image overlap message for exposure 1 of trigger 1308754
uvot_overlap.pl vrs. 2010-12-20b fem started at 250502d11h59m32s416615usUT
The observation of trigger 1308754 started 2025-04-30T17:34:17.3
Examining file ./1308754_g196_uvot_sky_image.fits
The exposure ID is 767727257
The exposure time is 149.868 (seconds)
The filter is WHITE.
The uvot region is centered at (233.4361,-18.0831) with a roll angle of 99.6
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 (233.4280,-18.0830) with a radius of 3.000 arc min
This is 0.464 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 (233.3870,-18.1185) with a radius of 0.038 arc min
This is 3.516 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 0.000 sq. arc min or 0.00 of the XRT error circle
image afterglow message for exposure 1 of trigger 1308754
find_uvot_ag.pl vrs. 2023-04-25a fem started at 250502d11h59m36s619883usUT
Observation start time is 2025-04-30T17:34:17.3
Examining file ./1308754_g196_uvot_catalog_image.fits
The exposure ID is 767727257
The exposure is 149.868 sec.
The bin size is 2 pixels
The filter is WHITE
There are 15 detected source(s) for 1308754_g196
Aspect correction adds 0.00109 degrees (0.261 sec of time = 3.72 arc sec) to RA
Aspect correction adds -0.00055 degrees (-1.99 arcsec) to Dec
Total aspect correction is 4.22 arcsec
Star catalogs centered at 233.4340 , -18.0882 with radius 2.68 arc min.
n_usno: 143 n_gsc: 101
*** 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 15 matched entries is 0.376" for 1308754_g196
Mean and std. dev of mag. difference (MAG_DELTA) are 0.917 and 0.519 for 1308754_g196
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1308754_g196.
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=233.4280 (15:33:42.72) DEC=-18.0830 (-18:04:58.8)
XRT distances are from RA=233.3870 (15:33:32.88) DEC=-18.1185 (-18:07:06.6)
Found 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
There are 63219.793 counts in the bkg source region of 5784.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 10.930 counts/pixel (5-sig UL in 4" is 20.05 mag) for 1308754_g196
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 20.61, 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: 1308754_767727257_250502d11h59m36s619883usUT_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(233.4361,-18.0831,45")
fk5;-circle(233.43779860197,-18.0844415603664,6")
fk5;-circle(233.438666917217,-18.0897340696831,6")
fk5;-circle(233.442278628425,-18.0807876439715,6")
fk5;-circle(233.443257134186,-18.079123846672,6")
fk5;-circle(233.446539666323,-18.0848099459015,6")
image paragraph message for exposure 1 of trigger 1308754
IMAGE PROBLEM: no overlap
------ Start for Possible Stand-alone Circular ----
In response to GRB250430 (Swift/BAT trigger 1308754) at 17:31:00 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 161 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 0.091.
------- notes for trigger 1308754 ------
uvot_gcn_auto.pl vrs. 2023-03-28 fem at 250502d11h59m42s892556usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1308754
-expid=767727257 -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/1308754/
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.
*** Warning -- BAT and XRT error circles do NOT overlap.
UVOT exposure began at MET 767727257.31966 or about 2025:121:17:34:12 UT
Found 805 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 14% of the srclist region. Found 76 sources in
srclist catalog. Found 4 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 15 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 20.61 mag. Found 139 stars in largest star
catalog for Genie image region. The stars will eliminate afterglows from about
13% of the Genie image region. The XRT position was OUTSIDE the star catalog
search region.
Genie image analysis:
Found 63219.8 counts in the large background region of 5784.0 pixels or a rate
of 10.930 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 19.88 mag. for a
4-arcsec aperture.
Found 1 srclist source(s) within 10.0" of the XRT position.
The brightest such source has ra= 233.3869 dec= -18.1184 mag=19.44 sep=0.53".
The closest srclist source has ra= 233.3869 dec= -18.1184 mag=19.44 sep=0.53".
The closest Genie source has ra= 233.4072 dec= -18.0834 mag=17.57 sep=144.07".
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 White filter
starting 161 seconds after the BAT trigger. There is a candidate afterglow in
the list of sources generated on-board at
RA(J2000) = 15:33:32.85 = 233.38688
DEC(J2000) = -18:07:06.2 = -18.11840
with a 90%-confidence error radius of about 1.10 arc sec. This position is 0.53
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.44 with a 1-sigma error of about 0.35. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.091.
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?
767727257 161 WHITE 233.38688 -18.11840 19.44/19.2 0.5 srclist Yes
767727257 161 WHITE image found no candidates.
List afterglow candidates for other finding charts.
------- Tokens for Quick GCN -------
CATALOG_TYPE: SRCLIST
FILTER: white
GRB_DEC: -18.11850
GRB_ERROR: 5.75
GRB_RA: 233.38700
IMAGE_START_TIME: 17:34:12
MAGNITUDE: 18.0
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT