TITLE:   GCN CIRCULAR
NUMBER:  39273
SUBJECT: LIGO/VIRGO/KAGRA S250206dm: AT 2025bbo spectroscopic observations with NIRES on Keck II
DATE:    25/02/11 01:04:26 GMT
FROM:    Viraj Karambelkar at Indian Inst of Tech,Bombay <karambelkarvraj21197@gmail.com>

Viraj Karambelkar (Caltech), Tomas Ahumada (Caltech), Sam Rose (Caltech),
Kaew Tinyanont (NARIT), Christoffer Fremling (Caltech), Nicholas Earley
(Caltech),  and Mansi Kasliwal (Caltech) report:

We observed the transient AT2025bbo (GCN 39210; 39244) with the
Near-Infrared Echelle Spectrograph (NIRES, Wilson et al. 2004) on the Keck
II telescope on  2025-02-10 05:29:43 UTC. Our observations comprised six
exposures of 300s each. The spectra were extracted using the idl package
spextool (Cushing et al. 2003, Vacca et al. 2004)

The spectrum shows several absorption features attributable to the host
galaxy (CN, Mg I, Si I, CO absorption) at a redshift of z=0.070+/-0.001,
consistent with the redshift reported in GCN 39272. No obvious features
attributable to a supernova or AGN are visible. Further analysis is in
progress.

We thank the Keck Observatory staff (Carlos Alvarez and Rita) and the Keck
II observers (Maissa Salama and Becky Jensen-Clem) for their cooperation
with the Target of Opportunity observations.