GCN Circular 25487

Adam Stewart (University of Sydney), Dougal Dobie (University of Sydney/CSIRO),
Tara Murphy (University of Sydney), Emil Lenc (CSIRO), Ziteng Wang
(University of Sydney), David Kaplan (UWM), Aidan Hotan (CSIRO),
Vanessa Moss (CSIRO) and the OzGrav, JAGWAR and GROWTH collaborations.

We report the discovery of a rising radio source detected with the Australian
Square Kilometre Array Pathfinder (ASKAP) within the 95% localisation volume
of S190814bv (GCN 25324
Not found
 
 
). The observations were conducted at a frequency of
943 MHz on 2019-08-16 and 2019-08-23 (see GCN 25445
Not found
 
 
 and GCN 25472
Not found
 
 
 for details).

We searched for sources with a rising flux density between the two observations
that are spatially coincident with known galaxies selected from the GLADE
catalogue (D��lya et al. 2018). One candidate is ASKAP 005547-270433, reported
as AT2019osy
Not found
 
 
 on the Transient Name Server, at
    RA = 00:55:47,
    Dec = -27:04:33,
offset ~1 arcsecond from 2dFGRS TGS211Z177.

ASKAP 005547-270433 has a 943 MHz integrated flux density of 376 +/- 33 uJy
in epoch 1 and 550 +/- 34 uJy in epoch 2. The redshift of 2dFGRS TGS211Z177
is 0.0738, which is consistent with the luminosity distance of S190814bv
(270+/-50 Mpc, GCN 25324
Not found
 
 
).

Further analysis of these ASKAP observations are ongoing and future
epochs are planned.

Thank you to CSIRO staff for supporting these observations.