GCN Circular 42066

Subject

GRB 251002A: BOOTES-6 early optical detection

Event

GRB 251002A

Date

2025-10-02T23:27:43Z (6 days ago)

From

I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg@iaa.es>

Via

Web form

I. Perez-Garcia, S.-Y. Wu, E. Fernandez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, South Africa), A. Martin-Carrillo and L. Hanlon (UCD, Ireland), M. Gritsevich (Univ. of Helsinki) and C. J. Perez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report:

Following the detection of GRB 251002A by SVOM (Saccardi et al., GCN 42060

), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) responded to this high-energy event starting on Oct 2, 20:17:55 UT (i.e., 186 sec after detection). Series of images in clear filter were gathered and we detect an optical source consistent with the one reported by Palmerio et al. (GCN ), Turpin et al. (GCN ), Jelinek et al. (GCN ), Juliá-Maroto et al. (GCN ) and Moskvitin et al. (GCN ). Using GaiaDR3 Gmag as reference we report our photometry analysis:

UT mid exposure	mag	error	filter	exposure time (sec)
2025-10-02 20:18:25	15.47	0.03	clear	60
2025-10-02 20:19:53	15.79	0.03	clear	60
2025-10-02 20:21:21	16.16	0.05	clear	60

Further analysis of the additional images is ongoing.

We thank the staff at Boyden Observatory for their excellent support.