image overlap message for exposure 2 of trigger 1069169


uvot_overlap.pl vrs. 2010-12-20b fem started at 210818d05h22m11s350581usUT

The observation of trigger 1069169 started 2021-08-18T01:07:13.8
Examining file ./1069169_g305_uvot_sky_image.fits
The exposure ID is 650941633
The exposure time is 249.946 (seconds)
The filter is U.
*** Warning -- found 12298 null pixels in the image.

The uvot region is centered at (148.8181,-87.0207) with a roll angle of 358.6
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 (149.1310,-87.0310) with a radius of 3.000 arc min
This is 1.156 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 (148.8676,-87.0252) with a radius of 0.037 arc min
This is 0.315 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 0.00 sq. arc min or 0.00 of the XRT error circle



image afterglow message for exposure 2 of trigger 1069169


find_uvot_ag.pl vrs. 2020-10-30 fem started at 210818d05h22m24s923998usUT

Observation start time is 2021-08-18T01:07:13.8
Examining file ./1069169_g305_uvot_catalog_image.fits
The exposure ID is 650941633
The exposure is 249.946 sec.
The bin size is 2 pixels
The filter is U
There are 4 detected source(s) for 1069169_g305
Aspect correction adds -0.00591 degrees (-1.418 sec of time = -1.10 arc sec) to RA
Aspect correction adds 0.00023 degrees ( 0.84 arcsec) to Dec
Total aspect correction is 1.39 arcsec
Star catalogs centered at 148.6805 , -87.0245 with radius 2.20 arc min.
n_usno: 97 n_gsc: 0
*** WARNING -- bright star catalog has 1 entries brighter than 12 mag
The brightest has mag 11.35976
                        RA                      DEC              Mag  Color
bright star  0: 148.18330 (09:52:43.99) -87.00261 (-87:00:09.4) 11.36 USNO-V
Mean distance difference (CAT_DELTA) for 4 matched entries is 0.378" for 1069169_g305
Mean and std. dev of mag. difference (MAG_DELTA) are 1.500 and 0.450 for 1069169_g305
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1069169_g305.
Acceptable entries have no ID, XRT distances < 5.5", and are > 0.8*(80 - 10*(mag-6))" from any bright star
from any bright star and >21.6" from other rejected sources.
0 sources matched bright stars.
Magnitude criteria will be applied later.
BAT distances are from RA=149.1310 (09:56:31.44) DEC=-87.0310 (-87:01:51.6)
XRT distances are from RA=148.8676 (09:55:28.23) DEC=-87.0252 (-87:01:30.9)

Found 0 entries in star catalog(s) within 10" of the XRT position.

List UVOT sources within 10" of the XRT position:
There are 29746.953 counts in the bkg source region of 3328.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 8.938 counts/pixel (5-sig UL in 4" is 19.28 mag) for 1069169_g305
There are 0.0000000 counts in the xrt source region of 0.0000000 pixels.
There are 3237.1997 counts in the xrt_bkg source region of 354.00000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 9.145 counts/pixel (5-sig UL in 4" is 19.26 mag) for 1069169_g305

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 19.83, XRT distances < 5.5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.

SUMMARY: 0 good candidate(s) found.



Region file: 1069169_650941633_210818d05h22m24s923998usUT_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(148.8181,-87.0207,45")
fk5;-circle(148.645641239989,-87.027444029144,6")



Region file: 1069169_650941633_210818d05h22m24s923998usUT_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(148.86762,-87.02525,8")



Region file: 1069169_650941633_210818d05h22m24s923998usUT_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(148.86762,-87.02525,25")
fk5;-circle(148.86762,-87.02525,15")



image paragraph message for exposure 2 of trigger 1069169


IMAGE PROBLEM: no overlap

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

In response to GRB210818 (Swift/BAT trigger 1069169) at 01:02:07 UT,

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

UVOT took a finding chart exposure of 250 seconds with the U filter starting
278 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 18.0 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.213.

------- notes for trigger 1069169 ------
uvot_gcn_auto.pl vrs. 2020-10-27 fem at 210818d05h22m28s951152usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1069169
-expid=650941633 -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/1069169/
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 650941633.79022 or about 2021:230:01:07:08 UT

Found 710 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 13% of the srclist region. Found 37 sources in
srclist catalog. Found 5 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 4 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 19.83 mag. Found 93 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 13% of the
Genie image region. The Genie image is INCOMPLETE with 12298 null pixels.


Genie image analysis:
Found 29747.0 counts in the large background region of 3328.0 pixels or a rate
of 8.938 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 19.12 mag. for a
4-arcsec aperture.
Found 1 srclist source(s) within 10.0" of the XRT position.
The brightest such source has ra= 148.8637 dec= -87.0246 mag=18.21 sep=2.62".
The closest srclist source has ra= 148.8637 dec= -87.0246 mag=18.21 sep=2.62".
The closest Genie source has ra= 148.6456 dec= -87.0274 mag=17.11 sep=42.19".

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 250 seconds with the U filter starting
278 seconds after the BAT trigger. There is a candidate afterglow in the list
of sources generated on-board at
RA(J2000) = 09:55:27.29 = 148.86369
DEC(J2000) = -87:01:28.4 = -87.02455
with a 90%-confidence error radius of about 1.10 arc sec. This position is 2.62
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.21 with a 1-sigma error of about 0.35. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.213.

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?
650941633  277 U     148.86369	-87.02455  18.21/18.1	 2.6  srclist  Yes
650941633  277 U image found no candidates.
List afterglow candidates for other finding charts.
650941421   65 WHITE 148.86497	-87.02478  18.59/19.2	 1.7  srclist  Yes
650941421   65 WHITE 148.86729	-87.02467  17.93/20.1	 2.1  image    Yes
650942215  859 WHITE 148.86535	-87.02472  18.93/19.2	 1.2  srclist  Yes
650942215  859 WHITE 148.86762	-87.02478  18.17/20.3	 1.5  image    Yes

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

CATALOG_TYPE: SRCLIST
FILTER: u
GRB_DEC: -87.02525
GRB_ERROR: 5.5
GRB_RA: 148.86762
IMAGE_START_TIME: 01:07:08
MAGNITUDE: 18.0
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT