J/A+A/705/A104ivo://CDS.VizieR/J/A+A/705/A104CDSPeng Z.-H.Benetti S.Cai Y.-Z.Pastorello A.Valerin G.Reguitti A.,Fiore A.Fang Q.-L.Wang Z.-Y.Berton M.Borsato L.Cappellaro E.,Congiu E.Elias-Rosa N.Granata V.Isern J.La Mura G.Ochner P.,Raddi R.Terreran G.Tomasella L.Turatto M.Yan S.-Y.Pei S.-P.,Wu C.-Y.Zha S.Wang X.-F.Wang B.Pan Y.2026-03-02T06:25:50Z2026-01-09T10:23:22ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsupernovaephotometryvisible-astronomyWe present optical photometric and spectroscopic observations of the rapidly declining Type IIL supernova (SN) 2016iog. SN 2016iog reached its peak ~14 days after explosion, with an absolute magnitude in the V band of -18.64+/-0.15mag, followed by a steep decline of 8.85+/-0.15mag(100d)^-1^ post-peak. Such a high decline rate makes SN 2016iog one of the fastest declining Type IIL SNe observed to date. The rapid rise in the light curve, combined with the nearly featureless continuum observed in the spectrum at +9.3days, suggests the presence of interaction.In the recombination phase, we observed broad Halpha lines that persist at all epochs. In addition, the prominent double-peaked Halpha feature observed in the late-time spectrum (+190.8days) is likely attributable either to significant dust formation within a cool dense shell or to asymmetric circumstellar material. These features suggest the presence of sustained interaction around SN 2016iog. We propose that the observed characteristics of SN 2016iog can be qualitatively explained by assuming a low-mass H-rich envelope surrounding a red supergiant progenitor star with low-density circumstellar material.2026A&A...705A.104Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/705/A104CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/705/A104https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/705/A104http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/705/A104https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/705/A104https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/705/A104http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/705/A104GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/705/A104/16iogThe multi-band photometric data for SN 2016iogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of observation (yymmdd)'Y:M:D'time.epochnullableMJDModified Julian Datedtime.epochdoubleFilterFilter (BV G ugriz orange cyan)meta.id;instr.filtercharSystemAB or Vegameta.notecharmagApparent magnitudemagphot.magfloate_magError on apparent magnitudemagstat.error;phot.magfloatl_mag[UP] 'U' for limit and 'P' for detectionmeta.code.errorcharInst/SourceInstrument or Sourcemeta.id;instrchar