GCN Circular 35077
Subject
GRB 231115A: optical observations from INAF observatories
Date
2023-11-17T13:48:03Z (6 months ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
Via
legacy email
P. D'Avanzo (INAF-OAB), A. Reguitti (INAF-OAB / INAF-OAPd), L. Tomasella (INAF-OAPd), E. Cappellaro (INAF-OAPd), M. T. Botticella (INAF-OAC), F. Onori (INAF-OAAb), L. Tartaglia (INAF-OAAb), F. De Luise (INAF OAAB), M. G. Bernardini (INAF-OAB), S. Campana (INAF-OAB), S. Covino (INAF-OAB), V. D'Elia (ASI/SSDC & INAF/OAR), M . De Pasquale (Univ. of Messina), D. B. Malesani (DAWN/NBI & Radboud Univ.), E. Palazzi (INAF-OAS), A. Rossi (INAF-OAS), R. Salvaterra (INAF-IASF Mi), G. Tagliaferri (INAF-OAB), A. Melandri (INAF-OAR), E. Brocato (INAF-OAAb), M. Pedani, C. P. Padilla-Torres (INAF/TNG) report on behalf ot the CIBO and of the GRAWITA collaborations:
We carried out follow-up optical observations of the high-energy event detected by Fermi/GBM, INTEGRAL, Glowbug, Insight-HMXT/HE, Konus-Wind, Swift/BAT on 2023-11-15 at 15:36:21 UT, initially classified as the short/hard GRB 231115A and subsequently as a likely magnetar giant flare located in the M82 galaxy (Fermi GBM team, GCN Circ. 35035; D'Avanzo et al., GCN Circ. 35036; Mereghetti et al., GCN Circ. 35037; Dalessi et al., GCN Circ. 35044; Cheung et al., GCN Circ. 35045; Xue et al. GCN Circ. 35060; Frederiks et al., GCN Circ. 35062; Ronchini et al., GCN Circ. 35065).
Observations from the INAF - Padova Astronomical Observatory located in Asiago (Italy) have been carried out with the Schmidt telescope starting on 2023-11-15 at 20:40:03 UT (~ 5 hours after the event T0) with the g, r and i filters.
Preliminary analysis, which includes image subtraction with SDSS templates, does not show evidence for promising candidate counterparts within the INTEGRAL error circle (Mereghetti et al., GCN Circ. 35037).
The typical 3sigma limiting AB magnitudes at the position of the candidate counterpart AT2023xfj (Kumar et al., GCN Circ. 35041 and 35055) are g ~ 19.5 mag, r ~ 18.4 mag and i ~ 20.3 mag.
Observations the from INAF - Abruzzo Astronomical Observatory located in Campo Imperatore (Italy) have been carried out starting on 2023-11-15 at 21:38:00 UT (~ 6 hours after the event T0) with the g, i and z filters.
Preliminary analysis, which includes image subtraction with SDSS templates, does not show evidence for promising candidate counterparts within the INTEGRAL error circle.
The typical 3sigma limiting AB magnitudes at the position of the candidate counterpart AT2023xfj are g ~ 18.7 mag, i ~ 17.2 mag and z ~ 17.2 mag.
Observations the from INAF - TNG located in Canary Islands (Spain) have have been carried out starting on 2023-11-16 at 03:27:28 UT (~ 12 hours after the event T0) with the r, i and z filters.
Preliminary analysis, which includes image subtraction with SDSS and archival TNG templates, does not show evidence for promising candidate counterparts within the INTEGRAL error circle.
The typical 3sigma limiting AB magnitude at the position of the candidate counterpart AT2023xfj in the r filter is of ~ 22.0 mag.