TITLE:   GCN CIRCULAR
NUMBER:  21703
SUBJECT: LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations of NGC4993
DATE:    17/08/25 22:15:33 GMT
FROM:    Aniello Grado at INAF-OAC  <aniello.grado@gmail.com>

A. Grado (INAF-OAC), F. Getman (INAF-OAC), L. Limatola (INAF-OAC), E.
Cappellaro (INAF-OAPD), M. Branchesi (GSSI), S. Covino
(INAF-OAB), P. D'Avanzo (INAF-OAB),  A. Melandri (INAF-OAB), L. Amati
(INAF-IASF Bo), L. A. Antonelli, (INAF-OAR), S. Ascenzi (INAF-OAR), S.
Benetti (INAF-OAPD), M.T. Botticella (INAF-OAC),  S. Campana (INAF-OAB), V.
D'Elia (INAF-ASDC), D. Fugazza, M. Lisi (INAF-OAR), G. Greco (Urbino
University/INFN Firenze), L. Nicastro (INAF-IASF Bo), E. Palazzi (INAF-IAFS
Bo), E. Pian (INAF-IASF Bo), S. Piranomonte (INAF-OAR), L. Pulone
(INAF-OAR), A. Rossi (INAF-IASF Bo), P. Schipani (INAF-OAC), G. Stratta
(Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB), V. Testa
(INAF-OAR), L . Tomasella (INAF-OAPD), S. Yang (INAF-OAPD), E. Brocato
(INAF-OAR) on behalf of GRavitational Wave Inaf TeAm report:


Observations of 1 square degrees of the skymap of the Advanced LIGO and
Virgo trigger G298048 (LVC GCN Circ. 21509, 21513) were performed with the
VLT Survey Telescope (VST - Proposal ID ESO 099.D-0191) at ESO-Paranal
equipped with OMEGACAM (FOV=1 square degree). The observations cover the
galaxy NGC4993.
The images were acquired with the g_SDSS, r_SDSS, i_SDSS, z_SDSS filters
for a total exposure of 200s in each filter. The observations started at
2017-08-22T 23:09:27.845 UTC and finished at 2017-08-23T 23:45:38.546 UTC.
The optical counterpart at RA=13:09:48.09 DEC=-23:22:53.35 reported by
Coulter et al. (LVC GCN 21529), Allam et al. (LVC GCN 21530), Yang et al.
(LVC GCN 21531), Melandri et al. (LVC GCN 21532) and several others authors
is visible in the gri filters with AB magnitudes of 23.3, 22.4 and 21.3
respectively, while is not visible in the z band.
Automatic data reduction with the VSTTube pipeline (Grado et al. 2012
Mem.SAIt 19, 362 ) was completed.
We acknowledge excellent support from the ESO User Support Department, in
particular G. Beccari, and from ESO observing staff in Paranal.