TITLE: GCN CIRCULAR NUMBER: 38654 SUBJECT: GRB 241105A: JWST photometric observations of the host galaxy DATE: 24/12/23 18:01:25 GMT FROM: Dimple at University of Birmingham <dimplepanchal96@gmail.com> Dimple (U. Birmingham), B. P. Gompertz (U. Birmingham), A. J. Levan (Radboud Univ. and Warwick Univ.), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Martin-Carrillo (UCD), M. E. Ravasio (Radboud Univ.), L. Izzo (INAF/OACn & DARK/NBI), Andrea Rossi (INAF/OAS), P. D'Avanzo (INAF/OABr), N. R. Tanvir (U. Leicester) on behalf of a larger collaboration: We conducted photometric observations of the GRB 241105A field (Fermi GBM team, GCN 38085; DeLaunay et al., GCN 38091; Frederiks et al., GCN 38103; Julakanti et al., GCN 38088; Izzo et al., GCN 38097; SVOM/VT team, GCN 38099; Hu et al., GCN 38106) at a redshift of z = 2.681 (Izzo et al., GCN 38167) using the James Webb Space Telescope (JWST; DDT program 9228, PI: Dimple). These observations, carried out with the NIRCam instrument in multiple bands (F070W, F115W, F150W, F277W, F356W, F444W), began on 2024-12-22 at 17:26 UT, approximately 47 days after the trigger (~12.7 days in the GRB rest frame). The bright galaxy identified in archival images (Julakanti et al., GCN 38088) is well detected in all observed bands, and is resolved into at least two bright, extended spots about 0.2" apart. The afterglow position is within 0.06" of the NE spot centroid (about 500 pc in projection at z = 2.681). The NE patch has a magnitude of F277W(AB) = 22.54±0.03. This is significantly brighter than a SN akin to SN 1998bw at z = 2.681, which would peak at magnitude ~26.3 In the same filter, making it hard to determine the contribution from an underlying SN, should any be present. Subtraction of the galaxy's contribution, which will be possible with late-time imaging, will help to single out any transient emission. We acknowledge the support from Weston Eck and Armin Rest (STScI) in preparing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/38654. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...