TITLE: GCN CIRCULAR NUMBER: 45005 SUBJECT: GRB 260604A: 239Alferov CubeSat detection DATE: 26/06/19 14:48:42 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 260604A (Fermi-GBM detection: The Fermi GBM team, GCN 44812; Glowbug detection: Cheung et al., GCN 44845; SVOM-GRM detection: Yu et al., GCN 44863) was detected by 239Alferov 3U CubeSat at about 8668 s (02:24:28) UT. The burst was also detected by Konus-Wind in the waiting mode. The burst light curve, as measured by 239Alferov detector, shows a single pulse with a duration of ~5 s. The emission is seen up to ~500 keV. The light curve recorded by 239Alferov is available at: http://www.ioffe.ru/LEA/239Alferov/260604A/ 239Alferov GRB detections are listed at: http://www.ioffe.ru/LEA/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. 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 0.5 s temporal resolution. The ground segment of the mission utilizes the SONIKS open ground station network. View this GCN Circular online at https://gcn.nasa.gov/circulars/45005. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...