image overlap message for exposure 2 of trigger 992444
uvot_overlap.pl vrs. 2010-12-20b fem started at 200821d13h31m53s577199usUT
The observation of trigger 992444 started 2020-08-21T13:20:41.5
Examining file 992444_g335_uvot_sky_image.fits
The exposure ID is 619708841
The exposure time is 249.935 (seconds)
The filter is U.
The uvot region is centered at (353.5769,-48.2808) with a roll angle of 145.2
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 (353.5700,-48.2770) with a radius of 3.000 arc min
This is 0.356 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
Could not find the location of an XRT error circle
image afterglow message for exposure 2 of trigger 992444
find_uvot_ag.pl vrs. 2017-02-17 fem started at 200821d13h31m54s884989usUT
Observation start time is 2020-08-21T13:20:41.5
Examining file 992444_g335_uvot_catalog_image.fits
The exposure ID is 619708841
The exposure is 249.935 sec.
The bin size is 2 pixels
The filter is U
There are 6 detected source(s) for 992444_g335
Aspect correction adds 0.00204 degrees (0.491 sec of time = 4.90 arc sec) to RA
Aspect correction adds -0.00157 degrees (-5.66 arcsec) to Dec
Total aspect correction is 7.49 arcsec
Star catalogs centered at 353.5761 , -48.2850 with radius 2.47 arc min.
n_usno: 29 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
*** WARNING -- no XRT distances are available.
Mean distance difference (CAT_DELTA) for 5 matched entries is 0.489" for 992444_g335
Mean and std. dev of mag. difference (MAG_DELTA) are 1.012 and 0.662 for 992444_g335
Found 1 entries without IDs and 1 entries that are acceptable afterglow candidates for 992444_g335.
Acceptable entries have no ID, BAT distance < 200" or XRT distance < 10", 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=353.5700 (23:34:16.80) DEC=-48.2770 (-48:16:37.2)
XRT distances are as reported in catalog file.
-----------------
Entry 4 in the list of sources is a candidate afterglow for 992444_g335 with genie
ra=353.60212 (23:34:24.51) dec=-48.27456 (-48:16:28.4) +/- 0.8" mag=19.92+/-0.23
dist=77.5 REFID=3 major=1.1 minor=0.9 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 13 of 13 good pixels
##### This source remains a candidate #####
It has no entries within 3.5" or brighter than 12 mag
There are 11345.262 counts in the bkg source region of 6308.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 1.799 counts/pixel (5-sig UL in 4" is 20.15 mag) for 992444_g335
There are 141.74144 counts in the src source region of 51.000000 pixels.
Rate in src region with 4 arcsec radius is 2.779 counts/pixel for 992444_g335
source too far from center -- do not compute local background.
Good candidates have no ID, acceptable profiles,
mag between 9.01 and 20.14, BAT distances < 200",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 1 good candidate(s) found.
Region file: 992444_619708841_200821d13h31m54s884989usUT_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(353.5769,-48.2808,45")
Region file: 992444_619708841_200821d13h31m54s884989usUT_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(353.602116264229,-48.2745551144962,4")
image paragraph message for exposure 2 of trigger 992444
------ Start for Possible Stand-alone Circular ----
In response to GRB200821 (Swift/BAT trigger 992444) at 13:15:05 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 250 seconds with the U filter starting
310 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 23:34:24.51 = 353.60212
DEC(J2000) = -48:16:28.4 = -48.27456
with a 90%-confidence error radius of about 0.83 arc sec. This position is 77.5
arc sec. from the center of the BAT error circle. The estimated magnitude is
19.92 with a 1-sigma error of about 0.23. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01.
------- notes for trigger 992444 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 200821d13h31m56s663462usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=992444
-expid=619708841 -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/992444/
Links to data for all triggers can be found at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/
No XRT position found for srclist. No XRT position found for Genie image. BAT
position found.
UVOT exposure began at MET 619708841.46444 or about 2020:234:13:20:36 UT
Found 360 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 3% of the srclist region. Found 44 sources in
srclist catalog. Found 8 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
17.56 mag.
Found 6 source(s) in Genie image catalog. 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 20.14 mag. Found 25 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 2% 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?
619708841 309 U 353.58409 -48.27215 20.11/17.6 38.0 srclist Yes
619708841 309 U 353.60212 -48.27456 19.92/20.1 77.5 image Yes
List afterglow candidates for other finding charts.
619708683 151 WHITE 353.60722 -48.30090 20.96/18.7 123.9 srclist Yes
619708683 151 WHITE 353.60232 -48.27443 20.83/20.3 78.0 image Yes
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: -48.27456
GRB_ERROR: 0.83
GRB_RA: 353.60212
IMAGE_START_TIME: 13:20:36
MAGNITUDE: 19.92
MAG_ERROR: 0.23
MESSAGE_TYPE: ACK
SOURCE: BAT