srclist overlap message for exposure 1 of trigger 1000926


uvot_overlap.pl vrs. 2010-12-20b fem started at 201020d13h07m58s259658usUT

The observation of trigger 1000926 started 2020-10-20T05:50:16.2
Examining file ./1000926_g169_uvot_sky_srclist.fits
The exposure ID is 624865816
The exposure time is undefined.
The filter is WHITE.

The uvot region is centered at (261.2401,31.4234) with a roll angle of 241.5
It is square with sides of 8.03 arc min. for an area of 64.51 sq arc min

The BAT error circle is centered at (261.2460,31.4250) with a radius of 3.000 arc min
This is 0.319 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 28.27 sq. arc min or 1.00 of the BAT error circle

The XRT error circle is centered at (261.2283,31.4280) with a radius of 0.030 arc min
This is 0.668 arc min from the center of the uvot region
The area of the XRT error circle is 0.003 sq. arc min
The UVOT/XRT overlap is 0.003 sq. arc min or 1.00 of the XRT error circle



srclist afterglow message for exposure 1 of trigger 1000926


find_uvot_ag.pl vrs. 2017-02-17 fem started at 201020d13h08m01s430548usUT

Observation start time is 2020-10-20T05:50:16.2
Examining file ./1000926_g169_uvot_catalog_srclist.fits
The exposure ID is 624865816
The exposure is 149.857 sec.
The bin size is 2 pixels
The filter is WHITE
There are 79 detected source(s) for 1000926_g169
Aspect correction adds -0.00219 degrees (-0.526 sec of time = -6.74 arc sec) to RA
Aspect correction adds -0.00063 degrees (-2.27 arcsec) to Dec
Total aspect correction is 7.11 arcsec
Star catalogs centered at 261.2401 , 31.4231 with radius 6.30 arc min.
n_usno: 499 n_gsc: 0
*** WARNING -- bright star catalog has 2 entries brighter than 12 mag
The brightest has mag 10.86356
                        RA                      DEC              Mag  Color
bright star  0: 261.26270 (17:25:03.05)  31.46773 (+31:28:03.8) 11.54 USNO-V
bright star  1: 261.13651 (17:24:32.76)  31.47116 (+31:28:16.2) 10.86 USNO-V
Mean distance difference (CAT_DELTA) for 58 matched entries is 0.630" for 1000926_g169
Mean and std. dev of mag. difference (MAG_DELTA) are 1.271 and 0.527 for 1000926_g169
Found 21 entries without IDs and 2 entries that are acceptable afterglow candidates for 1000926_g169.
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.
15 sources matched bright stars.
Magnitude criteria will be applied later.
BAT distances are from RA=261.2460 (17:24:59.04) DEC=31.4250 (+31:25:30.0)
XRT distances are from RA=261.2283 (17:24:54.78) DEC=31.4280 (+31:25:40.9)
*** WARNING 26 per cent of entries have no IDs.

-----------------
Entry 1 in the list of sources is a candidate afterglow for 1000926_g169 with 3x3 stamp
 ra=261.22761 (17:24:54.63) dec=31.42828 (+31:25:41.8) +/- 1.1" mag=18.67+/-0.35
 dist=2.2 REFID=30
 src: 1 distr. of nearby unmatched sources: 0 0 0 0 0 
Found 1 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 
  261.2270  31.4330  16.9    -1 USNO-B1  21.25  20.07  20.59
##### This source remains a candidate #####
    It has no entries within 4" or brighter than 13 mag

-----------------
Entry 4 in the list of sources is a candidate afterglow for 1000926_g169 with 3x3 stamp
 ra=261.25356 (17:25:00.85) dec=31.44567 (+31:26:44.4) +/- 1.1" mag=19.78+/-0.35
 dist=100.4 REFID=49
*** The position of this source is inconsistent with the XRT position.
    The position is 78.0 arc sec from the BAT position.
 src: 4 distr. of nearby unmatched sources: 1 0 0 0 0 
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 
  261.2537  31.4433   8.5    -1 USNO-B1  15.78  15.16  15.44
  261.2536  31.4448   3.0    -1 USNO-B1  17.71  17.29  17.48 *
Due to star catalog entries marked with *, this is probably NOT the afterglow
    These entries are within 4" or brighter than 13 mag

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=261.22761 (17:24:54.63) dec=31.42828 (+31:25:41.8) +/- 1.1" mag=18.67+/-0.35 dist=2.2 REFID=30

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

SUMMARY: 1 good candidate(s) found.



srclist paragraph message for exposure 1 of trigger 1000926



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

In response to GRB201020 (Swift/BAT trigger 1000926) at 05:47:26 UT,

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

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 144 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 17:24:54.67 = 261.22779
DEC(J2000) = +31:25:42.0 = 31.42834
with a 90%-confidence error radius of about 0.62 arc sec. This position is 1.8
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.14 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04.

------- notes for trigger 1000926 ------
uvot_gcn_auto.pl vrs. 2016-09-07 fem at 201020d13h08m16s528852usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1000926
-expid=624865816 -meonly -msg_srclist
Results from standard processing of UVOT TDRSS data for this trigger should be
available at
http://heasarc.gsfc.nasa.gov/docs/swift/uvot_tdrss/1000926/
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 624865816.20964 or about 2020:294:05:50:11 UT

Found 495 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 8% of the srclist region. Found 79 sources in
srclist catalog. Found 21 srclist source(s) without IDs. There are 1 good
candidate(s) in the srclist catalog. Good candidates must be brighter than
19.22 mag.

Found 11 source(s) in Genie image catalog. 1 source(s) are within 10.0" of the
xrt position. Found 2 Genie image source(s) without IDs. There are 1 good
candidate(s) in the Genie image catalog. Good candidates must be brighter than
20.85 mag. Found 65 stars in largest star catalog for Genie image region. The
stars will eliminate afterglows from about 6% 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?
624865816  144 WHITE 261.22761	31.42828  18.67/19.2	2.2  srclist  Yes
624865816  144 WHITE 261.22779	31.42834  18.14/20.9	1.8  image    Yes
List afterglow candidates for other finding charts.
624865974  302 U srclist found no candidates.
624865974  302 U     261.22771	31.42832  19.95/20.7	2.0  image    Yes

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

CATALOG_TYPE: IMAGE
FILTER: white
GRB_DEC: 31.42834
GRB_ERROR: 0.62
GRB_RA: 261.22779
IMAGE_START_TIME: 05:50:11
MAGNITUDE: 18.14
MAG_ERROR: 0.15
MESSAGE_TYPE: ACK
SOURCE: XRT