TITLE:   GCN CIRCULAR
NUMBER:  26764
SUBJECT: LIGO/Virgo S200114f: AT2020vr, AT2020vt, AT2020wa and AT2020wc 10.4m GTC spectroscopy
DATE:    20/01/15 09:28:38 GMT
FROM:    Alberto J. Castro-Tirado at IAA-CSIC  <ajct@iaa.es>

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

Following the detection of AT2020vr/ZTF20aafdytz, 
AT2020vt/ZTF20aafemum,  AT2020wa/ZTF20aafedbk, and AT2020wc/ZTF20aafeccu 
(Andreoni et al. GCNC 26741)  within the error area of the GW event 
S200114f (LVC, GCNC 26734), we obtained optical spectra covering the 
range 3700-7400 A with the 10.4m GTC telescope equipped with OSIRIS in 
La Palma (Spain) starting on Jan 15, 00:01 UT.

For AT2020vr/ZTF20aafdytz, we measure r= 19.80 +/- 0.02 on Jan 15, 00:08 
UT. The  GTC spectrum is consistent with a SN Ia at about 6 days before 
maximum at redshift z = 0.213 +/- 0.001, consistent with the redshift of 
the host galaxy derived from the emission lines (z= 0.2132 +/- 0.0005).

For AT2020vt/ZTF20aafemum, we measure r = 21.49 +/- 0.07 on Jan 15, 
01:19 UT. The GTC spectrum is consistent with a SN Ia at about 7 days 
before maximum at redshift z = 0.255 +/- 0.009, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.2528 
+/- 0.0005).

For AT2020wa/ZTF20aafedbk, we measure r = 19.50 +/- 0.03 on Jan 15, 
02:00 UT. The GTC spectrum is consistent with a SN Ia at about 4 days 
before maximum at redshift z = 0.077 +/- 0.010, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.0772 
+/- 0.0005).

For AT2020wc/ZTF20aafeccu, we measure r = 18.69 +/- 0.02 on Jan 15, 
02:11 UT. The GTC spectrum is consistent with a SN Ia at about 10 days 
before maximum at redshift z = 0.107+/- 0.009, consistent with the 
redshift of the host galaxy derived from the emission lines (z = 0.0983 
+/- 0.0005)

Therefore we consider that AT2020vr/ZTF20aafdytz, AT2020vt/ZTF20aafemum, 
AT2020wa/ZTF20aafedbk and AT2020wc/ZTF20aafeccu are unrelated to the 
S200114f GW alert.

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