GCN Circular 15696
Subject
GRB 140105A: continued iPTF observations and rejection of optical candidates
Date
2014-01-07T06:03:23Z (11 years ago)
From
Leo Singer at CIT/PTF <lsinger@caltech.edu>
L. P. Singer (Caltech), M. M. Kasliwal (Carnegie Observatories/Princeton),
S. B. Cenko (NASA/GSFC), E. Bellm (Caltech), and Y. Cao (Caltech) report
on behalf of the intermediate Palomar Transient Factory (iPTF)
collaboration:
We have continued to observe four optical transients (Singer et al.,
GCN 15686) in the Fermi GBM error circle for GRB 140105A (Xiong &
Connaughton, GCN 15688) with the Palomar 48-inch Oschin telescope
(P48), the robotic Palomar 60-inch (P60), and the Palomar 200-inch
(P200) equipped with the Double Beam Spectrograph (DBSP).
At 33 hours after the burst, with the P48 we obtain the following
host-subtracted magnitudes in the Mould R filter:
iPTF14x, R = 20.0
iPTF14ac, R = 20.3
iPTF14ae, R = 20.5
With the P60, at 34 hours after the burst, we obtain the following
magnitude in the SDSS system:
iPTF14ai, r = 20.4
We obtained spectra of all four with the P200. iPTF14x resembles a
Type II supernova. Our spectra for iPTF14ac, iPTF14ae, and iPTF14ai
show a mostly featureless continuum.
The lack of significant optical fading in any of the four candidates
strongly argues against association with the GRB.