GCN Circular 45296
Subject
GRB 260708A: cubesat Avion detection
Event
Date
2026-08-06T08:47:21Z (2 months ago)
From
Andrey Bogomolov at Moscow State University <aabboogg@srd.sinp.msu.ru>
Via
email
From Andrey Bogomolov at Moscow State University <aabboogg@srd.sinp.msu.ru>
A. Bogomolov, V. Bogomolov, A. Iyudin, S. Svertilov, N. Vasiliev
on behalf of the MSU “Sozvezdie-270” team, report:
At 2026-07-08 ~10:11:16 UT the long-duration GRB 260708A (Fermi/GBM detection: GCN #45115, Fermi/LAT detection: GCN #45117, GCN #45145, IceCube observation: GCN #45120, GCN #45134, GCN #45171, GECAM-B detection: GCN #45126, Glowbug detection: GCN #45130) was detected by the DeCoR-1 and DeCoR-3 instruments on the cubesat Avion of the Moscow University project “Sozvezdie-270” [1].
Total amount of photons detected by Avion is 403 (energy band >40 keV), it corresponds to a fluence of ~1.8*10^(-6) erg/cm^2 in the range 40-500 keV.
LC in the energy range of 40-500 keV is a single episode, a maximum flux is ~2.6 phot/(cm^2*s) at ~10 s after the start of the burst.
А total duration (T90) of the burst is ~25 s.
The light curve obtained by Avion is available here:
https://swx.sinp.msu.ru/models/grb_cat/data/pictures/GRB260708A_LC_Avion.png
Parameters of GRB 260708A as well as other GRBs detected by Moscow University cubesats are listed at: https://swx.sinp.msu.ru/models/grb_cat/grb.php?lang=en
Avion is one of 5 cubesats of the Moscow University project “Sozvezdie-270” [1] launched on 2023 June 27. The payload of Avion is a set of scintillation gamma-ray detectors DeCoR [2], the energy range is >30 keV, the time resolution is 0.5s.
[1] Svertilov et al. 2023 https://link.springer.com/chapter/10.1007/978-3-031-50248-4_21
[2] Bogomolov et al. 2026 Cosmic Research 64, 262 https://link.springer.com/article/10.1134/S0010952526600071