GRB 220710A

A.A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESTII) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220710A 242493 s after the GECAM/GUANO 
trigger (Tohuvavohu et al., GCN Circ. 32375
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 ).
No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 32385
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 ) is detected 
in the UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. 
Proc. 1358, 373) for the initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white           242493       287404         4429         >22.9

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of 
E(B-V) = 0.030 in the direction of the burst (Schlegel et al. 1998).

A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC
& INAF-OAR), V. D'Elia (SSDC & INAF-OAR), J. D. Gropp (PSU), J.A.
Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester)
and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 220710A, collecting 4.4 ks of Photon
Counting (PC) mode data between T0+242.5 ks and T0+287.4 ks. 

An uncatalogued X-ray source is detected consistent with being within
197 arcsec of the Swift/BAT-GUANO position and is above the 2SXPS
3-sigma upper limit at this position, and is therefore likely the GRB
afterglow.  The position of this source is RA, Dec=221.5668, +20.6576
which is equivalent to:

RA (J2000): 14:46:16.03
Dec(J2000): +20:39:27.3

with an uncertainty of 8.3 arcsec (radius, 90% confidence).  This
position is 83 arcsec from the Swift/BAT-GUANO position.  We cannot
determine at the present time whether the source is fading.

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00021509/Source3.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021509.

This circular is an official product of the Swift-XRT team.

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 220710A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021509

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT-GUANO event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.

Aaron Tohuvavohu (U Toronto), James DeLaunay (UAlabama), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:

Swift/BAT did not localize GRB 220710A onboard (T0:
2022-07-10T03:29:34 UTC, GECAM trig utn220710_032932_GECAMb).

The GECAM notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.

The burst is detected in BAT with a duration of ~25 seconds.
The burst occurred during a Swift slew.
The burst position is found with an image SNR of 20.

The BAT position is
RA, Dec = 221.592, 20.657 deg which is
   RA(J2000)  = 14h 46m 22.08s
   Dec(J2000) =  20d 39��� 25.2���
with an uncertainty of 2 arcmin.

XRT and UVOT follow-up has been requested
Results of follow-up observations will be reported in future circulars.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.