TITLE:   GCN CIRCULAR
NUMBER:  25598
SUBJECT: LIGO/Virgo S190814bv: LCO Photometry of desgw-190814f/AT2019nte
DATE:    19/09/01 20:57:09 GMT
FROM:    Shreya Anand at GROWTH Caltech  <sanand@caltech.edu>

Shreya Anand, Michael Coughlin, Igor Andreoni, and Tomas Ahumada report on behalf of Global Relay of Observatories Watching Transients Happen (GROWTH):


We observed the nuclear transient desgw-190814f/AT2019nte, (Herner et al. GCN 25398) with the Siding Springs 2m Spectral imager of Las Cumbres Observatory (LCO) on 2019-08-22 and on 2019-08-27 in the g, r, and i-bands.  To perform image subtraction, we used references from the DECam Legacy Survey (DECaLS) and the Dark Energy Survey (DES).  The transient is not detected in g-band on either night to an upper limit of 20.3 mag.  We show our photometry in g-, r-, and i-bands below:


| UT dateobs | g mag | r mag | i mag |

| 2019-08-22 | > 20.3 | 23.3 +/- 0.23 | > 21.0 |

| 2019-08-27 | > 20.3 | 23.0 +/- 0.07 | 22.28 +/- 0.30 |


Our measurements show a slow rise in the i-band for desgw-190814f, while the r-band measurements may be consistent with no evolution to within the uncertainties.  We note that this transient host galaxy has a spectroscopic redshift from the 2dF survey (z~0.07) that is consistent with the LIGO/Virgo localization.


We encourage further monitoring of this transient.