < 5.25",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 1426088_787988386_251221d20h40m17s421330usUT_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(101.4128,0.7225,45")
fk5;-circle(101.407372660735,0.728000685168401,6")
fk5;-circle(101.407954676771,0.73052820184493,6")
fk5;-circle(101.410127819804,0.726067786114932,6")
fk5;-circle(101.413662196707,0.726003199411224,6")
fk5;-circle(101.417848677734,0.729257722424329,6")
fk5;-circle(101.414335499024,0.718659622351872,6")
fk5;-circle(101.410085460035,0.716494035060073,6")
fk5;-circle(101.411825222947,0.716488142764166,6")
fk5;-circle(101.422132358962,0.722831746840085,6")
fk5;-circle(101.40916137002,0.709378930326353,6")
fk5;-circle(101.413899537897,0.708570058864464,6")
Region file: 1426088_787988386_251221d20h40m17s421330usUT_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(101.42771,0.73217,8")
image paragraph message for exposure 3 of trigger 1426088
SRCLIST PROBLEM: srclist filled telemetry buffer
WARNING -- because of the LARGE EXTINCTION, results should be used cautiously.
------ Start for Possible Stand-alone Circular ----
In response to GRB251221 (Swift/BAT trigger 1426088) at 05:24:31 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 877 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. The typical 3-sigma upper limit has been about 19.6 mag.
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 large, but uncertain, extinction expected.
------- notes for trigger 1426088 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 251221d20h40m27s098381usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1426088
-expid=787988386 -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/1426088/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
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 787988386.8155 or about 2025:356:05:39:41 UT
Found 2551 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 24% of the srclist region. Found 190 sources in
srclist catalog. WARNING -- srclist catalog buffer filled. Found 8 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 36 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 20.57 mag. Found 246 stars in largest star
catalog for Genie image region. The stars will eliminate afterglows from about
23% of the Genie image region.
Genie image analysis:
Found 62842.3 counts in the large background region of 5337.0 pixels or a rate
of 11.775 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 19.84 mag. for a
4-arcsec aperture.
Found 2190.7 counts in the XRT position region of 196.0 pixels or a rate of
11.177 counts/pixel in a radius of 8.0 arcsec. The net count rate (using large
background region) at the XRT position is -0.781 +/- 0.318 (1-sigma) cps. The
3-sigma UL at the XRT position is 0.954 cps or 19.66 mag. The number of srclist
sources filled the available telemetry. The weakest source detected was 18.79
mag. The closest srclist source has ra= 101.4310 dec= 0.7205 mag=17.52
sep=43.56". The closest Genie source has ra= 101.4327 dec= 0.7370 mag=18.60
sep=25.12".
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?
787988386 877 WHITE srclist found no candidates.
787988386 877 WHITE image found no candidates.
List afterglow candidates for other finding charts.
787987651 142 WHITE srclist found no candidates.
787987651 142 WHITE image found no candidates.
787987809 300 U srclist found no candidates.
787987809 300 U image found no candidates.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: 0.73217
GRB_ERROR: 5.25
GRB_RA: 101.42771
IMAGE_START_TIME: 05:39:41
MAGNITUDE: 19.7
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT