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GCN Circular 34051

ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
2023-06-21T17:50:27Z (a year ago)
Anna Ridnaia at Ioffe Institute <>
A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

Konus-Wind (KW) was observing the whole sky between the last
GOTO non-detection (2023-06-17 23:50:30 UTC, hereafter T1; 
Gompertz at al., GCN Circ. 34023) and the first GOTO detection
(2023-06-18 01:27:41 UTC, hereafter T2; Gompertz at al., GCN Circ. 34023)
of ZTF23aaoohpy/AT2023lcr/ATLAS23msn (Swain et al., GCN Circ. 34022;
Tonry et al. TNS Astronomical Transient Report No. 180429).

No triggered or waiting-mode KW GRBs were detected during the
interval from T1 to T2. The closest waiting-mode GRBs were observed
~6.5 hours before T1 and ~2.3 hours after T2.

For the interval from T1 to T2, we estimate an upper limit (90% conf.)
on the 20 - 1500 keV fluence to 6.5x10^-7 erg/cm^2 for a burst lasting
less than 2.944 s and having a typical KW short GRB spectrum 
(an exponentially cut off power law with alpha =-0.5 and Ep=500 keV). 
For a typical long GRB spectrum (the Band function with alpha=-1, 
beta=-2.5, and Ep=300 keV), the corresponding limiting peak flux 
is 1.8x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale).

All the quoted values are preliminary.
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