Transient Alerts — HabitableZone

Transient Alerts

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In plain words Notable

A burst of gamma rays (the most energetic form of light) was caught on 7 October 2026 by the SVOM satellite, Fermi, and several other space telescopes. It came from a patch of sky toward the constellation Cetus, and the Einstein Probe X-ray telescope also saw it. Within minutes, ground telescopes found a fading optical (visible-light) glow at the spot, and later X-ray and infrared detections confirmed it. A spectrum from the Very Large Telescope in Chile put the burst at redshift 2.101, which means the light left about 10 billion years ago. The burst lasted roughly 23 seconds, which fits the long kind of gamma-ray burst, usually produced when a massive star collapses. The glow faded from about magnitude 15 in the first minutes to about 21.6 a day later. That is a normal fading pattern for an afterglow.

How unusual is it? Most gamma-ray bursts have no measured distance, but this one has a secure spectroscopic redshift of 2.101 and a bright, well-followed afterglow seen in optical, infrared and X-ray light. That makes it notable, but it is otherwise an ordinary long burst, not one of the record-setters.

Written by an AI model (claude-sonnet-5-5) from the official reports in this thread, and rewritten as new reports arrived (version 4); last updated . It may contain mistakes: the reports themselves are the authority.

GRB 261007A — GRB, X-ray Transient
GCN Circulars —

GCN Circular 45824
GRB 261007A: SVOM detection of a burst
From: SVOM_group
Issued: 2026-10-07 06:31 UTC
Type: GRB, X-ray Transient
Why this event is posted: every one of the gamma-ray bursts is posted.

Hatsune Goto (RIKEN/CEA), Renjie Xiong(GXU), Donghua Zhao (NAOC), Wenlong Zhang(PMO), Xiao Tian(GXU), report on behalf of the SVOM mission team:

At 2026-10-07T05:42:03 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 261007A (SVOM burst-id sb26100701).

The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.

The burst was only detected by the Image Trigger (IMT), which produced a sequence of 4 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 8.19 in the [5-20] keV energy band over a time window of 327.68 seconds starting at 2026-10-07T05:37:58.

The localization of the best alert is R.A., Dec. 11.5787, -17.6698 degrees:
R.A. (J2000) = 0h46m18.89s
Dec. (J2000) = -17d40m11.38s
with a 90% confidence level (C.L.) radius of 9.61 arcmin (including systematic error of 2 arcmin added in quadrature).

This burst also triggered SVOM/GRM at 2026-10-07T05:39:49 with an SNR of 5.30.

SVOM slewed to the burst.
The observations of MXT and VT will be reported in future circulars.

The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE.

The Burst Advocate (BA) on shift for this alert is Xiao Tian: tianxiao@st.gxu.edu.cn.
Please contact the BA by email if you require additional information.

Every one of the gamma-ray bursts GCN reports is posted here.
Relayed automatically from NASA's General Coordinates Network.

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