image overlap message for exposure 2 of trigger 1311764
uvot_overlap.pl vrs. 2010-12-20b fem started at 250510d01h53m25s137415usUT
The observation of trigger 1311764 started 2025-05-09T22:38:58.8
Examining file ./1311764_g327_uvot_sky_image.fits
The exposure ID is 768523138
The exposure time is 249.924 (seconds)
The filter is U.
The uvot region is centered at (46.4486,-38.8346) with a roll angle of 0.7
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 (46.4550,-38.8530) with a radius of 3.000 arc min
This is 1.143 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 (46.4497,-38.8420) with a radius of 0.038 arc min
This is 0.446 arc min from the center of the uvot region
The area of the XRT error circle is 0.005 sq. arc min
The UVOT/XRT overlap is 0.005 sq. arc min or 1.00 of the XRT error circle
image afterglow message for exposure 2 of trigger 1311764
find_uvot_ag.pl vrs. 2023-04-25a fem started at 250510d01h53m33s000694usUT
Observation start time is 2025-05-09T22:38:58.8
Examining file ./1311764_g327_uvot_catalog_image.fits
The exposure ID is 768523138
The exposure is 249.924 sec.
The bin size is 2 pixels
The filter is U
There are 1 detected source(s) for 1311764_g327
Aspect correction adds -0.00030 degrees (-0.072 sec of time = -0.84 arc sec) to RA
Aspect correction adds 0.00102 degrees ( 3.68 arcsec) to Dec
Total aspect correction is 3.77 arcsec
Star catalogs centered at 46.4273 , -38.8464 with radius 2.00 arc min.
n_usno: 33 n_gsc: 25
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 1 matched entries is 0.684" for 1311764_g327
Mean and std. dev of mag. difference (MAG_DELTA) are 0.472 and 0.000 for 1311764_g327
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1311764_g327.
Acceptable entries have no ID, XRT distances < 5.75", 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=46.4550 (03:05:49.20) DEC=-38.8530 (-38:51:10.8)
XRT distances are from RA=46.4497 (03:05:47.92) DEC=-38.8420 (-38:50:31.2)
Found 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
There are 71774.719 counts in the bkg source region of 6308.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 11.378 counts/pixel (5-sig UL in 4" is 19.14 mag) for 1311764_g327
There are 2269.8140 counts in the xrt source region of 196.00000 pixels.
Rate in xrt region with 8 arcsec radius is 11.581 counts/pixel for 1311764_g327
There are 14166.356 counts in the xrt_bkg source region of 1250.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 11.333 counts/pixel (5-sig UL in 4" is 19.15 mag) for 1311764_g327
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 19.70, XRT distances < 5.75",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 0 good candidate(s) found.
Region file: 1311764_768523138_250510d01h53m33s000694usUT_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(46.4486,-38.8346,45")
Region file: 1311764_768523138_250510d01h53m33s000694usUT_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(46.44967,-38.84200,8")
Region file: 1311764_768523138_250510d01h53m33s000694usUT_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(46.44967,-38.84200,25")
fk5;-circle(46.44967,-38.84200,15")
image paragraph message for exposure 2 of trigger 1311764
------ Start for Possible Stand-alone Circular ----
In response to GRB250509 (Swift/BAT trigger 1311764) at 22:33:30 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 250 seconds with the U filter starting
292 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.021.
------- notes for trigger 1311764 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 250510d01h53m38s798251usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1311764
-expid=768523138 -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/1311764/
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 768523138.78584 or about 2025:130:22:38:53 UT
Found 183 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 4% of the srclist region. Found 7 sources in
srclist catalog. Found 0 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 1 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 19.70 mag. Found 29 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 5% of the
Genie image region.
Genie image analysis:
Found 71774.7 counts in the large background region of 6308.0 pixels or a rate
of 11.378 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 18.94 mag. for a
4-arcsec aperture.
Found 2269.8 counts in the XRT position region of 196.0 pixels or a rate of
11.581 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 0.194 +/- 0.205 (1-sigma) cps or
19.92 mag and a range from 19.14 to 99.99 mag. The 3-sigma UL at the XRT
position is 0.808 cps or 18.37 mag. The closest srclist source has ra= 46.4219
dec= -38.8437 mag=16.83 sep=78.09". The closest Genie source has ra= 46.4221
dec= -38.8436 mag=16.20 sep=77.64".
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?
768523138 291 U srclist found no candidates.
768523138 291 U image found no candidates.
List afterglow candidates for other finding charts.
768522926 79 WHITE srclist found no candidates.
768522926 79 ? image data are not available.
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: -38.84200
GRB_ERROR: 5.75
GRB_RA: 46.44967
IMAGE_START_TIME: 22:38:53
MAGNITUDE: 18.4
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT