TITLE:   GCN CIRCULAR
NUMBER:  25478
SUBJECT: LIGO/Virgo S190814bv: Keck II NIRES classification of DG19wxnjc/AT2019npv as a stripped envelope supernova
DATE:    19/08/26 06:52:50 GMT
FROM:    Kishalay De at Caltech, GROWTH  <kde@astro.caltech.edu>

K. De, J. Jencson, M. M. Kasliwal, D. Goldstein, I. Andreoni (Caltech)
report on behalf of the GROWTH (Global Relay of Observatories Watching
Transients Happen) collaboration

We further optimized the reduction of the Keck II NIRES spectrum of
DG19wxnjc/AT2019npv (Goldstein et al. GCN 25393) reported earlier in
De et al. GCN 25461. With better telluric correction, the He I 10830
line reported in our previous GCN is now more clearly identifiable
with a P-Cygni profile at z=0.056 (Jonker et al. GCN 25454) and
velocity of approximately 9000 km/s. This would be consistent with a
stripped envelope supernova and thus, unrelated to LIGO/Virgo
S190814bv (LVC et al. GCN 25324, GCN 25333). However, the observed
faint luminosity of -15.75 mag (Annis et al. GCN 25458) suggests there
could have been a brighter peak before discovery.

We are grateful to the W. M. Keck Observatory staff, especially Greg
Doppmann and Terry Stickel, for facilitating this partnership target
of opportunity observation. We thank the observer Leslie Young for her
kind co-operation.