TITLE: GCN CIRCULAR NUMBER: 18786 SUBJECT: LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30 DATE: 15/12/31 17:38:41 GMT FROM: S. J. Smartt at Queens U Belfast K. Smith, S. Smartt D. Wright, (Queen’s University Belfast), K. C. Chambers, M. E. Huber, A. S. B. Schultz (IfA, University of Hawaii), M. Coughlin (Harvard), L. Denneau, H. Flewelling, A. Heinze, R. Kotak (QUB), E. A. Magnier, N. Primak, A. Rest (STScI), A. Sherstyuk (IfA), B. Stalder (IfA), C. W. Stubbs (Harvard), J. Tonry, C. Waters (IfA), D. Young (QUB) Following our report of Pan-STARRS observations of the northern arc, (Chambers et al. GCN 18735), we report the following transients. All objects were identified in difference imaging with respect to the Pan-STARRS 3Pi all sky i-band image (see Magnier et al. 2013, ApJS 205, 20 ; Huber et al. 2015, ATel 7153) and standard filtering procedures combined with machine learning (Wright et al. 2015, MNRAS, 449, 451). We have removed obvious moving objects, variable star and AGN/QSO candidates as far as possible through cross-matching with known catalogues and the MPC. Further refined cross-matches are noted below. The rest are transients which are not obviously associated with a single star or a galaxy core. All magnitudes are in the Pan-STARRS i-band (AB mags), and the discovery date is UTC. Targets are sorted by time of discovery. Approximately 10-15 of the brighter targets are queued for observing with Gemini, Magellan, PESSTO, and the Liverpool Telescope. Pan-STARRS has observed the field as noted in (Chambers et al. GCN 18735) on three nights from (20151228, 20151229, 20151230) and plans another 5 epochs between now and 2016 01 25. Some more specific notes (1) this was reported as iPTF15fgy Cenko et al. (GCN 18762) but we have a detection 24 days previously on 57360 by PSST (Huber et al. 2015). (2) discovered as PSNJ02344555+1820390 before the G211117 trigger (3) Lipunov et al. (GCN 18768) report iPTF15fel as being visible in MASTER images more than 40 days before the G211117 trigger (4) Faint transient, or more likely variable, in NGC1156 which is a very nearby galaxy (7Mpc). At M_i = -9, this is most likely an LBV or S-Doradus type variability of a massive star and indeed the candidate is coincident with a bright, stellar knot. We welcome notification of other cross-matches that we may have omitted, or duplications that we may have missed. Name RA (J2000) Dec (J2000) Disc. Date Disc. MJD Disc Mag PS15dcq 03 22 55.83 +34 59 23.6 20151228.29 57384.29 19.99 (1) iPTF15fgy PS15dov 03 43 57.36 +39 17 43.7 20151228.32 57384.32 19.73 4.2” from SN2003ih PS15dot 02 11 55.69 +13 28 17.8 20151228.34 57384.34 20.97 PS15coh 02 15 58.45 +12 14 13.6 20151228.34 57384.34 17.72 ASASSN-15rw, iPTF15fev PS15dow 02 19 42.20 +14 09 54.7 20151228.34 57384.34 20.22 PS15csf 02 26 02.24 +17 03 40.4 20151228.35 57384.35 18.68 MASTER OT J022037.36+170217.5 PS15dom 02 34 45.62 +18 20 37.7 20151228.35 57384.35 19.01 (2) PSNJ02344555+1820390, iPTF15fdv PS15don 02 37 11.44 +19 03 20.2 20151228.35 57384.35 20.47 PS15dox 02 40 15.05 +22 32 12.1 20151228.38 57384.38 19.23 PS15doy 02 47 54.16 +21 46 24.0 20151228.38 57384.38 20.75 PS15dpq 03 09 12.74 +27 31 16.9 20151228.39 57384.39 18.84 (3) iPTF15fel PS15dpa 02 57 56.02 +28 53 37.1 20151228.40 57384.40 19.51 PS15dpp 03 00 39.86 +28 15 25.4 20151228.40 57384.40 20.63 likely stellar PS15dop 03 17 29.58 +29 34 09.2 20151228.40 57384.40 20.01 probable AGN PS15dpe 05 44 42.66 +52 24 57.9 20151228.43 57384.43 19.44 PS15dpl 05 47 45.39 +53 36 32.4 20151228.43 57384.43 19.34 PS15dpj 05 08 12.38 +51 37 10.2 20151228.44 57384.44 18.45 PS15dpd 05 09 58.63 +50 47 09.4 20151228.44 57384.44 20.34 PS15dpi 03 36 41.65 +35 57 56.4 20151228.52 57384.52 17.62 RR Lyrae; CSS J033641.5+355756 PS15dpn 02 32 59.75 +18 38 07.0 20151229.23 57385.23 20.69 PS15dpf 02 49 32.57 +21 47 09.4 20151229.24 57385.24 20.69 PS15doz 02 53 41.68 +27 29 57.8 20151229.25 57385.25 20.69 PS15dpo 02 59 49.56 +25 10 30.4 20151229.25 57385.25 20.55 probable AGN/QSO PS15dpc 03 55 46.16 +38 52 49.6 20151229.27 57385.27 20.95 PS15dqc 05 51 13.43 +52 28 18.7 20151229.29 57385.29 21.16 PS15dpz 02 40 33.01 +23 00 10.8 20151229.32 57385.32 21.15 PS15dpb 03 42 23.40 +39 14 40.4 20151229.36 57385.36 20.20 PS15dpk 05 09 35.10 +50 09 08.7 20151229.38 57385.38 19.66 PS15dpg 03 17 18.88 +32 20 06.9 20151229.41 57385.41 20.86 PS15dps 03 22 31.49 +34 36 36.6 20151229.43 57385.43 20.41 PS15dpr 03 16 12.16 +31 04 01.3 20151229.46 57385.46 19.78 PS15dph 03 24 15.04 +30 56 20.1 20151229.46 57385.46 20.17 PS15dou 06 03 38.73 +54 41 12.1 20151229.56 57385.56 20.20 PS15dpx 06 04 35.54 +53 35 25.8 20151229.56 57385.56 20.76 PS15dpm 06 19 54.15 +54 18 10.3 20151229.56 57385.56 20.48 PS15dpt 02 07 34.96 +11 03 25.2 20151230.22 57386.22 20.64 PS15dpy 02 28 22.75 +13 59 19.3 20151230.22 57386.22 21.31 PS15dpu 02 40 41.35 +16 49 52.0 20151230.22 57386.22 17.26 ASASSN-15un PS15dqa 02 59 41.20 +25 14 12.2 20151230.24 57386.24 20.93 (4) in NGC1156 (7Mpc) PS15dpw 04 10 16.52 +43 35 22.8 20151230.27 57386.27 19.29 PS15dqd 05 56 14.60 +52 51 55.2 20151230.37 57386.37 19.92 PS15dqe 06 05 26.88 +54 09 11.3 20151230.37 57386.37 21.51 PS15dqb 03 28 34.85 +31 59 08.2 20151230.43 57386.43 19.93 PS15dpv 03 40 02.91 +36 07 52.2 20151230.43 57386.43 20.93