image overlap message for exposure 2 of trigger 921722


uvot_overlap.pl vrs. 2010-12-20b fem started at 190821d22h40m33s118767usUT

The observation of trigger 921722 started 2019-08-21T17:15:29.2
Examining file ./921722_g325_uvot_sky_image.fits
The exposure ID is 588100529
The exposure time is 126.706 (seconds)
The filter is U.

The uvot region is centered at (250.0509,-34.0095) with a roll angle of 274.9
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 (250.0770,-34.0220) with a radius of 3.000 arc min
This is 1.498 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 7.11 sq. arc min or 0.25 of the BAT error circle

The XRT error circle is centered at (250.0548,-34.0071) with a radius of 0.027 arc min
This is 0.242 arc min from the center of the uvot region
The area of the XRT error circle is 0.002 sq. arc min
The UVOT/XRT overlap is 0.002 sq. arc min or 1.00 of the XRT error circle



image afterglow message for exposure 2 of trigger 921722


find_uvot_ag.pl vrs. 2017-02-17 fem started at 190821d22h40m49s260965usUT

Observation start time is 2019-08-21T17:15:29.2
Examining file ./921722_g325_uvot_catalog_image.fits
The exposure ID is 588100529
The exposure is 126.706 sec.
The bin size is 2 pixels
The filter is U
There are 28 detected source(s) for 921722_g325
Aspect correction adds -0.00014 degrees (-0.033 sec of time = -0.41 arc sec) to RA
Aspect correction adds 0.00008 degrees ( 0.31 arcsec) to Dec
Total aspect correction is 0.51 arcsec
Star catalogs centered at 250.0523 , -34.0100 with radius 2.71 arc min.
n_usno: 535 n_gsc: 0
*** WARNING -- bright star catalog has 1 entries brighter than 12 mag
The brightest has mag 11.94
                        RA                      DEC              Mag  Color
bright star  0: 250.01719 (16:40:04.13) -34.01864 (-34:01:07.1) 11.94 USNO-R
Mean distance difference (CAT_DELTA) for 25 matched entries is 0.822" for 921722_g325
Mean and std. dev of mag. difference (MAG_DELTA) are 2.682 and 0.824 for 921722_g325
Found 4 entries without IDs and 4 entries that are acceptable afterglow candidates for 921722_g325.
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.
0 sources matched bright stars.
Magnitude criteria will be applied later.
BAT distances are from RA=250.0770 (16:40:18.48) DEC=-34.0220 (-34:01:19.2)
XRT distances are from RA=250.0548 (16:40:13.15) DEC=-34.0071 (-34:00:25.6)

-----------------
Entry 0 in the list of sources is a candidate afterglow for 921722_g325 with genie
 ra=250.05191 (16:40:12.46) dec=-34.00722 (-34:00:26.0) +/- 0.7" mag=18.39+/-0.19
 dist=8.6 REFID=12 major=1.1 minor=0.9 flag=0
*** The position of this source is inconsistent with the XRT position.
    The position is 91.8 arc sec from the BAT position.
Found 13 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 
  250.0489 -34.0111  16.7    -1 USNO-B1  19.09  18.88  18.97
  250.0523 -34.0069   1.8    -1 USNO-B1  17.34  15.71  16.44 *
  250.0548 -34.0076   8.7    -1 USNO-B1  99.99  17.80  99.99
  250.0550 -34.0077   9.4    -1 USNO-B1  99.99  17.84  99.99
  250.0527 -34.0067   3.0    -1 USNO-B1  99.99  16.92  99.99 *
  250.0481 -34.0111  18.1    -1 USNO-B1  99.99  20.40  99.99
  250.0526 -34.0058   5.5    -1 USNO-B1  18.03  17.29  17.62
  250.0477 -34.0076  12.6    -1 USNO-B1  17.19  15.45  16.22
  250.0466 -34.0095  17.8    -1 USNO-B1  18.67  17.16  17.83
  250.0495 -34.0052  10.2    -1 USNO-B1  99.99  17.64  99.99
  250.0574 -34.0061  16.7    -1 USNO-B1  17.87  17.77  17.81
  250.0543 -34.0041  13.2    -1 USNO-B1  99.99  18.46  99.99
  250.0488 -34.0030  17.7    -1 USNO-B1  99.99  18.59  99.99
Due to star catalog entries marked with *, this is probably NOT the afterglow
    These entries are within 3.5" or brighter than 12 mag

-----------------
Entry 1 in the list of sources is a candidate afterglow for 921722_g325 with genie
 ra=250.06531 (16:40:15.67) dec=-34.00982 (-34:00:35.4) +/- 0.9" mag=19.20+/-0.25
 dist=32.9 REFID=14 major=0.8 minor=0.8 flag=0
*** The position of this source is inconsistent with the XRT position.
    The position is 56.0 arc sec from the BAT position.
Found 14 entries in star catalog(s) within 20.0" of the candidate.
    RA        Dec    Sep. Match USNO/   USNO-B USNO-R USNO-V
                                GSC      GSC-F  GSC-J  GSC-V 
  250.0601 -34.0068  19.0    -1 USNO-B1  99.99  20.67  99.99
  250.0605 -34.0069  17.8    -1 USNO-B1  99.99  25.06  99.99
  250.0613 -34.0089  12.5    -1 USNO-B1  18.33  16.88  17.52
  250.0617 -34.0113  12.0    -1 USNO-B1  17.95  17.83  17.88
  250.0617 -34.0073  14.0    -1 USNO-B1  99.99  18.09  99.99
  250.0625 -34.0147  19.6    -1 USNO-B1  17.35  16.07  16.64
  250.0649 -34.0080   6.5    -1 USNO-B1  17.51  15.24  16.25
  250.0652 -34.0094   1.4    -1 USNO-B1  17.01  15.39  16.11 *
  250.0651 -34.0082   5.8    -1 USNO-B1  99.99  15.83  99.99
  250.0660 -34.0093   2.9    -1 USNO-B1  99.99  15.93  99.99 *
  250.0663 -34.0071  10.3    -1 USNO-B1  99.99  17.36  99.99
  250.0664 -34.0131  12.3    -1 USNO-B1  18.08  16.68  17.30
  250.0673 -34.0077   9.8    -1 USNO-B1  18.21  19.59  18.98
  250.0678 -34.0100   7.4    -1 USNO-B1  99.99  18.63  99.99
Due to star catalog entries marked with *, this is probably NOT the afterglow
    These entries are within 3.5" or brighter than 12 mag

-----------------
Entry 14 in the list of sources is a candidate afterglow for 921722_g325 with genie
 ra=250.08026 (16:40:19.26) dec=-34.00949 (-34:00:34.2) +/- 1.2" mag=19.93+/-0.38
 dist=76.5 REFID=13 major=0.8 minor=0.6 flag=0
*** The position of this source is inconsistent with the XRT position.
    The position is 46.1 arc sec from the BAT position.
This source is near the edge of image (0.902)
Found 10 entries in star catalog(s) within 20.0" of the candidate.
    RA        Dec    Sep. Match USNO/   USNO-B USNO-R USNO-V
                                GSC      GSC-F  GSC-J  GSC-V 
  250.0745 -34.0111  18.0    -1 USNO-B1  16.69  15.17  15.84
  250.0752 -34.0077  16.3    -1 USNO-B1  17.96  17.44  17.67
  250.0784 -34.0132  14.3    -1 USNO-B1  16.28  14.16  15.10
  250.0784 -34.0145  18.9    -1 USNO-B1  18.52  16.98  17.66
  250.0798 -34.0149  19.4    -1 USNO-B1  99.99  17.68  99.99
  250.0805 -34.0093   1.1    -1 USNO-B1  17.42  16.50  16.91 *
  250.0801 -34.0056  14.2    -1 USNO-B1  99.99  16.91  99.99
  250.0820 -34.0065  11.8    -1 USNO-B1  15.69  13.53  14.49
  250.0826 -34.0085   7.8    -1 USNO-B1  17.66  17.45  17.54
  250.0868 -34.0094  19.6    -1 USNO-B1  15.98  14.09  14.93
Due to star catalog entries marked with *, this is probably NOT the afterglow
    These entries are within 5.25" or brighter than 12 mag

-----------------
Entry 26 in the list of sources is a candidate afterglow for 921722_g325 with genie
 ra=250.05883 (16:40:14.12) dec=-34.03593 (-34:02:09.4) +/- 0.6" mag=15.93+/-0.14
 dist=104.5 REFID=1 major=1.0 minor=1.0 flag=0
*** The position of this source is inconsistent with the XRT position.
    The position is 73.9 arc sec from the BAT position.
This source is near the edge of image (0.885)
Found 7 entries in star catalog(s) within 20.0" of the candidate.
    RA        Dec    Sep. Match USNO/   USNO-B USNO-R USNO-V
                                GSC      GSC-F  GSC-J  GSC-V 
  250.0572 -34.0308  19.2    -1 USNO-B1  16.85  14.83  15.73
  250.0575 -34.0318  15.5    -1 USNO-B1  17.45  18.95  18.28
  250.0595 -34.0324  13.0    -1 USNO-B1  18.11  17.87  17.98
  250.0589 -34.0354   1.9    -1 USNO-B1  15.54  13.84  14.59 *
  250.0552 -34.0359  10.9    -1 USNO-B1  99.99  16.57  99.99
  250.0603 -34.0383   9.8    -1 USNO-B1  17.23  16.68  16.92
  250.0577 -34.0396  13.5    -1 USNO-B1  16.13  13.84  14.85
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 6 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
250.0523 -34.0069 7.4 -1 USNO-B1 17.34 15.71 16.44
250.0548 -34.0076 1.7 -1 USNO-B1 99.99 17.80 99.99
250.0550 -34.0077 2.1 -1 USNO-B1 99.99 17.84 99.99
250.0527 -34.0067 6.5 -1 USNO-B1 99.99 16.92 99.99
250.0526 -34.0058 8.0 -1 USNO-B1 18.03 17.29 17.62
250.0574 -34.0061 8.5 -1 USNO-B1 17.87 17.77 17.81
The closest star is 1.71" away.

List UVOT sources within 10" of the XRT position:
Unmatched source ra=250.05191 (16:40:12.46) dec=-34.00722 (-34:00:26.0) +/- 0.7" mag=18.39+/-0.19 dist=8.6 REFID=12 flag=0
There are 15755.421 counts in the bkg source region of 5998.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 2.627 counts/pixel (5-sig UL in 4" is 19.20 mag) for 921722_g325
There are 605.40253 counts in the xrt source region of 202.00000 pixels.
Rate in xrt region with 8 arcsec radius is 2.997 counts/pixel for 921722_g325
There are 3221.8989 counts in the xrt_bkg source region of 1248.0000 pixels.
Rate in xrt_bkg region from 15 to 25 arcsec is 2.582 counts/pixel (5-sig UL in 4" is 19.21 mag) for 921722_g325

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

SUMMARY: 0 good candidate(s) found.



Region file: 921722_588100529_190821d22h40m49s260965usUT_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(250.0509,-34.0095,45")
fk5;-circle(250.051909374318,-34.0072214290024,6")
fk5;-circle(250.065306429242,-34.009822576282,6")
fk5;-circle(250.040713184219,-33.9988013043195,6")
fk5;-circle(250.041292458604,-34.0165509588281,6")



Region file: 921722_588100529_190821d22h40m49s260965usUT_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(250.05479,-34.00711,8")



Region file: 921722_588100529_190821d22h40m49s260965usUT_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(250.05479,-34.00711,25")
fk5;-circle(250.05479,-34.00711,15")



image paragraph message for exposure 2 of trigger 921722


THIS MESSAGE IS *NOT* READY FOR DISTRIBUTION.
MORE ANALYSIS IS REQUIRED TO DETERMINE WHETHER THERE IS AN AFTERGLOW CANDIDATE.
IMAGE PROBLEM: high density of stars
SRCLIST PROBLEM: high density of stars
See notes for more details.
1 source(s) near the XRT position were rejected as afterglow candidate(s). See
notes for details.

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

In response to GRB190821 (Swift/BAT trigger 921722) at 17:10:03 UT,

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

UVOT took a finding chart exposure of 127 seconds with the U filter starting
301 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. Because of the density of catalogued stars, further analysis
is required to report an upper limit for any afterglow in the sub-image. The
8'x8' region for the list of sources generated on-board covers 100% of the XRT
error circle. Because of the density of catalogued stars, further analysis is
required to report an upper limit for any afterglow in the region. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.53.

------- notes for trigger 921722 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 190821d22h40m52s265329usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=921722
-expid=588100529 -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/921722/
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 588100529.24794 or about 2019:233:17:15:24 UT

Found 2932 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 57% of the srclist region. Found 91 sources in
srclist catalog. Found 15 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
17.75 mag.

Found 28 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 4 Genie image source(s) without IDs. There are 0 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
19.76 mag. Found 531 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 50% of the Genie image region.

Genie image analysis:
Found 15755.4 counts in the large background region of 5998.0 pixels or a rate
of 2.627 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 19.25 mag. for a
4-arcsec aperture.
Found 605.4 counts in the XRT position region of 202.0 pixels or a rate of
2.997 counts/pixel in a radius of 8.0 arcsec. The net count rate (using local
background region) at the XRT position is 0.661 +/- 0.207 (1-sigma) cps or
18.83 mag and a range from 18.53 to 19.24 mag. The 3-sigma UL at the XRT
position is 1.281 cps or 18.11 mag. The closest srclist source has ra= 250.0652
dec= -33.9979 mag=18.96 sep=45.34".
Found 1 Genie source(s) within 10.0" of the XRT position. The brightest such
source has ra= 250.0519 dec= -34.0072 mag=18.39 sep=8.61". The closest Genie
source has ra= 250.0519 dec= -34.0072 mag=18.39 sep=8.61".

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 127 seconds with the U filter starting
301 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 16:40:12.46 = 250.05191
DEC(J2000) = -34:00:26.0 = -34.00722
with a 90%-confidence error radius of about 0.71 arc sec. This position is 8.61
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.39 with a 1-sigma error of about 0.19. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.53.

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?
588100529  301 U srclist found no candidates.
588100529  301 U image found no candidates.
List afterglow candidates for other finding charts.
588100315   87 WHITE srclist found no candidates.
588100315   87 WHITE image found no candidates.

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