GCN Circular 37252
Subject
SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
Date
2024-08-23T23:42:18Z (4 months ago)
From
Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it>
Via
Web form
S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez (Montarrenti Observatory, Siena, Italy, part of UAI/SSV-GRB section), M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy) and B. De Simone (Università degli Studi Di Salerno) report:
We performed follow-up observations of the field of the soft gamma ray repeater SGR 1E 1841-045 / Kes 73 in two distinct epochs with the automated and remoted 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88).
Observations of the first epoch were started at 2024-08-20 20:10:54 UT, after twilight, approximately 1 hour after burst (Swift trigger 1249653, GCN 37211 DeLaunay et al.; Fermi-GBM, GCN 37234 Roberts et al.).
Observations of the second epoch were started at 2024-08-21 20:06:04 UT, serendipitously covering a burst activity (Swift trigger 1249878, GCN 37222 Dichiara et al.; Fermi-GBM, GCN 37234 Roberts et al.; GECAM-B, GCN 37240 Zhang et al.).
The field is very crowded. In our preliminary analysis, we have not found any optical transient candidate within the error-box (3 arcmin.) of the Neil Gehrels Swift Observatory position (Epoch 1, RA 18h 41m 21s, Dec. -04d 55m 39s; Epoch 2, RA 18h 41m 22s, Dec. -04d 57m 00s - J2000) down to the following 3-sigma optical upper limits:
Epoch MJD Exp. Filter UL (3-sigma)
1 60543.3629 87x40s Rc > 20.0
2 60544.3576 61x40s Rc > 20.1
Magnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations. No correction for galactic dust extinction was applied.