GRB 251014A

A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato
(INAF-OAB), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows
(PSU), S. Lanava (PSU), J.P. Osborne (U. Leicester) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:

We have analysed 6.2 ks of Photon Counting (PC) mode XRT data for GRB
251014A, collected between T0+101.1 ks and T0+174.7 ks. 

Three uncatalogued X-ray sources have been detected within the
estimated 3-sigma Swift-BAT error region (296 arcsec), however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the
afterglow. Details of these sources are given below:

Source 5:
  RA (J2000.0):  111.7316  =  07h 26m 55.58s
  Dec (J2000.0): +6.4150  =  +06d 24' 53.9"
  Error: 6.7 arcsec (radius, 90% conf.)
  Count-rate: (2.33 [+0.88, -0.72])e-3 ct s^-1	 
  Distance: 1 arcsec from Swift-BAT position.
  Flux: (1.11 [+0.42, -0.34])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 8:
  RA (J2000.0):  111.6918  =  07h 26m 46.04s
  Dec (J2000.0): +6.4252  =  +06d 25' 30.7"
  Error: 6.1 arcsec (radius, 90% conf.)
  Count-rate: (2.25 [+0.88, -0.72])e-3 ct s^-1	 
  Distance: 148 arcsec from Swift-BAT position.
  Flux: (7.1 [+2.8, -2.3])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 9:
  RA (J2000.0):  111.7868  =  07h 27m 08.82s
  Dec (J2000.0): +6.3731  =  +06d 22' 23.3"
  Error: 5.6 arcsec (radius, 90% conf.)
  Count-rate: (1.42 [+0.73, -0.56])e-3 ct s^-1	 
  Distance: 247 arcsec from Swift-BAT position.
  Flux: (4.8 [+2.5, -1.9])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Seven uncatalogued sources were also detected too far from the GRB
position to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/01403878.

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

M. J. Moss (GSFC), E. Ambrosi (INAF-IASFPA),
S. D. Barthelmy (GSFC), R. Gupta (GSFC),
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-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 251014A (trigger #1403878)
(Ambrosi, et al., GCN Circ. 42238
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 ).  The BAT ground-calculated position is
RA, Dec = 111.728, 6.420 deg which is 
   RA(J2000)  =  07h 26m 54.7s 
   Dec(J2000) = +06d 25' 10.7" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.
 
The BAT mask-weighted light curve shows a single peaked emission with total 
duration of less than 2 sec. T90 (15-350 keV) is 1.56 +- 0.24 sec (estimated error 
including systematics).
 
The time-averaged spectrum from T-0.07 to T+1.82 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.82 +- 0.70, 
and Epeak of 47.1 +- 9.2 keV (chi squared 60.50 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.3 +- 0.2 x 10^-07 erg/cm2
and the 1-sec peak flux measured from T-0.07 sec in the 15-150 keV band is
2.8 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.90 +- 0.13 (chi squared 69.47 for 57 d.o.f.).  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/1403878

J. Durbak (UMD), O. Guiffreda (UMD), N. Passaleva (U Rome), M. Elkabir (U Rome), A. S. Kutyrev (NASA/GSFC), E. Troja (U Rome), S. B. Cenko (NASA/GSFC)

Following the Swift BAT (Ambrosi et al, GCN 42238
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 ) and Fermi GBM (Fermi GBM Team, GCN 42237
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 ) detection, we observed the transient field in J-filter with PRIME ~1 hour after Swift and Fermi detection.

After comparing a previous J-band epoch observed in this location on 2024-11-17, we detect no new sources in J-band within the Swift BAT localization region. Using nearby 2MASS stars for preliminary calibration we derive a limiting magnitude >19.7 AB for the previous epoch, not corrected for Galactic extinction.

Further observations are planned to obtain deeper imaging.

PRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa at the South African Astronomical Observatory (SAAO) (Kutyrev et al. 2023, Yama et al. 2023, Durbak et al. 2024).

We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations.

R. Woolf, C.C. Cheung, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
 
The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 251014A, which was also detected by Fermi/GBM (GCN 42237
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 , 42249
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 ) and Swift/BAT (GCN 42238
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 ). 

Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2025-10-14 00:28:30.032 with a duration of 1.02 s and a total significance of about 9.9 sigma. The light curve is dominated by a single peak.

The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
 
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC.  It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS, and operated until 2024 April when it was put in safe storage on orbit. Glowbug was removed from storage and resumed operation on 2025 September 12.
 
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
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[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108
 
Distribution Statement A: Approved for public release.  Distribution is unlimited.

Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Camila Angulo Valdez (UNAM), Sahil Atri (U Roma), 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 251014A detected by Fermi/GBM (Fermi GBM Team, GCN Circ. 42237
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 ) and Swift (Ambrosi et al., GCN Circ. 42238
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 ) 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 2025-10-14 UTC.

DDOTI observed the Swift/BAT position (Ambrosi et al., GCN Circ. 42238
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 ) from 09:12 UTC to 12:27 UTC (from T+8.7 h to T+ 11.9 h after the trigger), obtaining a total exposure of 70 minutes, alternating with other scientific programs.

Comparing our observations to the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we detect no uncatalogued fading sources within the observed field down to a 5-sigma limiting AB magnitude of:

w >20.3

This value is consistent with the reported by the SAO RAS collaboration (Moskvitin et al. GCN Circ. 42250
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 ) and is not corrected for the Galactic extinction.

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

A. S. Moskvitin, O. I. Spiridonova (SAO RAS),
report on behalf of GRB follow-up team.

We observed the field of the GRB 251014A (Ambrosi et al., GCN 42238
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 ;
The Fermi GBM team, GCN 42237
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 ; de Barra et al., GCN 42249
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 ) 
with the 1-m SAO RAS telescope Zeiss-1000 equipped 
with the CCD-photometer. We obtained 7 x 300 sec. images in Rc band 
under mediocre weather conditions on 2025.10.14, 00:51:01--01:38:56 UT 
(t_mid - T0 = 0.77458 hours).

Within our FOV (covers ~80% of northern part of Swift-BAT error 
circle) we do not detect any new source down to the limiting 
magnitude of R_lim = 21.5. The field calibrated against nearby 
USNO-B1.0 stars (R2 magnitudes) and not corrected for the Galactic 
extinction.

C. de Barra (University College Dublin), J. Smith (UAH), C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 00:28:30.34 UT on 14 October 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 251014A (trigger 782094515/251014020).
which was also detected by Swift BAT (E. Ambrosi et al. 2025, GCN 42238
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 ).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight is 44 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 1.7 s (50-300 keV). The time-averaged spectrum
from T0-0.2 to T0+1.7 s is best fit by
a simple power law function with index -1.78 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
(6.2 +/- 0.5)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.32 s in the 10-1000 keV band is 6 +/- 1 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/"

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 GRB 251014A ( E. Ambrosi et al., GCN 42238
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 ) errorbox  26 sec after notice time and 361 sec after trigger time at 2025-10-14 00:34:31 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 68 deg. The sun  altitude  is -39.4 deg. 

The galactic latitude b = 11 deg., longitude l = 212 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=3014236

We obtain a following upper limits.  

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

     391 |         MASTER-SAAO |   C |    60 | 18.5 |        
Filter C is a clear (unfiltred) band. 


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

E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR),
R. Gupta (NASA GSFC) and D. M. Palmer (LANL) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 00:28:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 251014A (trigger=1403878).  Swift did not slew immediately
due to an observation constraint.
The BAT on-board calculated location is 
RA, Dec 111.732, +6.415 which is 
   RA(J2000) = 07h 26m 56s
   Dec(J2000) = +06d 24' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 1.5 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 21:52 UT on 2025 October 14. There will thus be no XRT
or UVOT data for this trigger before this time.

Burst Advocate for this burst is E. Ambrosi (elena.ambrosi 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/)

The Fermi GBM team reports the detection of a likely SHORT GRB

At 00:28:30 UT on 14 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251014A (trigger 782094515.336852 / 251014020).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 114.7, Dec = 7.4 (J2000 degrees, equivalent to J2000 07h 38m, 7d 24'), with a statistical uncertainty of 8.3 degrees.

The angle from the Fermi LAT boresight is 45.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251014020/quicklook/glg_skymap_all_bn251014020.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/bn251014020/quicklook/glg_healpix_all_bn251014020.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251014020/quicklook/glg_lc_medres34_bn251014020.gif