TITLE:   GCN CIRCULAR
NUMBER:  20426
SUBJECT: LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
DATE:    17/01/11 14:51:16 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <pda.davanzo@gmail.com>

A. Giunta, A. Di Paola, M. Centrone, N. Napoleone, P. Tedesco (INAF-OAR), S. Covino, P. D'Avanzo, A. Melandri (INAF-OAB), L. Amati (INAF-IASF Bo), L. A. Antonelli, (INAF-OAR), S. Ascenzi (INAF-OAR), M.T. Botticella (INAF-OAC),  M. Branchesi (Urbino University/INFN Firenze), S. Campana (INAF-OAB), E. Cappellaro (INAF-OAPD), V. D'Elia (INAF-ASDC), F. Getman (INAF-OAC), A. Grado (INAF-OAC), G. Greco (Urbino University/INFN Firenze), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), L. Nicastro (INAF-IASF Bo), E. Palazzi (INAF-IAFS Bo), E. Pian (SNS-Pisa), S. Piranomonte (INAF-OAR), L. Pulone (INAF-OAR), A. Rossi (INAF-IASF Bo), 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:


We carried out observations of LIGO/Virgo G268556 (LVC, GCN 20364) with the 0.9m Schmidt telesope located at the Campo Imperatore Observatory (Italy). The observations were taken in the r-sloan band on 2017-01-04 between 18:49:58 UT and 20:31:15 UT (8.6-10.3 hours after the trigger) under poor sky conditions. 
The covered area of ~ 6 square degrees captured a containment probability of ~1% of the LALInference map (LVC, GCN 20385). The area is divided in 5 pointings of 1.15x1.15 degrees and 120 sec exptime each. The pointing sequence was generated using the GWsky script (https://github.com/ggreco77/GWsky) starting from the high probability region of the bayestar skymap and taking into account the airmass.

The 5 pointings are centered on the following coordinates RA, Dec (J2000):
131.6290   +47.8526
131.6304   +48.8528
132.9895   +47.8364
132.9902   +48.8390
132.9896   +49.8408

A preliminary analysis of these data reveals no obvious candidate counterpart down to a 3sigma limiting magnitude r ~ 17.0 (AB, calibrated against the SDSS DR13).