TITLE: GCN CIRCULAR NUMBER: 43481 SUBJECT: GRB 260101A: 239Alferov CubeSat detection DATE: 26/01/20 20:52:27 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru> D. Svinkin (Ioffe), D. Frederiks (Ioffe), D. Kapshtan (Geoscan), M. Orlov (Geoscan), V. Bazunova (Geoscan), E. Shchepin (Geoscan), E. Meltsov (Geoscan), K. Starikov (Geoscan, SPbSU), A. Khogoev (Geoscan), A. Razdobarin (SPbAU), and D. Dolmatov (SPbSU), on behalf of the 239Alferov team, report: The long-duration GRB 260101A (Fermi-GBM detection: The Fermi GBM team, GCN 43284; Hristov and Meegan, GCN 43297; Swift-BAT detection: Cenko et al., GCN 43285; Markwardt et al., GCN 43354; SVOM-GRM detection: Yu et al., GCN 43292; GECAM-B detection: Wang et al., GCN 43294; Konus-Wind detection: Svinkin et al., GCN 43389) was detected by 239Alferov 3U CubeSat at about 00:56:30 UT. The burst light curve, as measured by 239Alferov detector, shows a multipeaked structure very similar to that observed by other IPN instruments. The total burst duration duration is ~28 s. The emission is seen up to ~500 keV. The light curve recorded by 239Alferov is available at: http://www.ioffe.ru/LEA/GRBs/GRB260101_T03419/239Alferov/ 239Alferov is an educational 3U CubeSat mission at SSO combining amateur radio and space research objectives. The gamma-ray detector onboard 239Alferov contains a 64x72x15 mm NaI(Tl) scintillator read out by a SiPM array and covers the energy range from ~20 keV to ~1000 keV. The spacecraft is now at a commissioning stage, with scientific observations started in December 2025. Currently, the instrument records count rates in five energy bands: ~20-50 keV, ~50-100 keV, ~100-500 keV, 500-1000 keV, and > 1000 keV, with 1 s temporal resolution. The surveys span a couple of days with about a day-long analysis and maintenance intervals between the observations. The ground segment of the mission utilizes the SONIKS open ground station network. View this GCN Circular online at https://gcn.nasa.gov/circulars/43481. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...