GCN Circular 26197

A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

Konus-Wind (KW) was observing the whole sky during a day before
discovery of ZTF19abvizsw (2019-09-02 04:19:12 UTC;
Kool et al., GCN Circ. 25616
Not found
 
 
) including the time of TESS detection
(2019-09-02 03:15 UTC, hereafter T0; Fausnaugh et al., GCN Circ. 25982
Not found
 
 
)

One triggered and one waiting-mode KW events were detected during
~1-day interval before T0. The burst localizations are inconsistent
with the ZTF19abvizsw.

For the interval excluding the KW events, we estimate
an upper limit (90% conf.) on the 20 - 1500 keV fluence to
6.3x10^-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 1.3x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s 
scale).

Assuming the redshift z=1.26 (Burdge et al. GCN circ. 25639
Not found
 
 
)
and a standard cosmology model with H_0 = 67.3 km/s/Mpc,
Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate an upper limit on a long GRB peak luminosity L_iso ~
1.3x10^51 erg/s.

All the quoted values are preliminary.