J/ApJ/861/63ivo://CDS.VizieR/J/ApJ/861/63doi:10.26093/cds/vizier.18610063CDSHosseinzadeh G.Valenti S.McCully C.Howell D.A.Arcavi I.,Jerkstrand A.Guevel D.Tartaglia L.Rui L.Mo J.Wang X.Huang F.,Song H.Zhang T.Itagaki K.2020-04-27T13:08:21Z2019-08-06T13:26:24ZCDS support team

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

cds-question@unistra.frsupernovaeinfrared-photometryvisible-astronomybroad-band-photometryspectroscopyWhile interaction with circumstellar material is known to play an important role in Type IIn supernovae (SNe), analyses of the more common SNe IIP and IIL have not traditionally included interaction as a significant power source. However, recent campaigns to observe SNe within days of explosion have revealed narrow emission lines of high-ionization species in the earliest spectra of luminous SNe II of all subclasses. These "flash ionization" features indicate the presence of a confined shell of material around the progenitor star. Here we present the first low-luminosity (LL) SN to show flash ionization features, SN 2016bkv. This SN peaked at MV = -16 mag and has H{alpha} expansion velocities under 1350 km s-1 around maximum light, placing it at the faint/slow end of the distribution of SNe IIP (similar to SN 2005cs). The light-curve shape of SN 2016bkv is also extreme among SNe IIP. A very strong initial peak could indicate additional luminosity from circumstellar interaction. A very small fall from the plateau to the nickel tail indicates unusually large production of radioactive nickel compared to other LL SNe IIP. A comparison between nebular spectra of SN 2016bkv and models raises the possibility that SN 2016bkv is an electron-capture supernova.2018ApJ...861...63Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/861/63CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/183 : UBVRI Photometric Standards (Landolt 1992)II/282 : The SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)J/ApJ/736/159 : Photometry monitoring of the SN PTF10vdl (Gal-Yam+, 2011)J/MNRAS/442/844 : BVRI light curves of type II-P supernovae (Faran+, 2014)J/MNRAS/459/3939 : Type II supernova light curves (Valenti+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/861/63https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/861/63http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/861/63https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/861/63https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/861/63http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/861/63GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapAssociated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/ApJ/861/63OpticalInfrareddefaultJ/ApJ/861/63/fig1One year of photometry of SN 2016bkvrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[57468.7/57918.2] Modified Julian Date of observationdtime.epochdoubleFilt[0UBVRIgri] Filter used (0: unfiltered KAF-1001E CCD)instr.setup;instr.filtercharmag[13.3/24.3] Apparent magnitude in Filtmagphot.magfloate_mag[0.01/8.4] Uncertainty in magmagstat.error;phot.magfloatObsObservatory code for mag (1)meta.codecharJ/ApJ/861/63/table1Log of spectroscopic observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[57470.5/58075.6] Modified Julian Date of observationdtime.epochfloatTelTelescopemeta.id;instr.telcharInstInstrumentmeta.id;instrcharPhase[3/606.9] Phasedtime.phasefloatFileFile name in subdirectory sp/ -- column added by CDSmeta.id;meta.filecharSpInteractive spectrum plotmeta.ref.urlchar