{
  "submitter": "Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>",
  "bibcode": "2026GCN.43612....1S",
  "createdOn": 1770135160396,
  "eventId": "GRB 260121A",
  "body": "D. Svinkin (Ioffe), D. Frederiks (Ioffe), D. Kapshtan (Geoscan), M. Orlov (Geoscan), \nV. Bazunova (Geoscan), E. Shchepin (Geoscan), E. Meltsov (Geoscan), \nK. Starikov (Geoscan, SPbSU), A. Khogoev (Geoscan), \nA. Razdobarin (SPbAU), and D. Dolmatov (SPbSU),\non behalf of the 239Alferov team, report:\n\nThe long-duration GRB 260121A \n(IPN triangulation: Kozyrev et al., GCN 43564;\nKonus-Wind detection: Ridnaia et al., GCN 43611)\nwas detected by 239Alferov 3U CubeSat at about 8552 s (02:22:32) UT.\n\nThe burst light curve, as measured by 239Alferov detector, shows \na single pulse with a duration of ~13 s. The emission is seen up to above ~1 MeV.\n\nThe light curve recorded by 239Alferov is available at:\nhttp://www.ioffe.ru/LEA/GRBs/GRB260121_T08549/239Alferov/\n\n239Alferov is an educational 3U CubeSat mission at SSO combining amateur radio \nand space research objectives. The gamma-ray detector onboard 239Alferov contains \na 64x72x15 mm NaI(Tl) scintillator read out by a SiPM array and covers the energy range \nfrom ~20 keV to ~1000 keV. The spacecraft is now at a commissioning stage, \nwith scientific observations started in December 2025. \nCurrently, the instrument records count rates in five energy bands:  \n~20-50 keV, ~50-100 keV, ~100-500 keV, 500-1000 keV, and > 1000 keV, with 1 s temporal resolution.\nThe surveys span a couple of days with about a day-long analysis and maintenance intervals \nbetween the observations.\nThe ground segment of the mission utilizes the SONIKS open ground station network.",
  "circularId": 43612,
  "submittedHow": "web",
  "format": "text/plain",
  "subject": "GRB 260121A: 239Alferov CubeSat detection"
}