Abbott, B. P.B. P.AbbottAbbott, R.R.AbbottAbbott, T. D.T. D.AbbottAbernathy, M. R.M. R.AbernathyAcernese, F.F.AcerneseAckley, K.K.AckleyAdams, C.C.AdamsAdams, T.T.AdamsAddesso, P.P.AddessoAdhikari, R. X.R. X.AdhikariAdya, V. B.V. B.AdyaAffeldt, C.C.AffeldtAgathos, M.M.AgathosAgatsuma, K.K.AgatsumaAggarwal, N.N.AggarwalAguiar, O. D.O. D.AguiarAiello, L.L.AielloAin, A.A.AinAjith, P.P.AjithAllen, B.B.AllenAllocca, A.A.AlloccaAltin, P. A.P. A.AltinAnderson, S. B.S. B.AndersonAnderson, W. G.W. G.AndersonArai, K.K.AraiAraya, M. C.M. C.ArayaArceneaux, C. C.C. C.ArceneauxAreeda, J. S.J. S.AreedaArnaud, N.N.ArnaudArun, K. G.K. G.ArunAscenzi, S.S.AscenziAshton, G.G.AshtonAst, M.M.AstAston, S. M.S. M.AstonAstone, P.P.AstoneAufmuth, P.P.AufmuthAulbert, C.C.AulbertBabak, S.S.BabakBacon, P.P.BaconBader, M. K.M.M. K.M.BaderBaker, P. T.P. T.BakerBaldaccini, F.F.BaldacciniBallardin, G.G.BallardinBallmer, S. W.S. W.BallmerBarayoga, J. C.J. C.BarayogaBarclay, S. E.S. E.BarclayBarish, B. C.B. C.BarishBarker, D.D.BarkerBarone, F.F.BaroneBarr, B.B.BarrBarsotti, L.L.BarsottiBarsuglia, M.M.BarsugliaBarta, D.D.BartaBarthelmy, S.S.BarthelmyBartlett, J.J.BartlettBartos, I.I.BartosBassiri, R.R.BassiriBasti, A.A.BastiBatch, J. C.J. C.BatchBaune, C.C.BauneBavigadda, V.V.BavigaddaBazzan, M.M.BazzanBehnke, B.B.BehnkeBejger, M.M.BejgerBell, A. S.A. S.BellBell, C. J.C. J.BellBerger, B. K.B. K.BergerBergman, J.J.BergmanBergmann, G.G.BergmannBerry, C. P.L.C. P.L.BerryBersanetti, D.D.BersanettiBertolini, A.A.BertoliniBetzwieser, J.J.BetzwieserBhagwat, S.S.BhagwatBhandare, R.R.BhandareBilenko, I. A.I. A.BilenkoBillingsley, G.G.BillingsleyBirch, J.J.BirchBirney, R.R.BirneyBiscans, S.S.BiscansBisht, A.A.BishtBitossi, M.M.BitossiBiwer, C.C.BiwerBizouard, M. A.M. A.BizouardBlackburn, J. K.J. K.BlackburnBlair, C. D.C. D.BlairBlair, D. G.D. G.BlairBlair, R. M.R. M.BlairBloemen, S.S.BloemenBock, O.O.BockBodiya, T. P.T. P.BodiyaBoer, M.M.BoerBogaert, G.G.BogaertBogan, C.C.BoganBohe, A.A.BoheBojtos, P.P.BojtosBond, C.C.BondBondu, F.F.BonduBonnand, R.R.BonnandBoom, B. A.B. A.Boom2025-08-302025-08-302016-07-0110.3847/0067-0049/225/1/82-s2.0-84982684987https://d8.irins.org/handle/IITG2025/21876This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands.truegravitational waves | methods: observationalArticlehttps://iopscience.iop.org/article/10.3847/0067-0049/225/1/8/pdf1 July 2016508arJournal44