TITLE:   GCN CIRCULAR
NUMBER:  25571
SUBJECT: LIGO/Virgo S190814bv: AT2019nqc and AT2019nqz 10.4m GTC spectroscopy
DATE:    19/08/30 10:44:26 GMT
FROM:    Alberto J. Castro-Tirado at IAA-CSIC  <ajct@iaa.es>

O. Lopez-Cruz (INAOE), A. J. Castro-Tirado (IAA-CSIC), L. Macri 
(TAMU),A. F. Valeev (SAO-RAS), E. Rios-Lopez (INAOE), Y.-D. Hu 
(IAA-CSIC), M. Diaz (UTRGV), E. Fernandez-Garcia (IAA-CSIC), E. Troja 
(UMD), A. Castellon (UMA), Chavushyan (INAOE), D. A. Kann 
(HETH/IAA-CSIC) and J. Font Serra (GRANTECAN, IAC,ULL), on behalf of 
three larger collaborations (including TOROS), report:

Following the detection of DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz 
(Andreoni et al., GCNC 25362) within the error area of the GW event 
S190814bv (LVC, GCNC 25324), we obtained imaging and optical spectra 
covering the range 3700-10000 A with the 10.4m GTC telescope equipped 
with OSIRIS at La Palma (Spain), on Aug 19 and Aug 21.

DG19ayfjc/AT2019nqz is located closer than 0.5 arcsec to the center of 
its host galaxy. On the stacked image with an exposure time of 3x10sec 
we could not detected the transient itself. From the emission lines of 
the host galaxy, a redshift z = 0.1076 +/- 0.0005 is measured, outside 
the expected LVC redshift range. The slit also covered the transient 
position, but no broad lines are detected.

DG19aqbkc/AT2019nqc spectroscopy reveals narrow galaxy lines at redshift 
  0.078 +/- 0.001. Cross-correlating the transient spectrum (broad lines) 
with supernova template spectra in SNID (Blondin & Tonry, 2007), we find 
a good match to the spectra of SNIIP at about week after maximum at same 
redshift, about a week after maximum at the same redshift in agreement 
with the result reported by Buckley et al. (GCNC 25481).

Therefore we consider both DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz
to be unrelated to the GW event S190814bv.

[GCN OPS NOTE(31aug19): In the first sentence, "DG19aqbkc/AT2019nqc"
was changed to "DG19qabkc/AT2019nqc".  In the last sentence,
"DG19aqbkc/AT2019nqc and DG19aqbkc/AT2019nqc" was changed to
"DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz".  We thank C. Balcon (ISSP)
for his comments.