[vsnet-grb-info 22115] LIGO/Virgo S190425z: ZTF19aarzaod 1.5m OSN imaging and 10.4m GTC spectroscopy

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24214
SUBJECT: LIGO/Virgo S190425z: ZTF19aarzaod 1.5m OSN imaging and 10.4m GTC spectroscopy
DATE:    19/04/26 06:32:04 GMT
FROM:    Alberto J. Castro-Tirado at IAA-CSIC  <ajct at iaa.es>

A. J. Castro-Tirado, Y.-D. Hu, X.-Y. Li, E. Fernandez-Garcia and V. 
Casanova (IAA-CSIC), A. F. Valeev and V. V. Sokolov (SAO-RAS), I. 
Carrasco, A. Castellon and C. Perez del Pulgar (UMA), M. D. 
Caballero-Garcia (ASU-CAS), S. B. Pandey (ARIES) and N. Castro-Rodriguez 
(GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report:

Following the report of the new transient ZTF19aarzaod (Kasliwal et al., 
GCN 24191) for the GW event S190425z (GCN 24168), we observed the target 
with the 1.5m telescope at the Observatorio de Sierra Nevada (Spain), 
measuring a R-band mag of 20.5 on Apr 26, 01:48 UT. An optical spectrum 
(600s) covering the range 3700-7500 A was obtained with the 10.4m GTC 
telescope equipped with OSIRIS in La Palma (Spain) on Apr 26, 03:40 UT. 
It shows a red continuum with a broad emission consistent with being 
H-alpha at the redshift of the host galaxy (z=0.0279) besides a narrow 
H-beta emission line at a consistent redshift. Therefore we rule out the 
relationship of ZTF19aarzaod to the GW event S190425z in agreement with 
Buckley et al. (GCN 24205), Izzo et al. (GCN 24208), Wiersema (GCN 
24209) and Nicholl et al. (GCN 24211).

We acknowledge the excellent support from the GTC staff.