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GRB 250702F

GCN Circular 41082

Subject
GRB 250702F: Swift-BAT refined analysis
Date
2025-07-13T21:00:20Z (3 months ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
Web form
M. J. Moss (GSFC), S. D. Barthelmy (GSFC), R. Gupta (GSFC),
N. J. Klingler (GSFC/UMBC/CRESSTII) H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 250702F (trigger #1329888)
(Klingler, et al., GCN Circ. 40894).  The BAT ground-calculated position is
RA, Dec = 212.942, 16.739 deg which is
   RA(J2000)  =  14h 11m 46.1s
   Dec(J2000) = +16d 44' 20.6"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.

The mask-weighted light curve shows a complex structure that starts at
~T-3 s, peaks at ~T+38 s, and ends at ~T+80 s.
T90 (15-350 keV) is 63.7 +- 12.5 sec (estimated error including systematics).

The time-averaged spectrum from T-29.13 to T+76.44 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.49 +- 0.06.  The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+37.35 sec in the 15-150 keV band
is 5.1 +- 0.3 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/1329888

GCN Circular 41023

Subject
GRB 250702F: radio detection with the VLA
Date
2025-07-08T12:10:37Z (3 months ago)
From
Stefano Giarratana at INAF-OAB <s.giarratana@ira.inaf.it>
Via
email
S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA),
G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),
N. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB),
L. Nava (INAF-OAB)

At 02:54:00 UT on 2025 July 6 (T_mid = 3.27 days post-burst)
the Karl G. Jansky VLA observed the field of GRB 250702F
(Fermi GBM team, GCN 40892; Klingler et al., GCN 40894;
Frederiks et al., GCN 40948) in three bands, with central
frequencies of 6, 10 and 15 GHz.

The standard 3C286 was used as bandpass and flux density
calibrator, while J1415+1320 was used as phase calibrator.

From a preliminary analysis, an unresolved radio source
is detected at a position (J2000):

RA: 14:11:44.641 +- 0.004
Dec: +16:44:54.68 +- 0.06

consistent with the X-ray (Goad et al., GCN 40902;
Liang et al., GCN 40967) and optical (Klingler et al.,
GCN 40894; Jelinek et al., GCN 40895; Kumar et al., GCN 40896;
Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900;
de Ugarte Postigo et al., GCN 40901; Angulo et al., GCN 40907;
Becerra et al., GCN 40911; Brivio et al., GCN 40913; An et al.,
GCN 40916; Dutton et al., GCN 40921; Odeh et al., GCN 40925;
Moretti et al., GCN 40926; Siegel et al., GCN 40933; Ma et al.,
GCN 40936; Vinko et al., GCN 40939; Mohan et al., GCN 40946;
Ciabattari et al., GCN 40968; Broens et al., GCN 40969;
Calapai et al., GCN 40973; Antier et al., GCN 41011) position
of the transient.

The preliminary analysis yields the following results:

================================================================
T_mid	Freq	Peak	r.m.s.	Beam		PA
[days]	[GHz]	[uJy/b]	[uJy/b]	[arcsec^2]	[deg]
================================================================
3.27	6	158	7	3.31x3.03	22
3.27	10	127	6	2.09x1.95	31
3.27	15	141	7	1.39x1.26	1
================================================================

We would like to thank the staff of the VLA for approving, executing,
and processing the observations.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc.

These observations were carried out as part of project SF171028,
approved in the framework of the Fermi - NRAO joint program agreement.

GCN Circular 41011

Subject
GRB 250702F: GRANDMA observations
Date
2025-07-07T16:38:26Z (3 months ago)
From
Sarah Antier at OCA <sarah.antier@oca.eu>
Via
Web form
S. Antier (OCA/IJCLAB), S. Karpov (FZU),  E. de Bruin (UMN), N. Kochiashivili (AbAO), M. Lamoureux (Uliege), T. Du Laz (Caltech), A. Klotz (IRAP), C. Limonta (OCA) on behalf of GRANDMA:

We observed the field of GRB 250702F (Fermi GBM team, GCN 40892; Klingler et al., GCN 40894) with TAROT and Kilonova catcher (GCN 40969), 1.72 min post T0 and obtained optical counterpart detection.

All our measurements are made public and can be downloaded in order to support the Swift and Fermi/GBM GRB science: https://skyportal-icare.ijclab.in2p3.fr/public/sources/GRB-250702_210643/version/9d4e549b1a3ed2535aae7b1392c94c2c

All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2025). Images obtained with the sloan filters were calibrated using the PanSTARRS DR1 catalog. Images obtained with the Johnson-cousins filters were calibrated using the GAIA DR3 synphot catalog.

We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023).

Our observations are consistent with other already reported (see the Skyportal page) Jelinek et al. (GCN 40895); Kumar et al. (GCN 40896); Lipunov et al. (GCN 40898); Martin-Carrillo et al. (GCN 40900); Angulo et al. (GCN 40907); Becerra et al. (GCN 40911); Brivio et al. (GCN 40913); An et al. (GCN 40916); Dutton et al. (GCN 40921); Odeh et al. (GCN 40925); Moretti et al. (GCN 40926); Siegel et al. (GCN 40933); Ma et al. (GCN 40936); Vinko et al. (GCN 40939); Mohan et al. (GCN 40946); Ciabattari et al. (GCN 40968).


GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
Skyportal/ICARE is supported by ACME.

GCN Circular 40973

Subject
GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
Date
2025-07-05T11:42:59Z (3 months ago)
From
Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, Messina, Italy <giovannicalapai@tiscali.it>
Via
Web form
Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, (Messina) Italy 
Member of: GRB/UAI Gamma Ray Burst Section of Unione Astrofili Italiani. 

Report:

We observed the field of GRB 250702F detected by Swift/BAT (Klingler et al., GCN 40894) and Fermi/GBM (Fermi GBM Team, GCN 40892) with the 11 inches Schmidt-Cassegrain (Celestron 11) telescope F/D=6,3. 
  
The observations were started at 2025-07-02 21:32:30 UT (approximately 0.43 hours after burst) stacking two consecutive sets of unfiltered CCD image. The observations were carried out with clear skies and good visibility conditions.

The OT was detected at the following position:

RA    (J2000.0)  14h 11m 44.68s   
Decl. (J2000.0) +16° 44' 55.0" 	 

Photometry was obtained using nearby PanSTARRS stars as follows: 

Observation    Mid-Time    T-T0 (hr)      Exposure        Filter      Mag.     Mag. err.
2025-07-02   22:03:02 UT    0.94           60x60s           CR       17.13     +/-0.02
2025-07-02   23:05:09 UT    1.97           60x60s           CR       18.07     +/-0.05

Magnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations. 
No correction for galactic dust extinction was applied.

Our observations are consistent with other already reported Jelinek et al. (GCN 40895); Kumar et al. (GCN 40896); Lipunov et al. (GCN 40898); Martin-Carrillo et al. (GCN 40900); Angulo et al. (GCN 40907); Becerra et al. (GCN 40911); Brivio et al. (GCN 40913); An et al. (GCN 40916); Dutton et al. (GCN 40921); Odeh et al. (GCN 40925); Moretti et al. (GCN 40926); Siegel et al. (GCN 40933); Ma et al. (GCN 40936); Vinko et al. (GCN 40939); Mohan et al. (GCN 40946); Ciabattari et al. (GCN 40968); Broens et al. (GCN 40969).

The message may be cited.

GCN Circular 40969

Subject
GRB 250702F: Kilonova-Catcher optical afterglow detection
Date
2025-07-05T07:49:37Z (3 months ago)
From
Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com>
Via
Web form
E. Broens,  M. Freeberg, R. Hellot (KNC), D. Turpin (CEA-Saclay/Irfu), C. Andrade(UMN), M. Pillas (ULiege), M. Tanasan (NARIT), S. Antier (OCA/IJCLAB) on behalf of the GRANDMA/Kilonova-Catcher collaboration:

We observed the field of GRB 250702F (Fermi GBM team, GCN 40892; Klingler et al., GCN 40894) with the GRANDMA citizen science project Kilonova-catcher (KNC). Our observations were performed with the T-BRO telescope operated by E. Broens and the CDK17 telescope located at AITP San Pedro Chile Observatory operated by R. Hellot, the iTelescope T72 and TEC180FL telescope operated by M. Freeberg and the 14SC telescope operated by M Odeh. Our observations started at TGRB+1.8hr. 

In our stacked frames, subtracted from the PanSTARRS DR2 template image, we detect the optical counterpart reported by Swift/UVOT (Klingler et al., GCN 40894, Siegel et al., GCN 40933) and further confirmed by many other teams (Jelinek et al.,GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900; de Ugarte Postigo et al., GCN 40901; Angulo et al., GCN 40907; Becerra et al., GCN 40911; Brivio et al., GCN 40913; An et al., GCN 40916; Dutton et al., GCN 40921; Odeh et al., GCN 40925; Moretti et al., GCN 40926; Ma et al., GCN 40936; Vinko et al., GCN 40939; Mohan et al., GCN 40946)

We report some of our first image follow-up results in the table below: 

+---------------+-----------+------------+---------------+------------|
| Tmid-TGRB (hr)| Exp (s)   | Filter     | Magnitude     | Instrument |
+===============+===========+============+===============+============+
| 1.9           | 5 x 180s  | R (Vega)   | 18.11 +/- 0.08 | T-BRO     | 
| 2.8           | 300s      | sdssr (AB) | 18.45 +/- 0.07 | CDK17-AITP| 
| 3.8           | 300s      | sdssg (AB) | 19.01 +/- 0.08 | CDK17-AITP| 
| 3.2           | 10 x 180s | R (Vega)   | 18.56 +/- 0.06 | iT72      | 
| 7.1           | 16 x 180s | sdssr (AB) | 19.54 +/- 0.15 | TEC180FL  | 
+---------------+-----------+------------+----------------+-----------+

All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained with the sloan filters were calibrated using the PanSTARRS DR1 catalog. Images obtained with the Johnson-cousins filters were calibrated using the GAIA DR3 synphot catalog. 

We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023). 

GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).

GCN Circular 40968

Subject
GRB 250702F: Monte Agliale Observatory optical observations
Date
2025-07-05T06:56:14Z (3 months ago)
From
Fabrizio Ciabattari at Monte Agliale Observatory <fabciaba@alice.it>
Via
Web form
F. Ciabattari, S. Donati, G. Fornaciari, S. Guidotti, E. Mazzoni, M. Rossi, R. Simonetti,  R. Bernacchi, F. Biagini, R. Gemignani, M. Giovannini and G. Petroni (Monte Agliale Observatory, Borgo a Mozzano, Italy) report:

We observed the field of GRB 250702F (Klingler et al. GCN 40894) with the automatic 0.5m f/4.6 Newtonian telescope + SBIG ST10 camera at Monte Agliale Observatory (Borgo a Mozzano, Italy, MPC code 159).
The observations started at 2025-07-02 21:08:57.6 UT (135 seconds after the burst) and were automatically triggered by notices received via the kafka platform.
A series of 15 unfiltered images of 30 seconds each was taken and we detect the optical counterpart reported by Klingler et al. (GCN Circ. 40894) and many other observers. As described by Jelinek et al. (GCN Circ. 40895) the light curve peaked at unfiltered magnitude ~15 and showed a slow decay in the following minutes with a decrease of approximately 0.5 mag in 6 minutes. 

A Differential Photometric Analysis of this GRB is available at:
https://www.oama.it/archivio/GRB250702F/grb_250702f.htm

GCN Circular 40967

Subject
GRB250702F: afterglow detected by joint EP-ZTF shadowing program
Date
2025-07-05T06:48:13Z (3 months ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
R. D. Liang, D.Y. Li, H. Q. Cheng, Z. X. Ling (NAO, CAS), Y. J. Zhang (THU), C. Zhou (HUST), G. Y. Zhao (SYSU), A. Li (BNU), Y. H. Cheng (SWIFAR, YNU), C. C. Jin, and W. M. Yuan (NAO, CAS), Robert Stein (UMD), Tomas Ahumada (Caltech), Mansi Kasliwal(Caltech), Theophile du Laz (Caltech), and Lin Yan (Caltech) on behalf of the Einstein Probe (EP) team and the Zwicky Transient Facility Partnership:
 
We report on the joint identification of the afterglow of GRB 250702F (Swift/BAT detection,  GCN 40894; Fermi/GBM detection, GCN 40892) by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission and ZTF through the EP-ZTF shadowing program (Ahumada et al., GCN 39791). The EP-WXT observation started at 2025-07-02 21:41:26 (UTC), about 2ks after Swift/BAT detection. The WXT position of the source is R.A. = 212.899 deg, DEC = 16.74 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic), which is consistent with the optical counterpart (ZTF25aazgntl/AT2025qdw, TNS#183358; Klingler et al., GCN 40894; Jelinek et al., GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al. GCN 40900; de Ugarte Postigo et al. GCN 40901; Angulo et al. GCN 40907; Becerra et al. GCN 40911; Brivio et al. GCN 40913; An et al. GCN 40916; Odeh et al. GCN 40925; Moretti et al. GCN 40926) and the X-ray counterpart (Swift/XRT team, GCN 40902, GCN 40928).
 
The WXT spectrum can be fitted with an absorbed power law model with fixed column density of 1.34e20 cm^-2, a photon index of 2.06+/-0.71, and an unabsorbed 0.5-4 keV flux of (5.13+/-0.81)e-11 erg/s/cm^2, which is consistent with Swift/XRT analysis (Swift/XRT team, GCN 40928).
 
The contact transient advocate of this source is Runduo Liang (liangrd@bao.ac.cn). Please contact him for coordination of multi-wavelength follow-up observations and access to EP-WXT data.  
 
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).

GCN Circular 40948

Subject
Konus-Wind detection of GRB 250702F
Date
2025-07-04T13:22:06Z (3 months ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
Via
email
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 250702F (Fermi-GBM detection:
The Fermi GBM team, GCN 40892; Mukherjee & Meegan, GCN 40927;
Swift detection: Klingler et al., GCN 40894)
triggered Konus-Wind (KW) at T0=76042.205 s UT (21:07:22.205).

The burst shows multiple emission pulses and has a total duration of ~46 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB250702_T76042/

As observed by Konus-Wind, the burst had
a fluence of (1.60 ± 0.25)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 0.512 s,
of (5.02 ± 1.15)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

Modeling the time-integrated spectrum of the burst
by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.47 (-0.10, + 0.10) and Ep = 480(-130,+250) keV.

The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range by a GRB (Band) function
with the following model parameters:
the low-energy photon index alpha = -1.22 (-0.12,+0.17),
the high energy photon index beta = -2.20 (-7.8,+0.29),
the peak energy Ep = 505 (-155,+326) keV,
chi2 = 85/94 dof.

Assuming the redshift z=1.520 (de Ugarte Postigo et al., GCN 40896)
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the burst isotropic energy release E_iso to (9.9 ± 1.5)x10^52 erg,
the isotropic peak luminosity L_iso to (7.8 ± 1.8)x10^52 erg/s, and
the rest-frame peak spectral energy Ep,z to ~1250 keV.
With the obtained estimates, GRB 250702F is consistent with 90% prediction bands
of both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW GRBs
with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021),
see http://www.ioffe.ru/LEA/GRBs/GRB250702_T76042/GRB250702F_rest_frame.pdf

All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.

GCN Circular 40946

Subject
GRB 250702F: GROWTH-India Telescope optical observations
Date
2025-07-04T12:52:24Z (3 months ago)
From
V. Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>
Via
Web form

T. Mohan, V. Swain, A. Salgundi, A.P. Saikia, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:

We observed the field of GRB 250702F (Klingler et al., GCN 40894

Loading...
 
 
, Fermi GBM, GCN 40892), with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2025-07-03 16:43:24 UT, i.e., 19.6 hours after the Fermi/Swift trigger. We obtained multiple exposures in r' and i' filters. We detected the optical afterglow in our stacked image of r' filter at position reported by Swift UVOT (Siegel et al., GCN 40933). The photometry results are as follows:

MJD (mid)Filtert-t0 (in hours)Total Exposure Time (sec)Magnitude (AB)
60859.721180r'20.26 x 30020.57 +/- 0.09
60859.727245i'20.343 x 300>19.4

The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.

Our magnitude is consistent with other optical observations (Jeliken et al., GCN 40895

Loading...
 
 
, Kumar et al., GCN 40896, Lipunov et al., GCN 40899, Carrillo et al., GCN 40900, Angulo et al., GCN 40907, Becerra et al., GCN 40911, Brivio et al., GCN 40913, An et al., GCN 40916, Dutton et al., GCN 40921, Odeh et al., GCN 40925, Moretti et al., GCN 40926, Ma et al., GCN 40936, Vinko et al., GCN 40939).

The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.

GCN Circular 40939

Subject
GRB 250702F: optical photometry from Konkoly
Date
2025-07-04T08:55:20Z (3 months ago)
From
Jozsef Vinko at Konkoly Observator <vinko@konkoly.hu>
Via
email
GRB 250702F: optical photometry from Konkoly 

J. Vinko, K. Sarneczky, A. Horti-David, R. Konyves-Toth, Zs. Bora, L. Kriskovics, A. Pal, R. Szakats 
(Konkoly Observatory, Hungary) 

We report detection and photometry of the optical afterglow of GRB 250702F (Fermi GRB team, GCN 40892; Klinger et al. GCN 40894) taken with the RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory, Hungary. The observations started on 2025-07-03 21:15:51 UT, 24.15 hours after the trigger. 5 sets of 300 sec frames were collected through Sloan g', r'- and i' bands. 

The optical afterglow (Klingler et al., GCN 40894; Jelinek et al., GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900; de Ugarte Postigo et al., GCN 40901; Angulo et al., GCN 40907; Becerra et al., GCN 40911; Brivio et al., GCN 40913; An et al., GCN 40916; Dutton et al., GCN 40921; Odeh et al., GCN 40925; Moretti et al., GCN 40926; Siegel et al., GCN 40933; Ma et al. GCN 40936) was detected on the stacked frames with the following magnitudes, calibrated via nearby PS1 stars: 

Date UT-middle t-T0(days) Exp(s) g'(AB) r'(AB) i'(AB) 
2025-07-03 21:23:27.12 1.006 5x300 21.06 (0.26) 20.77 (0.18) 20.06 (0.15) 

The magnitudes above are not corrected for galactic extinction.

GCN Circular 40936

Subject
GRB 250702F: SVOM/VT optical observation
Date
2025-07-04T05:57:52Z (3 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Y.N. Ma, L. P. Xin, Y. L. Qiu, C. Wu, H. L. Li, Z. H. Yao, X. H. Han, Y. Xu, J. Wang, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA), Y. H. Cheng(YNU), J. X. Cao(GXU) report on behalf of the SVOM/VT team 

SVOM/VT performed a Target of Opportunity observation of GRB 250702F detected by Swift-BAT（Klingler et al., GCN 40894） and Fermi-GBM (Fermi GBM Team, GCN 40892). The observation began at 2025-07-03T15:11:40 UTC, 18.08 hours after the trigger, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously.

The optical afterglow (Klingler et al., GCN 40894; Jelinek et al., GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900; de Ugarte Postigo et al., GCN 40901; Angulo et al., GCN 40907; Becerra et al., GCN 40911; Brivio et al., GCN 40913; An et al., GCN 40916; Dutton et al., GCN 40921; Odeh et al., GCN 40925; Moretti et al., GCN 40926; Siegel et al., GCN 40933) is detected using VT X-band data. The magnitudes in both channels are: 
       start time (UT) | exposure time (s) | band | mag (AB) | mag err 
-----------------------|-------------------|------|----------|-------- 
2025-07-03T17:25:09.50 |        30*70      | VT_B |   20.72  |  0.04 
2025-07-03T17:25:09.50 |        30*70      | VT_R |   20.11  |  0.04 

Our photometry was not corrected for Galactic extinction.

The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Centre for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS.

GCN Circular 40933

Subject
GRB 250702F: Swift/UVOT Detection
Date
2025-07-04T05:01:32Z (3 months ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
Via
Web form
M. H. Siegel (PSU) and N. J. Klingler (GSFC/UMBC/CRESSTII)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 250702F 97 s after the BAT trigger (Klingler et al., GCN Circ. 40894). A source consistent with the XRT position (Goad et al., GCN Circ. 40902) is detected in the initial UVOT exposures. The source is detected in all filters except for uvw2 and only marginally in uvm2, which would be consistent with the redshift reported by de Ugarte Postigo et al. (GCN Circ. 40901).

The preliminary UVOT position is:
    RA  (J2000) =  14:11:44.66 = 212.93610 (deg.)
    Dec (J2000) = +16:44:55.1  =  16.74863 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

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

white               97          247          147         15.86 +/- 0.02
v                 5904         6104          197         18.39 +/- 0.14
b                 3878         4077          197         18.42 +/- 0.09
u                  309          515          202         15.04 +/- 0.03
m2                9609        10131          514         19.53 +/- 0.24
w2                5699         5899          197        >19.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.017 in the direction of the burst
(Schlegel et al. 1998).

GCN Circular 40928

Subject
GRB 250702F: Swift-XRT refined Analysis
Date
2025-07-04T00:28:33Z (3 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
J.P. Osborne (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti
(INAF-OAB), C. Salvaggio (INAF-OAB), D.N. Burrows (PSU), M.A. Williams
(PSU), S. Dichiara (PSU), K.L. Page (U. Leicester) and P.A. Evans
report on behalf of the Swift-XRT team:

We have analysed 5.2 ks of XRT data for GRB 250702F, from 94 s to 94.1
ks after the   trigger. The data comprise 420 s in Windowed Timing (WT)
mode with the remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+3.9 ks) can be modelled with a
power-law decay with a decay index of alpha=1.01 (+/-0.06).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 2.016 (+/-0.029). The
best-fitting absorption column is  3.5 (+/-0.5) x 10^21 cm^-2, at a
redshift of 1.52, in addition to the Galactic value of 1.3 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 1.95 (+/-0.13) and a best-fitting absorption column of 2.1 (+2.1,
-1.9) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV
flux conversion factor deduced from this spectrum  is 3.3 x 10^-11 (3.7
x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.3 x 10^20 cm^-2
Intrinsic column:    2.1 (+2.1, -1.9) x 10^21 cm^-2 at z=1.52
Photon index:	     1.95 (+/-0.13)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01329888.

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

GCN Circular 40927

Subject
GRB 250702F: Fermi GBM Observation
Date
2025-07-04T00:25:21Z (3 months ago)
From
oindabimukherjee@gmail.com
Via
Web form
O. Mukherjee (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 21:06:43.10 UT on 02 July 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250702F (trigger 773183208/250702880).
which was also detected by Swift BAT (N. J. Klingler et al. 2025), GOTO (A. Kumar et al. 2025, GCN 40896), AKO (Mohammad Odeh et al. 2025, GCN 40925).
A spectroscopic redshift of z = 1.52 was reported by GTC/OSIRIS (A. de Ugarte Postigo et al. 2025, GCN 40901) 

The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight is 43 degrees.

The GBM light curve consists of multiple pulses with a duration (T90)
of about 54 s (50-300 keV). The time-averaged spectrum
from T0-29 to T0+48 s is best fit by
a band function with alpha = -1.34 +/- 0.06 and beta = -1.78 +/- 0.09 and the cutoff energy,
parameterized as Epeak, is 403 +/- 148 keV.

The event fluence (10-1000 keV) in this time interval is
(1.45 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+38 s in the 10-1000 keV band is 9.7 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

GCN Circular 40926

Subject
GRB 250702F: Leavitt Observatory optical observations
Date
2025-07-03T18:42:20Z (3 months ago)
From
leavittob@gmail.com
Via
Web form
L. Moretti, E. Pavoni (Leavitt Observatory, Italy)

Members of:
GRB/UAI - Gamma Ray Burst Section of Unione Astrofili Italiani
ATA - Associazione Tuscolana di Astronomia

In a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), report:

We observed the field of GRB 250702F detected by Fermi-GBM (GCN 40892) and Swift/UVOT (Klingler et al., GCN 40894), using our Ritchey-Chrétien telescope (D=250 mm, F/D=8).

The observations began approximately 0.5 hours after the trigger, ending at 2025-07-02T23:59:57 UT, stacking a set of CCD images of 180 seconds each, with good weather conditions. All images were processed by a single data processing pipeline based on astropy package (Astropy Collaboration et al., 2022ApJ...935..167A).

The optical afterglow reported by Jelinek et al. (GCN 40895), Kumar et al. (GCN 40896), Lipunov et al. (GCN 40899), Martin-Carrillo et al. (GCN 40900), de Ugarte Postigo et al. (GCN 40901), Angulo et al. (GCN 40907), Becerra et al. (GCN 40911), Brivio et al. (GCN 40913), An et al. (GCN 40916), Dutton et al. (GCN 40921) was clearly detected at the following coordinates:

RA (J2000) =  14:11:44.65
Dec(J2000) = +16:44:54.59


with the following photometry: 

Date UT at mid-exposure         Exposure        Filter      Mag.   Mag. err.
2025-07-02   21:38:43 UT        4x180s           CR       17.33    +/-0.21
2025-07-02   21:52:08 UT        4x180s           CR       17.72    +/-0.21
2025-07-02   22:05:47 UT        5x180s           CR       17.96    +/-0.21

2025-07-02   22:19:44 UT        4x180s           R        18.13    +/-0.25
2025-07-02   22:31:52 UT        4x180s           R        17.80    +/-0.21
2025-07-02   22:44:01 UT        4x180s           R        18.02    +/-0.25
2025-07-02   22:59:11 UT        5x180s           R        18.30    +/-0.21
2025-07-02   23:17:29 UT        4x180s           R        18.80    +/-0.25
2025-07-02   23:29:38 UT        4x180s           R        19.00    +/-0.25
2025-07-02   23:47:50 UT        8x180s           R        19.30    +/-0.21


CR magnitude is unfiltered with R zero point.
R is Rc filter in Johnson-Cousins system.

Magnitude was calibrated with the Pan-STARRS cat. and are derived using Lupton (2005) equations. Not corrected for galactic dust extinction.

This message may be cited.


Reference:
https://leavittobservatory.altervista.org

GCN Circular 40925

Subject
GRB 250702F: AKO Optical Afterglow Detection
Date
2025-07-03T18:36:05Z (3 months ago)
From
Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>
Via
email
Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International
Astronomical Center in Abu Dhabi, UAE), and Nidhal Guessoum (American
University of Sharjah, UAE), report:

We observed the field of GRB 250702F detected by Swift/BAT (Klingler et al.,
GCN 40894) and Fermi/GBM (Fermi GBM Team, GCN 40892), using our 0.36m f/7.7
robotic telescope. The observation session began on 03 July 2025 at 17:04
UT, with a midpoint at 17:42 UT, approximately 20.6 hours after the trigger.

 

We obtained multiple 180-second exposures using the Ic filter. The optical
afterglow was marginally detected at:

R.A. (J2000): 14:11:44.6  

Dec. (J2000): +16:44:55

 

Our detection is consistent with the results of (Jelinek et al., GCN 40895;
Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al.,
GCN 40900; Angulo et al., GCN 40907; Becerra et al., GCN 40911; Brivio et
al., GCN 40913; An et al., GCN 40916; Dutton et al., GCN 40921).

 

The following observation was calculated using the Atlas catalogue as a
reference:

----------------------------------------------------------------------------
-

ObsTime (mid), Exposure (sec), Filter, Mag

----------------------------------------------------------------------------
-

2025-07-03T17:42:28Z, 26 x 180s (stacked), Ic, 19.5 +/- 0.4

----------------------------------------------------------------------------
-

The magnitude is not corrected for galactic extinction.

GCN Circular 40921

Subject
GRB 250702F: Skynet Optical Observations
Date
2025-07-03T16:24:13Z (3 months ago)
From
Dylan Dutton at UNC Chapel Hill <ddutton59@gmail.com>
Via
Web form
Dylan Dutton, Daniel Reichart, Joshua Haislip, Vladimir Kouprianov, Staszek Zola, Tyler Linder, and Jonathan Keohane report on behalf of the Skynet Robotic Telescope Network at the University of North Carolina at Chapel Hill.

We observed the field of GRB 250702F detected by Swift (Siegel, GCN 40894) with one of Skynet's PROMPT telescopes located at the Astronomical Observatory of the Jagiellonian University, two of Skynet's PROMPT telescopes located at the Cerro Tololo Inter-American Observatory, and a 0.4m telescope located at Hampden-Sydney College. Observations began roughly 2.5 minutes post trigger and continued for 8 hours.

We detect the optical afterglow (Siegel, GCN 40894; Jelinek, GCN 40895; Kumar GCN 40896; Lipunov GCN 40899; Martin-Carrillo GCN 40900; Talamantes GCN 40907; Becerra GCN 40911; Brivio GCN 40913; An GCN 40916) in the B, V, R, I, and r bands. We report the initial detection photometry below.

Inspection of the first 2.5 hours of photometry indicates a fading from ~15.5 mag (two minutes post-trigger) to ~18 mag (two-hours post-trigger) in R band. The light curve appears to plateau for the remaining 30 minutes. Analysis of the additional 5.5 hours of photometry is ongoing.

Exposure lengths were calculated using our automated exposure length scaling model.

Tmid - T0 (s) | Telescope   | Filter | Exposure (s) | Mag    | Mag Error
------------------------------------------------------------------------
153           | PROMPT-OAUJ | V      | 2            | 15.454 | 0.101
168           | PROMPT-OAUJ | R      | 2            | 15.447 | 0.118

Our images have been calibrated using stars from the APASS catalog. Magnitudes were not corrected for dust extinction.

GCN Circular 40916

Subject
GRB 250702F: TRT Optical Observation
Date
2025-07-03T14:23:55Z (3 months ago)
From
Zipei Zhu at NAOC <zpzhu@nao.cas.cn>
Via
Web form
J. An (NAOC), K. Noysena, K. Chanchaiworawit, S. Tinyanont (NARIT), S.Y. Fu (HUST), X. Liu, Z.P. Zhu, S.Q. Jiang, L.B. He, D. Xu (NAOC) report on behalf of a large collaboration:

We observed the field of GRB 250702F detected by Swift/BAT (Klingler et al., GCN 40894) and Fermi/GBM (Fermi GBM Team, GCN 40892), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Fresno, California, U.S.A. (SRO). Observations started at 05:17:25 UTC on 2025-07-03, i.e., ~ 8.18 hr after the Swift/BAT trigger and several frames in the R & I band were obtained. 

We clearly detect the optical afterglow (Jelinek et al., GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900; Angulo et al., GCN 40907; Becerra et al., GCN 40911; Brivio et al., GCN 40913) in our images. Preliminary photometry shows that the source has R ~ 19.4 mag at 8.32 hr post-trigger and I ~ 18.6 mag at 8.61 hr post-trigger, calibrated with Pan-STARRS DR2 catalog and not corrected for Galactic extinction.

GCN Circular 40913

Subject
GRB 250702F: REM optical afterglow detection
Date
2025-07-03T12:13:57Z (3 months ago)
From
Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it>
Via
Web form
R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team:

We observed the field of GRB 250702F detected by Swift/BAT (Klingler et al., GCN 40894) and Fermi/GBM (Fermi GBM Team, GCN 40892) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, and H bands, started on 2025 July 02 at 22:50:33 UT (i.e. 1.7 hr after the burst), and lasted for about 1 hour.

From preliminary inspection, we detect the counterpart in the optical images at the position of the optical afterglow (Klingler et al., GCN 40894; Jelinek et al., GCN 40895; Kumar et al., GCN 40896; Lipunov et al., GCN 40899; Martin-Carrillo et al., GCN 40900; de Ugarte Postigo et al., GCN 40901; Angulo et al., GCN 40907; Becerra et al., GCN 40911) with the following magnitude:

r = 18.3 +/- 0.2 (AB; calibrated against the Pan-STARRS catalogue),
at a mid-time of 1.7 hr after the trigger.

No NIR counterpart is detected down the following 3sigma upper limit:

H > 15.5 (Vega; calibrated against the 2MASS catalogue),
at a mid-time of 1.7 hr after the trigger.

GCN Circular 40911

Subject
GRB 250702F: DDOTI Optical Observation
Date
2025-07-03T10:35:15Z (3 months ago)
From
Rosa L. Becerra at Tor Vergata, Roma <rosa.becerra@roma2.infn.it>
Via
Web form
Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Sahil Atri (U Roma), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), Margarita Pereyra (UNAM) and Eleonora Troja (U Roma) report:

We observed the field of GRB 250702F detected by Swift (Klingler et al., GCN Circ. 40894) and Fermi/GBM (Fermi GBM Team, GCN Circ. 40892) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on the night of 2025-07-03 UTC. 

DDOTI observed the Swift/UVOT position (Klingler et al., GCN Circ. 40894) from 04:12 UTC to 08:31 UTC (from T+7.1 h to T+ 11.4 h after the trigger), obtaining a total exposure of 2.4 hours, alternating with other scientific programs.

Comparing our observations to Pan-STARRS PS1 DR2 catalogues, we detect the optical counterpart reported by Klingler et al. (GCN Circ. 40894), Jelinek et al. (GCN Circ. 40895), Kumar et al. (GCN Circ. 40896), Lipunov et al. (GCN Circ. 40899), Martin-Carrillo et al. (GCN Circ. 40900), de Ugarte Postigo et al. (GCN Circ. 40901) and Angulo et al. (GCN Circ. 40907) with an AB magnitude of: 

w = 19.85 +/- 0.05
 
This value is not corrected for the Galactic extinction.

We thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir.

GCN Circular 40907

Subject
GRB 250702F: COLIBRÍ Observations of the Afterglow
Date
2025-07-03T05:31:22Z (3 months ago)
From
Margarita Pereyra Talamantes at IA-UNAM Ensenada <mpereyra@astro.unam.mx>
Via
Web form
Camila Angulo (UNAM), Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Jean-Luc Atteia (IRAP), Fredd Alvarez (UNAM), Dalya Akl (AUS), Sarah Antier (OCA), Rosa L. Becerra (U Roma), Nathaniel R. Butler (ASU) , Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), N. A. Rakotondrainibe (LAM), Benjamin Schneider (LAM) and Antonio de Ugarte Postigo (LAM):

We imaged the field of the Swift GRB 250702F (Klingler et al., GCN Circ. 40894) using the DDRAGO wide-field imager on the COLIBRÍ telescope. We observed from 2025-07-03 03:53 to 04:03 UTC (from 6.78 to 6.95 hours after the trigger) and obtained 180 seconds of exposure in each of the g, r, and i filters.

The data were reduced and coadded with the COLIBRÍ pipeline and analysed with STDWeb/STDPipe (Karpov 2025). The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction.

We detected the optical counterpart reported by Klingler et al. (GCN Circ. 40894), Jelinek et al. (GCN Circ. 40895), Kumar et al. (GCN Circ. 40896), Lipunov et al (GCN Circ. 40899), Martin-Carrillo et al. (GCN Circ. 40900),  and de Ugarte Postigo et al (GCN Circ. 40901) at a preliminary magnitude of:

g = 19.60 +/- 0.03 
r = 19.52 +/- 0.03
i = 19.24 +/- 0.03

Further observations are ongoing.

We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams.

COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico.

GCN Circular 40902

Subject
GRB 250702F: Enhanced Swift-XRT position
Date
2025-07-03T00:08:06Z (3 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2088 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 250702F, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 212.93584, +16.74909 which is equivalent
to:

RA (J2000): 14h 11m 44.60s
Dec (J2000): +16d 44' 56.7"

with an uncertainty of 2.2 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.

GCN Circular 40901

Subject
GRB 250702F: GTC/OSIRIS+ spectroscopic redshift z = 1.520
Date
2025-07-02T23:48:29Z (3 months ago)
From
Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>
Via
Web form
A. de Ugarte Postigo (LAM), A. Martin-Carrillo (UCD), D. B. Malesani (DAWN/NBI and Radboud), G. Lombardi (GTC), J. F. Agui Fernandez (CAHA), M. A. Aloy (UV), J. P. U. Fynbo (DAWN/NBI), L. Galbany (IEEC-CSIC), S. Geier (GTC), L. Izzo (INAF/OACN and DARK/NBI), N. A. Rakotondrainibe (LAM), B. Schneider (LAM), N. R. Tanvir (Univ. Leicester), C. C. Thoene (AbAO), F. Pérez (GTC), D. l. Pérez Valladares (GTC) and A. Tejero Caro (GTC) report:

We observed the optical afterglow of GRB 250702F detected by Swift (Klingler et al., GCN 40894) and Fermi (Fermi GBM team, GCN 40892), using the 10.4 m GTC located at the Roque de los Muchachos Observatory in the island of La Palma (Spain) equipped with the OSIRIS+ instrument.

Our spectroscopic observations started on 2025-07-02 at 22:36:29 UT (1.496 hr after the Swift trigger) and consisted of 2x420 s exposures using grism R1000B, which covers the wavelength range between 3600 and 7700 AA.

On top of the bright continuum, a number of clear absorption features are detected. Among many, we identify C IV, Al II, Al III, Fe II, Mg II, Mg I, all at a common redshift z = 1.520. This is likely the redshift of GRB 250702F.

GCN Circular 40900

Subject
GRB 250702F: NOT observations of the optical afterglow
Date
2025-07-02T23:14:56Z (3 months ago)
From
Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>
Via
Web form
A. Martin-Carrillo (UCD), D. B. Malesani (DAWN/NBI and Radboud), G. Corcoran (UCD), B. P. Gompertz (Birmingham), A. de Ugarte Postigo (LAM), A. K. Haris-Kiss (Helsinki Univ.), N. Routamo (Helsinki Univ.), A. A. Djupvik (NOT) report on behalf of a larger collaboration:

We observed the field of GRB 250702F detected by Swift (Klingler et al., GCN 40894) and Fermi (Fermi GBM team, GCN 40892), using the StanCam camera mounted on the Nordic Optical Telescope (NOT). We obtained 3x90 s exposures in each of the Bessel-R and SDSS g and i bands, starting at 22:24 UT on 2025-07-02 (77 min after the Swift trigger). 

The optical afterglow reported by Swift/UVOT (Klingler et al., GCN 40894), Ondrejov D50 (Jelinek et al., GCN 40895), GOTO (Kumar et al., GCN 40896) and MASTER (Lipunov et al., GCN 40899) is well detected in all bands. We measure the following coordinates (J2000, calibrated against Gaia stars):

RA = 14:11:44.65
Dec = +16:44:54.7

The object had a magnitude 

r = 17.99 +/- 0.08 (AB).

The photometric calibration was performed using nearby stars from the Pan-STARRS catalog and the magnitude is not corrected for Galactic extinction.

GCN Circular 40899

Subject
GRB 250702F: MASTER optical afterglow observation
Date
2025-07-02T22:49:02Z (3 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
V.Lipunov (Lomonosov MSU), D.Buckley (SAAO),
A.Kuznetsov, E.Gorbovskoy, G.Antipov, P.Balanutsa, A.Chasovnikov, N.Tiurina, V.Topolev, K.Zhirkov, Ya.Kechin, V.Senik, D.Vlasenko (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile,  F. Podesta, R.Podesta, E. Gonzalez (OAFA),
A.Sosnovskij (Crao RAS),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez,
J.Martinez,A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro  Astrophysics Observatory

MASTER-SAAO robotic telescope (MASTER Global Robotic Net http://observ.pereplet.ru, Lipunov et al. 2010, Advances in Astronomy, v.2010, 30L)
located in South African Astronomical Observatory,
pointed (Lipunov et al. GCN 40893) to Fermi (GCN 40892) and Swift GRB 250702F  (Klingler et al., GCN 40894, Ttrigger=21:06:43.27UT)
in two polarization filters at 2025-07-02 21:24:39 UT ( https://master.sai.msu.ru/site/master2/observ.php?id=2923573 ).

There is MASTER OT J141144.70+164454.6 with m_OT~16.2 with preliminary significant polarization.
This GRB 250702F counterpartwas discovered by Swift (GCN 40894) and also reported by Ondrejov D50 (Jelinek et al., GCN 20895)
and GOTO (Kumar et al. GCN 40896) observatories.

Observation and reduction will be continued.

GCN Circular 40898

Subject
Fermi GRB 250702F: Global MASTER-Net observations report
Date
2025-07-02T22:15:54Z (3 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, 
G.Antipov,  A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile,  F. Podesta, R.Podesta, E. Gonzalez  (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250702F ( Fermi GBM team, GCN 40892) errorbox  1045 sec after notice time and 1076 sec after trigger time at 2025-07-02 21:24:39 UT, with upper limit up to  17.6 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -70.5 deg. 

The galactic latitude b = 66 deg., longitude l = 12 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2923618

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    1106 | 2025-07-02 21:24:39 |         MASTER-SAAO | (14h 11m 15.13s , +16d 44m 54.1s) |  P/ |    60 | 16.2 |        
    1106 | 2025-07-02 21:24:39 |         MASTER-SAAO | (14h 09m 27.09s , +17d 00m 11.2s) | P\\ |    60 | 16.2 |        
    1185 | 2025-07-02 21:25:58 |         MASTER-SAAO | (14h 11m 15.31s , +16d 44m 57.8s) |  P/ |    60 | 16.8 |        
    1185 | 2025-07-02 21:25:58 |         MASTER-SAAO | (14h 09m 27.34s , +17d 00m 16.0s) | P\\ |    60 | 16.7 |        
    1265 | 2025-07-02 21:27:17 |         MASTER-SAAO | (14h 11m 15.50s , +16d 45m 01.2s) |  P/ |    60 | 16.9 |        
    1265 | 2025-07-02 21:27:17 |         MASTER-SAAO | (14h 09m 27.59s , +17d 00m 19.8s) | P\\ |    60 | 16.8 |        
    1344 | 2025-07-02 21:28:36 |         MASTER-SAAO | (14h 11m 15.81s , +16d 45m 05.4s) |  P/ |    60 | 13.8 |        
    1344 | 2025-07-02 21:28:36 |         MASTER-SAAO | (14h 09m 27.96s , +17d 00m 24.8s) | P\\ |    60 | 13.2 |        
    1423 | 2025-07-02 21:29:55 |         MASTER-SAAO | (14h 11m 16.13s , +16d 45m 08.4s) |  P/ |    60 | 15.0 |        
    1423 | 2025-07-02 21:29:55 |         MASTER-SAAO | (14h 09m 28.25s , +17d 00m 28.2s) | P\\ |    60 | 15.3 |        
    1502 | 2025-07-02 21:31:14 |         MASTER-SAAO | (14h 11m 16.47s , +16d 45m 11.2s) |  P/ |    60 | 17.0 |        
    1502 | 2025-07-02 21:31:14 |         MASTER-SAAO | (14h 09m 28.60s , +17d 00m 32.0s) | P\\ |    60 | 17.0 |        
    1581 | 2025-07-02 21:32:33 |         MASTER-SAAO | (14h 09m 28.93s , +17d 00m 35.2s) | P\\ |    60 | 15.3 |        
    1581 | 2025-07-02 21:32:33 |         MASTER-SAAO | (14h 11m 16.74s , +16d 45m 14.1s) |  P/ |    60 | 15.2 |        
    1660 | 2025-07-02 21:33:53 |         MASTER-SAAO | (14h 11m 17.19s , +16d 45m 17.6s) |  P/ |    60 | 16.2 |        
    1660 | 2025-07-02 21:33:53 |         MASTER-SAAO | (14h 09m 29.37s , +17d 00m 38.9s) | P\\ |    60 | 16.4 |        
    1739 | 2025-07-02 21:35:12 |         MASTER-SAAO | (14h 09m 29.75s , +17d 00m 41.8s) | P\\ |    60 | 16.2 |        
    1739 | 2025-07-02 21:35:12 |         MASTER-SAAO | (14h 11m 17.59s , +16d 45m 20.3s) |  P/ |    60 | 16.2 |        
    1818 | 2025-07-02 21:36:31 |         MASTER-SAAO | (14h 11m 18.09s , +16d 45m 23.6s) |  P/ |    60 | 15.3 |        
    1818 | 2025-07-02 21:36:31 |         MASTER-SAAO | (14h 09m 30.27s , +17d 00m 45.5s) | P\\ |    60 | 15.5 |        
    1897 | 2025-07-02 21:37:50 |         MASTER-SAAO | (14h 11m 18.42s , +16d 45m 25.8s) |  P/ |    60 | 15.4 |        
    1897 | 2025-07-02 21:37:50 |         MASTER-SAAO | (14h 09m 30.60s , +17d 00m 47.9s) | P\\ |    60 | 14.9 |        
    1977 | 2025-07-02 21:39:09 |         MASTER-SAAO | (14h 11m 18.98s , +16d 45m 28.9s) |  P/ |    60 | 14.7 |        
    1977 | 2025-07-02 21:39:09 |         MASTER-SAAO | (14h 09m 31.18s , +17d 00m 51.7s) | P\\ |    60 | 14.9 |        
    2056 | 2025-07-02 21:40:28 |         MASTER-SAAO | (14h 11m 19.57s , +16d 45m 31.9s) |  P/ |    60 | 15.2 |        
    2056 | 2025-07-02 21:40:28 |         MASTER-SAAO | (14h 09m 31.82s , +17d 00m 54.9s) | P\\ |    60 | 15.1 |        
    2135 | 2025-07-02 21:41:47 |         MASTER-SAAO | (14h 11m 20.15s , +16d 45m 34.6s) |  P/ |    60 | 16.4 |        
    2135 | 2025-07-02 21:41:47 |         MASTER-SAAO | (14h 09m 32.32s , +17d 00m 58.0s) | P\\ |    60 | 16.2 |        
    2214 | 2025-07-02 21:43:07 |         MASTER-SAAO | (14h 11m 20.70s , +16d 45m 37.3s) |  P/ |    60 | 15.3 |        
    2214 | 2025-07-02 21:43:07 |         MASTER-SAAO | (14h 09m 32.93s , +17d 01m 00.9s) | P\\ |    60 | 15.5 |        
    2293 | 2025-07-02 21:44:26 |         MASTER-SAAO | (14h 09m 33.46s , +17d 01m 03.5s) | P\\ |    60 | 16.5 |        
    2293 | 2025-07-02 21:44:26 |         MASTER-SAAO | (14h 11m 21.30s , +16d 45m 40.0s) |  P/ |    60 | 16.4 |        
    2372 | 2025-07-02 21:45:45 |         MASTER-SAAO | (14h 11m 21.94s , +16d 45m 43.1s) |  P/ |    60 | 16.2 |        
    2372 | 2025-07-02 21:45:45 |         MASTER-SAAO | (14h 09m 34.12s , +17d 01m 07.1s) | P\\ |    60 | 16.5 |        
    2452 | 2025-07-02 21:47:04 |         MASTER-SAAO | (14h 11m 22.55s , +16d 45m 45.7s) |  P/ |    60 | 16.1 |        
    2452 | 2025-07-02 21:47:04 |         MASTER-SAAO | (14h 09m 34.75s , +17d 01m 09.9s) | P\\ |    60 | 15.6 |        
    2531 | 2025-07-02 21:48:23 |         MASTER-SAAO | (14h 11m 23.17s , +16d 45m 48.6s) |  P/ |    60 | 14.8 |        
    2531 | 2025-07-02 21:48:23 |         MASTER-SAAO | (14h 09m 35.46s , +17d 01m 13.1s) | P\\ |    60 | 14.8 |        
    2610 | 2025-07-02 21:49:42 |         MASTER-SAAO | (14h 09m 36.55s , +17d 01m 14.5s) | P\\ |    60 | 16.8 |        
    2610 | 2025-07-02 21:49:42 |         MASTER-SAAO | (14h 11m 23.57s , +16d 45m 50.8s) |  P/ |    60 | 17.1 |        
    2689 | 2025-07-02 21:51:02 |         MASTER-SAAO | (14h 11m 24.20s , +16d 45m 53.3s) |   C |    60 | 17.4 |        
    2689 | 2025-07-02 21:51:02 |         MASTER-SAAO | (14h 09m 37.19s , +17d 01m 17.3s) |   C |    60 | 17.0 |        
    2768 | 2025-07-02 21:52:21 |         MASTER-SAAO | (14h 09m 37.95s , +17d 01m 20.6s) |   C |    60 | 16.9 |        
    2768 | 2025-07-02 21:52:21 |         MASTER-SAAO | (14h 11m 24.97s , +16d 45m 56.2s) |   C |    60 | 17.6 |        
    2847 | 2025-07-02 21:53:40 |         MASTER-SAAO | (14h 11m 25.79s , +16d 45m 59.0s) |   C |    60 | 17.6 |        
    2847 | 2025-07-02 21:53:40 |         MASTER-SAAO | (14h 09m 38.78s , +17d 01m 23.7s) |   C |    60 | 17.0 |        
    2926 | 2025-07-02 21:54:58 |         MASTER-SAAO | (14h 11m 26.61s , +16d 46m 02.5s) |   C |    60 | 16.4 |        
    2926 | 2025-07-02 21:54:58 |         MASTER-SAAO | (14h 09m 39.68s , +17d 01m 27.7s) |   C |    60 | 15.7 |        
    3005 | 2025-07-02 21:56:18 |         MASTER-SAAO | (14h 11m 27.41s , +16d 46m 05.2s) |   C |    60 | 17.1 |        
    3005 | 2025-07-02 21:56:18 |         MASTER-SAAO | (14h 09m 40.45s , +17d 01m 30.5s) |   C |    60 | 16.4 |        
    3242 | 2025-07-02 22:00:15 |         MASTER-SAAO | (14h 09m 43.34s , +17d 01m 40.5s) |   C |    60 | 15.6 |        
    3242 | 2025-07-02 22:00:15 |         MASTER-SAAO | (14h 11m 30.25s , +16d 46m 14.4s) |   C |    60 | 16.4 |        
    3321 | 2025-07-02 22:01:33 |         MASTER-SAAO | (14h 11m 30.94s , +16d 46m 16.3s) |   C |    60 | 16.8 |        
    3321 | 2025-07-02 22:01:33 |         MASTER-SAAO | (14h 09m 44.09s , +17d 01m 43.0s) |   C |    60 | 15.8 |        
    3400 | 2025-07-02 22:02:52 |         MASTER-SAAO | (14h 09m 44.99s , +17d 01m 45.7s) |   C |    60 | 15.7 |        
    3400 | 2025-07-02 22:02:52 |         MASTER-SAAO | (14h 11m 31.94s , +16d 46m 18.9s) |   C |    60 | 16.9 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.

GCN Circular 40896

Subject
GRB 250702F: GOTO optical counterpart detection
Date
2025-07-02T22:04:31Z (3 months ago)
From
Amit Kumar at Royal Holloway - UoL/ U of Warwick, UK <amitkundu515@gmail.com>
Via
Web form
A. Kumar, D. O’Neill, B. P. Gompertz, R. Starling, K. Ackley, M. J. Dyer, J. Lyman, K. Ulaczyk, B. Godson, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, G. Ramsay, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, and J. Casares report on behalf of the GOTO collaboration:

We report on optical observations with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022; Dyer et al. 2024) in response to the Swift/BAT and Fermi/GBM detected GRB 250702F (Klingler et al., GCN 40894; Fermi GBM Team, GCN 40892). Targeted observations were performed by GOTO-North at 2025-07-02 21:33:58 (27.25 minutes post-trigger). The observation consisted of 4x90s exposures in the GOTO L-band (400-700 nm).

Images were processed immediately after acquisition using the GOTO pipeline. 

We detect the optical afterglow reported by Swift/UVOT (Klingler et al., GCN 40894) and Ondrejov D50 (Jelinek et al., GCN 40895) with an L-band magnitude of 17.12 ± 0.07 (AB).

Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction. Observations are ongoing. 

GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC).

GCN Circular 40895

Subject
GRB 250702F: Ondrejov D50 optical afterglow detection
Date
2025-07-02T21:46:43Z (3 months ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Via
email
M. Jelinek, F. Novotny, A. Malenakova, J. Strobl, R. Hudec, C. Polasek (ASU CAS Ondrejov) report:We are observing the position of the Swift-detected GRB 250702F (trigger #1329888, very likely identical to Fermi GBM trigger #773183208) with the D50 robotic telescope of the Astronomical Institute Ondrejov, near Prague, Czech Republic. We initially performed a series of 20s unfiltered exposures starting 27.8s after the Swift trigger.
We clearly detect a possible optical afterglow in single 20s images at 14:11:44.6s +16:44:55 (J2000, 212.935979, +16.748483). The forward shock component peaked at unfiltered magnitude ~15.1 approximately 4 minutes post-GRB and shows a slow decay during our ongoing observations.
Further observations and detailed photometry are in progress.

GCN Circular 40894

Subject
GRB 250702F: Swift detection of a burst with an optical counterpart
Date
2025-07-02T21:42:54Z (3 months ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
Via
email
N. J. Klingler (GSFC/UMBC/CRESSTII), A. D'Ai (INAF-IASFPA),
R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), T. M. Parsotan (GSFC) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 21:06:43.27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 250702F (trigger= 1329888).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 212.933, +16.699 which is 
   RA(J2000) = 14h 11m 44s
   Dec(J2000) = 16d 41' 57"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked structure
with a duration of about 70 sec. The peak count rate was ~4000 counts/sec 
(15-350 keV), at ~38 sec after the trigger.

The XRT began observing the field at 21:08:11.7 UT, 88.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 212.9378, 16.7475 which is equivalent to:
   RA(J2000)  = 14h 11m 45.07s
   Dec(J2000) = +16d 44' 51.0"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 175 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy.

The initial flux in the 2.5 s image was 5.48e-09 erg cm^-2 s^-1 (0.2-10
keV).

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 97 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	14:11:44.69 = 212.93622
  DEC(J2000) = +16:44:55.0  =  16.74861
with a 90%-confidence error radius of about 0.74 arc sec. This position is 6.7
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.85 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.017.

This burst is spatially and temporally coincident with the burst reported by Fermi GBM (GCN Circ. 40892).

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu).
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/)

GCN Circular 40893

Subject
Swift GRB 250702F: Global MASTER-Net observations report
Date
2025-07-02T21:36:54Z (3 months ago)
Edited On
2025-07-10T14:16:54Z (3 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Vladimir Lipunov at Lomonosov Moscow State University <lipunov@sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, 
G.Antipov,  A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile,  F. Podesta, R.Podesta, E. Gonzalez  (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB250702.88 (trigger No 1329888,14h 11m 43.92s , +16d 41m 56.4s, R=0.05) errorbox  1057 sec after notice time and 1076 sec after trigger time at 2025-07-02 21:24:39 UT, with upper limit up to  16.9 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -70.5 deg. 

The galactic latitude b = 68 deg., longitude l =  8 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2923573

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

    1106 |         MASTER-SAAO |  P/ |    60 | 16.2 |        
    1106 |         MASTER-SAAO | P\\ |    60 | 16.2 |        
    1185 |         MASTER-SAAO |  P/ |    60 | 16.8 |        
    1185 |         MASTER-SAAO | P\\ |    60 | 16.7 |        
    1264 |         MASTER-SAAO |  P/ |    60 | 16.9 |        
    1264 |         MASTER-SAAO | P\\ |    60 | 16.8 |        
    1343 |         MASTER-SAAO |  P/ |    60 | 13.8 |        


The observation and reduction will continue. 
The message may be cited.

GCN Circular 40892

Subject
GRB 250702F: Fermi GBM Final Real-time Localization
Date
2025-07-02T21:17:16Z (3 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB

At 21:06:43 UT on 2 Jul 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250702F (trigger 773183208.102296 / 250702880).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 215.8, Dec = 16.6 (J2000 degrees, equivalent to J2000 14h 23m, 16d 36'), with a statistical uncertainty of 2.2 degrees.

The angle from the Fermi LAT boresight is 43.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250702880/quicklook/glg_skymap_all_bn250702880.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250702880/quicklook/glg_healpix_all_bn250702880.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250702880/quicklook/glg_lc_medres34_bn250702880.gif
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