image overlap message for exposure 2 of trigger 1069551
uvot_overlap.pl vrs. 2010-12-20b fem started at 210821d02h31m47s713669usUT
The observation of trigger 1069551 started 2021-08-20T17:52:49.5
Examining file ./1069551_g888_uvot_sky_image.fits
The exposure ID is 651174769
The exposure time is 149.857 (seconds)
The filter is U.
The uvot region is centered at (20.6416,4.6103) with a roll angle of 70.9
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 (20.6290,4.6320) with a radius of 3.000 arc min
This is 1.506 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 7.00 sq. arc min or 0.25 of the BAT error circle
The XRT error circle is centered at (20.6396,4.6076) with a radius of 0.042 arc min
This is 0.198 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 1069551
find_uvot_ag.pl vrs. 2020-10-30 fem started at 210821d02h32m01s671332usUT
Observation start time is 2021-08-20T17:52:49.5
Examining file ./1069551_g888_uvot_catalog_image.fits
The exposure ID is 651174769
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is U
There are 9 detected source(s) for 1069551_g888
Aspect correction adds 0.00103 degrees (0.248 sec of time = 3.70 arc sec) to RA
Aspect correction adds -0.00020 degrees (-0.71 arcsec) to Dec
Total aspect correction is 3.77 arcsec
Star catalogs centered at 20.6401 , 4.6081 with radius 2.72 arc min.
n_usno: 48 n_gsc: 0
Bright star catalog has no entries brighter than 12 mag
Mean distance difference (CAT_DELTA) for 1 matched entries is 0.295" for 1069551_g888
Mean and std. dev of mag. difference (MAG_DELTA) are 0.953 and 0.000 for 1069551_g888
Found 8 entries without IDs and 8 entries that are acceptable afterglow candidates for 1069551_g888.
Acceptable entries have no ID, XRT distances < 6.25", 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=20.6290 (01:22:30.96) DEC= 4.6320 (+04:37:55.2)
XRT distances are from RA=20.6396 (01:22:33.51) DEC= 4.6076 (+04:36:27.5)
*** WARNING 88 per cent of entries have no IDs.
-----------------
Entry 0 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.63946 (01:22:33.47) dec=4.60769 (+04:36:27.7) +/- 0.8" mag=18.54+/-0.18
dist=0.6 REFID=6 major=0.9 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
-----------------
Entry 2 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.65659 (01:22:37.58) dec=4.60394 (+04:36:14.2) +/- 1.4" mag=20.49+/-0.44
dist=62.3 REFID=7 major=2.0 minor=1.5 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 141.4 arc sec from the BAT position.
Found 2 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
20.6540 4.6011 13.6 -1 USNO-B1 20.92 20.04 20.43
20.6596 4.6070 15.4 -1 USNO-B1 20.76 19.91 20.29
*** If XRT position is correct, then this is NOT the afterglow
*** unacceptable major profile of 2.0
-----------------
Entry 3 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.65775 (01:22:37.86) dec=4.60988 (+04:36:35.6) +/- 0.9" mag=19.37+/-0.23
dist=65.6 REFID=5 major=1.7 minor=1.5 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 130.3 arc sec from the BAT position.
Found 2 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
20.6596 4.6070 12.2 -1 USNO-B1 20.76 19.91 20.29
20.6607 4.6139 17.9 -1 USNO-B1 21.29 19.92 20.53
*** If XRT position is correct, then this is NOT the afterglow
*** unacceptable major profile of 1.7
-----------------
Entry 4 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.65448 (01:22:37.07) dec=4.59261 (+04:35:33.4) +/- 0.9" mag=19.20+/-0.22
dist=76.0 REFID=9 major=2.3 minor=1.7 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 168.7 arc sec from the BAT position.
Found 1 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
20.6546 4.5888 13.8 -1 USNO-B1 19.30 17.96 18.55
*** If XRT position is correct, then this is NOT the afterglow
*** unacceptable major profile of 2.3
-----------------
Entry 5 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.65902 (01:22:38.16) dec=4.61462 (+04:36:52.6) +/- 0.9" mag=19.22+/-0.22
dist=74.0 REFID=4 major=4.0 minor=2.6 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 124.6 arc sec from the BAT position.
Found 1 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
20.6607 4.6139 6.6 -1 USNO-B1 21.29 19.92 20.53
*** If XRT position is correct, then this is NOT the afterglow
*** unacceptable major profile of 4.0
-----------------
Entry 6 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.65411 (01:22:36.99) dec=4.58847 (+04:35:18.5) +/- 0.9" mag=19.29+/-0.23
dist=86.4 REFID=1 major=3.1 minor=2.2 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 180.8 arc sec from the BAT position.
This source is near the edge of image (0.864)
Found 1 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
20.6546 4.5888 2.1 -1 USNO-B1 19.30 17.96 18.55 *
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 7 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.66054 (01:22:38.53) dec=4.62282 (+04:37:22.2) +/- 1.1" mag=19.91+/-0.30
dist=92.9 REFID=3 major=1.5 minor=1.2 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 117.9 arc sec from the BAT position.
Found 0 entries in star catalog(s) within 20.0" of the candidate.
*** If XRT position is correct, then this is NOT the afterglow
-----------------
Entry 8 in the list of sources is a candidate afterglow for 1069551_g888 with genie
ra=20.66118 (01:22:38.68) dec=4.62778 (+04:37:40.0) +/- 1.2" mag=20.05+/-0.33
dist=106.0 REFID=2 major=0.8 minor=0.8 flag=0
*** The position of this source is inconsistent with the XRT position.
The position is 116.5 arc sec from the BAT position.
This source is near the edge of image (0.926)
Found 0 entries in star catalog(s) within 20.0" of the candidate.
*** If XRT position is correct, then this is NOT the afterglow
Found 0 entries in star catalog(s) within 10" of the XRT position.
List UVOT sources within 10" of the XRT position:
Unmatched source ra=20.63946 (01:22:33.47) dec=4.60769 (+04:36:27.7) +/- 0.8" mag=18.54+/-0.18 dist=0.6 REFID=6 flag=0
There are 10206.618 counts in the bkg source region of 6194.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 1.648 counts/pixel (5-sig UL in 4" is 19.64 mag) for 1069551_g888
There are 177.48010 counts in the src source region of 50.000000 pixels.
Rate in src region with 4 arcsec radius is 3.550 counts/pixel for 1069551_g888
There are 2058.1294 counts in the cand_src_bkg source region of 1249.0000 pixels.
Rate in cand_src_bkg region from 15 to 25 arcsec is 1.648 counts/pixel (5-sig UL in 4" is 19.64 mag) for 1069551_g888
Good candidates have no ID, acceptable profiles,
mag between 9.01 and 20.19, XRT distances < 6.25",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.
SUMMARY: 1 good candidate(s) found.
Region file: 1069551_651174769_210821d02h32m01s671332usUT_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(20.6416,4.6103,45")
fk5;-circle(20.6394602875931,4.6076907959186,6")
Region file: 1069551_651174769_210821d02h32m01s671332usUT_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(20.6394602875931,4.6076907959186,4")
Region file: 1069551_651174769_210821d02h32m01s671332usUT_cand_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(20.6394602875931,4.6076907959186,25")
fk5;-circle(20.6394602875931,4.6076907959186,15")
image paragraph message for exposure 2 of trigger 1069551
------ Start for Possible Stand-alone Circular ----
In response to GRB210820 (Swift/BAT trigger 1069551) at 17:38:00 UT,
---- UVOT paragraph for Joint or Stand-alone Circular ----
UVOT took a finding chart exposure of 150 seconds with the U filter starting
861 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 01:22:33.47 = 20.63946
DEC(J2000) = +04:36:27.7 = 4.60769
with a 90%-confidence error radius of about 0.82 arc sec. This position is 0.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.54 with a 1-sigma error of about 0.18. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.030.
------- notes for trigger 1069551 ------
uvot_gcn_auto.pl vrs. 2020-10-27 fem at 210821d02h32m07s047280usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1069551
-expid=651174769 -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/1069551/
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 651174769.4902 or about 2021:232:17:52:44 UT
Found 460 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 4% of the srclist region. Found 15 sources in
srclist catalog. Found 1 srclist source(s) without IDs. There are 0 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
17.84 mag.
Found 9 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 8 Genie image source(s) without IDs. There are 1 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
20.19 mag. Found 44 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 4% of the Genie image region. The
closest srclist source has ra= 20.6381 dec= 4.5957 mag=16.69 sep=43.28".
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?
651174769 860 U srclist found no candidates.
651174769 860 U 20.63946 4.60769 18.54/20.2 0.6 image Yes
List afterglow candidates for other finding charts.
651174038 129 U 20.63959 4.60783 18.10/18.1 0.7 srclist Yes
651174038 129 U 20.63952 4.60783 17.53/20.5 0.8 image Yes
------- Tokens for Quick GCN -------
CATALOG_TYPE: IMAGE
FILTER: u
GRB_DEC: 4.60769
GRB_ERROR: 0.82
GRB_RA: 20.63946
IMAGE_START_TIME: 17:52:44
MAGNITUDE: 18.54
MAG_ERROR: 0.18
MESSAGE_TYPE: ACK
SOURCE: XRT