image overlap message for exposure 2 of trigger 1048783


uvot_overlap.pl vrs. 2010-12-20b fem started at 210517d09h12m07s207349usUT

The observation of trigger 1048783 started 2021-05-17T05:33:10.3
Examining file ./1048783_g308_uvot_sky_image.fits
The exposure ID is 642922390
The exposure time is 249.935 (seconds)
The filter is U.

The uvot region is centered at (358.1809,-39.0983) with a roll angle of 53.0
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 (358.1740,-39.1050) with a radius of 3.000 arc min
This is 0.515 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 (358.2245,-39.1022) with a radius of 0.037 arc min
This is 2.040 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 0.000 sq. arc min or 0.00 of the XRT error circle



image afterglow message for exposure 2 of trigger 1048783


find_uvot_ag.pl vrs. 2020-10-30 fem started at 210517d09h12m20s511442usUT

Observation start time is 2021-05-17T05:33:10.3
Examining file ./1048783_g308_uvot_sources_image.fits
The exposure ID is 642922390
The exposure is 249.935 sec.
The bin size is 2 pixels
The filter is U
There are 0 detected source(s) for 1048783_g308
*** WARNING -- Aspect solution FAILED.
Results need to be checked by, for example, blinking image with DS9.
Star catalogs centered at 358.1824 , -39.0902 with radius 2.00 arc min.
n_usno: 33 n_gsc: 0
*** WARNING -- XRT position is outside star catalog search region.
Bright star catalog has no entries brighter than 12 mag
Found 0 entries without IDs and 0 entries that are acceptable afterglow candidates for 1048783_g308.
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.
Magnitude criteria will be applied later.
BAT distances are from RA=358.1740 (23:52:41.76) DEC=-39.1050 (-39:06:18.0)
XRT distances are from RA=358.2245 (23:52:53.87) DEC=-39.1022 (-39:06:07.9)

Found 1 entries in star catalog(s) within 20" of the XRT position.
RA Dec Sep. Match USNO/ USNO-B USNO-R USNO-V
GSC GSC-F GSC-J GSC-V
358.2228 -39.1007 7.0 -1 USNO-B1 19.76 19.30 19.51
The closest star is 7.04" away.

List UVOT sources within 20" of the XRT position:
There are 36969.148 counts in the bkg source region of 6320.0000 pixels.
Rate in bkg region from 0 to 45 arcsec is 5.850 counts/pixel (5-sig UL in 4" is 19.51 mag) for 1048783_g308
Do not compute counts in XRT region because position is too far from center.
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 20.06, XRT distances < 5.5",
are > ~(80 - 10*(mag-6))" from any bright star, and have had duplicates removed.

SUMMARY: 0 good candidate(s) found.
Results are questionable because aspect solution FAILED.



Region file: 1048783_642922390_210517d09h12m20s511442usUT_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(358.1809,-39.0983,45")



image paragraph message for exposure 2 of trigger 1048783


IMAGE PROBLEM: no overlap

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

In response to GRB210517 (Swift/BAT trigger 1048783) at 05:28:01 UT,

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

UVOT took a finding chart exposure of 250 seconds with the U filter starting
281 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 0.011.

------- notes for trigger 1048783 ------
uvot_gcn_auto.pl vrs. 2020-10-27 fem at 210517d09h12m24s471138usUT
Command line: /Home/eud/uvot_tdrss/perl/uvot_gcn_auto.pl -trig=1048783
-expid=642922390 -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/1048783/
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 642922390.26926 or about 2021:137:05:33:05 UT

Found 662 stars in largest star catalog for srclist region. The stars will
eliminate afterglows from about 6% of the srclist region. Found 31 sources in
srclist catalog. Found 9 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 0 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 20.06 mag. Found 29 stars in largest star catalog for
Genie image region. The stars will eliminate afterglows from about 5% of the
Genie image region. The XRT position was OUTSIDE the star catalog search
region.

Genie image analysis:
Found 36969.1 counts in the large background region of 6320.0 pixels or a rate
of 5.850 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 19.35 mag. for a
4-arcsec aperture. The closest srclist source has ra= 358.2485 dec= -39.0992
mag=19.62 sep=67.96".

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?
642922390  281 U srclist found no candidates.
642922390  281 U image found no candidates.
List afterglow candidates for other finding charts.
642922178   69 WHITE srclist found no candidates.
642922178   69 WHITE image found no candidates.
642922968  859 WHITE srclist found no candidates.
642922968  859 WHITE image found no candidates.

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

CATALOG_TYPE: SRCLIST
FILTER: u
GRB_DEC: -39.10219
GRB_ERROR: 5.5
GRB_RA: 358.22446
IMAGE_START_TIME: 05:33:05
MAGNITUDE: 18.0
MAG_ERROR: 3.0
MESSAGE_TYPE: NACK
SOURCE: XRT