GRB 240712A

C. Salvaggio (INAF-OAB), N. P. M. Kuin (UCL-MSSL),
D. M. Palmer (LANL), T. Sbarrato (INAF-OAB) and
B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 03:27:12 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240712A (trigger=1242223).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 122.369, -37.077 which is 
   RA(J2000) = 08h 09m 29s
   Dec(J2000) = -37d 04' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve before T+8s after the
trigger is unavailable due to a telemetry outage.  The burst triggered
on the 8s timescale indicating that it is a long burst, but
no other duration information is presently available. 

The XRT began observing the field at 03:29:47 UT, 155 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 122.3378, -37.0923 which is equivalent to:
  RA(hh mm ss.s) = 8h09m21.08s
Dec(dd mm ss.s) = -37:05:32.21
with an uncertainty of 6.4 arcseconds (radius, 90% containment). This
location is 105 arcseconds from the BAT onboard position, within the BAT
error circle. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 140 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 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the large, but uncertain, extinction expected. 

Burst Advocate for this burst is C. Salvaggio (chiara.salvaggio AT inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)

N. P. M. Kuin (UCL-MSSL) and C. Salvaggio (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 240712A
141 s after the BAT trigger (Salvaggio et al., GCN Circ. 36851
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 ).
No optical afterglow consistent with the XRT position in GCN Circ
36851
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  is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           141          290          147         >20.2
u_FC               299          549          246         >19.9
white              141         1550          392         >21.0
v                  629         5288          179         >19.0
b                  555         1525           97         >20.0
u                  299         1500          324         >20.3
w1                 678         1476           97         >19.2
m2                 653         1451           97         >18.7
w2                 604         5200          313         >19.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.996 in the direction of the burst
(Schlegel et al. 1998).

S. Chastain (UNM), J. K. Leung (U. Toronto/HUJI), G. E. Anderson (Curtin University),
A. Gulati (U. Sydney), L. Rhodes (U. Oxford),
A. J. van der Horst (GWU) on behalf of the PanRadio GRB collaboration

The Australia Telescope Compact Array (ATCA) performed observations
of the long GRB 240712A detected by Swift-BAT (Salvaggio et al., GCN 36851
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 ),
at 5.5, 9, 16.7 and 21.2 GHz as part of the Large ATCA "PanRadio GRB"
follow-up programme C3542 (PI. Anderson). ATCA start observing on
2024-07-12 at 4:08 UT (~2 hours post-burst) and continued to observe
until 9:21 UT on 2024-07-12. In our preliminary analysis, we find
no radio source coincident with the Swift XRT uncataloged source
(Salvaggio et al., GCN 36851
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 ) with 3 sigma upper limits of
72, 63, 192 and 717 microJy/beam at 5.5, 9.0, 16.7 and 21.2 GHz, respectively.

We thank the CSIRO Space and Astronomy staff for supporting these
observations. We acknowledge the Gomeroi people as the traditional
owners of the Observatory site. The Australia Telescope Compact Array is
part of the Australia Telescope National Facility
(https://ror.org/05qajvd42) which is funded by the Australian Government
for operation as a National Facility managed by CSIRO.

P. A. Evans (U. Leicester), K.L. Page (U. Leicester), C. Salvaggio
(INAF-OAB), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) reports
on behalf of the Swift-XRT team:

We have analysed 1.7 ks of XRT data for the Swift/BAT-detected burst
GRB 240712A, from 152 s to 5.3 ks after the  Swift/BAT trigger. The
data are entirely in Photon Counting (PC) mode. Using 1421 s of PC mode
data and 2 UVOT images, we find an enhanced XRT position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 122.33591, -37.08814 which is equivalent to:

RA (J2000): 08h 09m 20.62s
Dec(J2000): -37d 05' 17.3"

with an uncertainty of 3.2 arcsec (radius, 90% confidence). This
position is 103 arcsec from the Swift/BAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.9 (+/-0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.5 (+1.1, -1.0). The
best-fitting absorption column is  2.6 (+2.5, -1.7) x 10^22 cm^-2,
consistent with the Galactic value of 8.9 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 9.0 x 10^-11 (1.4 x
10^-10) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     2.6 (+2.5, -1.7) x 10^22 cm^-2
Galactic foreground: 8.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.5 (+1.1, -1.0)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01242223.

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

T. Parsotan (GSFC), S. D. Barthelmy (GSFC),
R. Gupta (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), M. J. Moss (GSFC),
D. M. Palmer (LANL), D. Sadaula (GSFC/UMBC),
T. Sakamoto (AGU)(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240712A (trigger #1242223)
(Salvaggio et al., GCN Circ. 36851
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 ). The BAT ground-calculated position is
    RA, Dec = 122.385, -37.093 deg which is
       RA(J2000)  =  08h 09m 32.3s
       Dec(J2000) = -37d 05' 36.3"
with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 93%.

The BAT light curve shows a complex structure with a duration of ~ 20 sec.
T90 (15-350 keV) is 16.45 +- 4.89 sec (estimated error including systematics).

The time-averaged spectrum from T-4.68 to T+12.59 sec is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.29 +- 0.30.
The fluence in the 15-150 keV band is 2.7 +- 0.5 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+1.24 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1242223