image overlap message for exposure 2 of trigger 1351008


uvot_overlap.pl vrs. 2010-12-20b fem started at 250920d17h04m15s009995usUT

The observation of trigger 1351008 started 2025-09-20T08:52:18.1
Examining file ./1351008_g347_uvot_sky_image.fits
The exposure ID is 780051138
The exposure time is 140.948 (seconds)
The filter is U.

The uvot region is centered at (187.3162,47.8315) with a roll angle of 192.9
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 (187.3370,47.8440) with a radius of 3.000 arc min
This is 1.123 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 (187.3169,47.8375) with a radius of 0.032 arc min
This is 0.358 arc min from the center of the uvot region
The area of the XRT error circle is 0.003 sq. arc min
The UVOT/XRT overlap is 0.003 sq. arc min or 1.00 of the XRT error circle



image afterglow message for exposure 2 of trigger 1351008


find_uvot_ag.pl vrs. 2023-04-25a fem started at 250920d17h04m26s042717usUT

Observation start time is 2025-09-20T08:52:18.1
Examining file ./1351008_g347_uvot_catalog_image.fits
The exposure ID is 780051138
The exposure is 140.948 sec.
The bin size is 2 pixels
The filter is U
There are 2 detected source(s) for 1351008_g347
Aspect correction adds -0.00073 degrees (-0.175 sec of time = -1.77 arc sec) to RA
Aspect correction adds 0.00103 degrees ( 3.69 arcsec) to Dec
Total aspect correction is 4.09 arcsec
Star catalogs centered at 187.3154 , 47.8363 with radius 2.14 arc min.
n_usno: 57 n_gsc: 20
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 1 matched entries is 0.677" for 1351008_g347
Mean and std. dev of mag. difference (MAG_DELTA) are 1.476 and 0.000 for 1351008_g347
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 1351008_g347.
Acceptable entries have no ID, XRT distances < 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=187.3370 (12:29:20.88) DEC=47.8440 (+47:50:38.4)
XRT distances are from RA=187.3169 (12:29:16.05) DEC=47.8375 (+47:50:15.0)
*** WARNING 50 per cent of entries have no IDs.

-----------------
Entry 0 in the list of sources is a candidate afterglow for 1351008_g347 with genie
 ra=187.31701 (12:29:16.08) dec=47.83737 (+47:50:14.5) +/- 0.7" mag=13.32+/-0.14
 dist=0.6 REFID=1 major=0.8 minor=0.8 flag=0
Found 0 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)
uvot_check_outside found 12 of 12 good pixels
##### This source remains a candidate #####
    It has no entries 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:
Unmatched source ra=187.31701 (12:29:16.08) dec=47.83737 (+47:50:14.5) +/- 0.7" mag=13.32+/-0.14 dist=0.6 REFID=1 flag=0
There are 28258.285 counts in the bkg source region of 6206.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 4.553 counts/pixel (5-sig UL in 4" is 19.02 mag) for 1351008_g347
There are 7488.3867 counts in the src source region of 52.000000 pixels.
Rate in src region with 4 arcsec radius is 144.007 counts/pixel for 1351008_g347
There are 6009.5571 counts in the cand_src_bkg source region of 1251.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 4.804 counts/pixel (5-sig UL in 4" is 18.99 mag) for 1351008_g347

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 19.57, XRT distances < 5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.

SUMMARY: 1 good candidate(s) found.



Region file: 1351008_780051138_250920d17h04m26s042717usUT_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(187.3162,47.8315,45")
fk5;-circle(187.317005753959,47.8373689236954,6")



Region file: 1351008_780051138_250920d17h04m26s042717usUT_cand_src.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(187.317005753959,47.8373689236954,4")



Region file: 1351008_780051138_250920d17h04m26s042717usUT_cand_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(187.317005753959,47.8373689236954,25")
fk5;-circle(187.317005753959,47.8373689236954,15")



image paragraph message for exposure 2 of trigger 1351008



------ Start for Possible Stand-alone Circular ----

In response to GRB250920 (Swift/BAT trigger 1351008) at 08:46:30 UT,

---- UVOT paragraph for Joint or Stand-alone Circular ----

UVOT took a finding chart exposure of 141 seconds with the U filter starting
311 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 12:29:16.08 = 187.31701
DEC(J2000) = +47:50:14.5 = 47.83737
with a 90%-confidence error radius of about 0.74 arc sec. This position is 0.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
13.32 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.011.

------- notes for trigger 1351008 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 250920d17h04m31s280194usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1351008
-expid=780051138 -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/1351008/
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 780051138.0665 or about 2025:264:08:52:13 UT

Found 362 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 6% of the srclist region. Found 8 sources in
srclist catalog. Found 3 srclist source(s) without IDs. There are 1 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
17.81 mag.

Found 2 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 1 Genie image source(s) without IDs. There are 1 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
19.57 mag. Found 53 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 8% of the Genie image region.

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?
780051138  311 U     187.31707	47.83733  14.36/17.8	0.8  srclist  Yes
780051138  311 U     187.31701	47.83737  13.32/19.6	0.6  image    Yes
List afterglow candidates for other finding charts.
780050925   98 WHITE 187.31690	47.83727  13.86/19.2	0.8  srclist  Yes
780050925   98 WHITE 187.31697	47.83734  13.75/20.1	0.6  image    Yes

------- Tokens for Quick GCN -------

CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: 47.83737
GRB_ERROR: 0.74
GRB_RA: 187.31701
IMAGE_START_TIME: 08:52:13
MAGNITUDE: 13.32
MAG_ERROR: 0.14
MESSAGE_TYPE: ACK
SOURCE: XRT