GCN Circular 44366
Subject
GRB 260421B: BOOTES-7 early optical afterglow detection
Event
Date
2026-04-21T05:37:53Z (2 days ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Via
email
S.-Y. Wu, M. Gritsevich, I. Perez-Garcia, E. Fernandez-Garcia, M. D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy, and A. J. Castro-Tirado (IAA-CSIC, Granada), C. Perez del Pulgar (Univ. of Malaga), Y.-D. Hu (GXU, Guanxi), B.-B. Zhang (Nanjing Univ.), and A. Maury (Space Obs., San Pedro de Atacama), on behalf of a larger collaboration, report:
Following the detection of GRB 260421B by Fermi (Fermi Team, GCN 44360, Preis and Greiner, GCN 44361) and SVOM (Zhao et al. GCN 44362), the BOOTES-7 telescope at the 0.6m BOOTES-7 robotic telescope at Space Observatory (San Pedro de Atacama, Chile) automatically observed the GRB location starting on Aug. 21, 04:28:36 UT (i.e. 15 min after GRB onset).
A series of images in clear filter were gathered and we identify the fading optical afterglow reported by He et al. (GCN 44363) Sánchez-Álvarez et al. (GCN 44364) and Turpin et al. (GCN 44365) at coordinates RA: 12:40:00.50 Dec: -17:44:24.0 (+/- 0.5 “). Preliminary magnitude is 18. Further data analysis is ongoing.
We would like to thank the staff at San Pedro de Atacama Space Observatory for their excellent support.