GRB 240118A
GCN Circular 35607
Subject
GRB 240118A: Swift/UVOT Upper Limits
Date
2024-01-23T17:35:39Z (2 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
Via
Web form
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240118A
96191 s after the LAT trigger (Bissaldi et al., GCN Circ. 35560). No optical afterglow consistent with the
LAT position or the XRT position (Beardmore et al., GCN Circ. 35587) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u 96191 103639 3161 >20.8
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.056 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 35588
Subject
GRB 240118A: Mondy optical observations
Date
2024-01-20T23:54:29Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of IKI GRB FuN:
We observed the field of Fermi LAT localization of GRB 240118A (Bissaldi, GCN 35560), which was also detected by Fermi GBM (Fermi GBM team, GCN 35558; Hamburg, GCN 35563), NuSTAR (Grefenstette, GCN 35564), Konus-Wind (Frederiks, GCN 35567), Swift BAT (DeLaunay, GCN 35568), and GRBAlpha (Dafcikova et al., GCN 35580), and the localization area observed by MASTER-Tunka observatory (Lipunov et al., GCN 35561) and Abastumani observatory (Pankov et al., GCN 35572).
Observations started on 2024-01-18 (UT) 14:13:46 with AZT-33IK telescope of Sayan observatory (Mondy) in the R-filter. The observations have been carried out in moderate weather conditions with FWHM of 2.5". We report observations of XRT candidates detected in the Swift TOO program (Evans et al., GCN 35573).
XRT #1 - out of FOV
XRT #2 - matches bright USNO-B1.0 star with R2=9.98 mag
XRT #3 - within the XRT #3 error circle we detect a faint source, which matches SDSS J011408.49+294753.1 source with SDSS DR12 r'= 22.117 and redshift of z_phot = 0.68
XRT #4 - out of FOV
XRT #5 - matches bright Gaia DR3 star with G=6.48 mag
XRT #6 - out of FOV
XRT #7 - out of FOV
Preliminary photometry of the faint source XRT #3 suggested as an X-ray afterglow (Beardmore et al., GCN 35587