TITLE: GCN CIRCULAR NUMBER: 20669 SUBJECT: LIGO/Virgo G270580: DLT40 follow-up observation DATE: 17/02/13 19:20:20 GMT FROM: Sheng Yang at UC Davis Sheng Yang (INAF-OAPd, UC Davis), Stefano Valenti(UC Davis), David Sand (TTU), Leonardo Tartaglia (TTU, UC Davis), Enrico Cappellaro (INAF-OAPd), Dan Reichart, Josh Haislip (UNC) report on behalf of the Gravitational Wave Follow-Up by DLT40. We report the observation of 25 galaxies within the LVC error region for the GW trigger G270580 using the 'bayestar' GW localization map. We selected 33 galaxies from the GWGC catalogue within 99% of the trigger error region, within a distance of 20 Mpc, brighter that -17.5 mag and at a Declination < 20 degree. 25 of those galaxies have been observed using the Prompt 5 telescope and are part of the ongoing DLT40 search. They represent the 1.33% of all galaxies within 20 Mpc in the Glade catalogue within the LVC error region for the GW trigger and contains 5% of all B band luminosity of those galaxies. We started to observe these sample of galaxies on 2017-01-23 and monitored them for 3 weeks after the GW trigger. No interesting transients have been identified down to a limit magnitude of 19.2. Below follow the list of galaxies observed: Name RA(J2000) DEC(J2000) Dist(Mpc) BMAG KMAG NGC0428 18.2317 0.9817 14.79 -19.12 -21.4648 NGC1249 47.505 -53.3359 14.19 -19.16 -21.4059 IC1954 52.8808 -51.9049 13.68 -18.98 -21.9344 NGC1546 63.6519 -56.0609 13.87 -18.21 -22.6574 IC2056 64.1022 -60.2068 15.0 -18.48 -21.7285 NGC1559 64.3989 -62.7836 12.59 -19.85 -22.4821 NGC1566 65.0016 -54.9378 6.55 -18.89 -22.1952 NGC1602 66.979 -55.0578 13.69 -18.48 -18.663 NGC1617 67.9156 -54.6019 13.87 -19.79 -23.6334 NGC1796 75.6777 -61.1399 15.0 -18.28 -21.1815 NGC1947 81.6979 -63.7613 13.87 -19.01 -23.2134 PGC018855 95.2321 -8.4956 11.22 -18.39 -21.937 NGC2283 101.4718 -18.2122 9.86 -18.17 -19.8484 ESO494-026 121.546 -27.528 14.15 -19.86 -22.8778 NGC2640 129.3526 -55.1237 12.71 -20.17 -23.8057 NGC2784 138.0813 -24.1725 9.82 -19.42 -23.6386 NGC2835 139.4703 -22.3546 8.05 -19.03 -21.612 NGC3521 166.4524 -0.0358 11.22 -20.85 -24.467 NGC4123 182.0463 2.8782 14.86 -19.09 -22.0681 NGC4178 183.1929 10.8658 14.0 -19.37 -21.1556 NGC4192 183.4513 14.8993 13.61 -20.62 -23.7813 NGC4216 183.9762 13.15 14.13 -20.58 -24.2267 NGC4419 186.7357 15.047 13.49 -19.24 -22.9131 NGC4498 187.9144 16.852 14.06 -18.54 -21.0799 NGC4571 189.2349 14.2173 14.93 -19.12 -22.3523