J/MNRAS/493/1761ivo://CDS.VizieR/J/MNRAS/493/1761doi:10.26093/cds/vizier.74931761CDSReynolds T.M.Fraser M.Mattila S.Ergon M.Dessart L.Lundqvist P.,Dong S.Elias-Rosa N.Galbany L.Gutierrez C.P.Kangas T.Kankare E.,Kotak R.Kuncarayakti H.Pastorello A.Rodriguez O.Smartt S.J.,Stritzinger M.Tomasella L.Chen P.Harmanen J.Hosseinzadeh G.,Howell D.A.Inserra C.Nicholl M.Nielsen M.Smith K.Somero A.,Tronsgaard R.Young D.R.2024-08-20T20:16:12Z2023-07-05T13:57:23ZCDS support team

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

cds-question@unistra.frsupernovaeinfrared-photometryvisible-astronomybroad-band-photometryWe present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V=-19.95+/-0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in H{alpha} are also unusually high with the blue edge tracing the fastest moving gas initially at 20000km/s, and then declining approximately linearly to 15000km/s over ~100d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the JEKYLL code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H{alpha} absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry.2020MNRAS.493.1761Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/493/1761CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/493/1761https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/493/1761http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/493/1761https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/493/1761https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/493/1761http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/493/1761GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/493/1761/tablea1 (Magnitudes for the calibration stars shown in Fig. 1.)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/493/1761/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/493/1761/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/493/1761/tablea1?GETtext/xml+votable180.050000true40.114719.208810.0055555555555555566/6027.952274030004205e-20 6.090060298487514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/493/1761?format=asciiOpticalInfrareddefaultJ/MNRAS/493/1761/tablea1Magnitudes for the calibration stars shown in Fig. 1.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/20] Star internal identifiermeta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainUmag? U-band magnitude from the SCUSS survey (G1)magphot.mag;em.opt.Ufloatnullablee_Umag? Error on Umagmagstat.error;phot.magfloatnullableBmagB-band magnitude converted from Pan-STARRS1 (G1)magphot.mag;em.opt.Bfloate_BmagError on Bmagmagstat.error;phot.magfloatVmagV-band magnitude converted from Pan-STARRS1 (G1)magphot.mag;em.opt.Vfloate_VmagError on Vmagmagstat.error;phot.magfloatRmagR-band magnitude converted from Pan-STARRS1 (G1)magphot.mag;em.opt.Rfloate_RmagError on Rmagmagstat.error;phot.magfloatImagI-band magnitude converted from Pan-STARRS1 (G1)magphot.mag;em.opt.Ifloate_ImagError on Imagmagstat.error;phot.magfloatumag? SDSS u-band magnitude (G2)magphot.mag;em.opt.Ufloatnullablee_umag? Error on umagmagstat.error;phot.magfloatnullablegmagSloan g-band magnitude (G2)magphot.mag;em.opt.Bfloate_gmagError on gmagmagstat.error;phot.magfloatrmagSloan r-band magnitude (G2)magphot.mag;em.opt.Rfloate_rmagError on rmagmagstat.error;phot.magfloatimagSloan i-band magnitude (G2)magphot.mag;em.opt.Ifloate_imagError on imagmagstat.error;phot.magfloatzmagSloan z-band magnitude (G2)magphot.mag;em.opt.Ifloate_zmagError on zmagmagstat.error;phot.magfloatJ/MNRAS/493/1761/tablea2Photometry of SN 2016gsd in the UBVRI bandsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhase relative to the explosion epoch (MJD=57648)dtime.phasefloatDateDate of observationtime.epochnullableMJDEpoch of the observationdtime.epochfloatTelTelescope used for the observationinstr.setupcharUmag? U-band magnitude (G1)magphot.mag;em.opt.Ufloatnullablee_Umag? Error on Umagmagstat.error;phot.magfloatnullableBmag? B-band magnitude (G1)magphot.mag;em.opt.Bfloatnullablee_Bmag? Error on Bmagmagstat.error;phot.magfloatnullableVmagV-band magnitude (G1)magphot.mag;em.opt.Vfloate_VmagError on Vmagmagstat.error;phot.magfloatRmag? R-band magnitude (G1)magphot.mag;em.opt.Rfloatnullablee_Rmag? Error on Rmagmagstat.error;phot.magfloatnullableImag? I-band magnitude (G1)magphot.mag;em.opt.Ifloatnullablee_Imag? Error on Imagmagstat.error;phot.magfloatnullableJ/MNRAS/493/1761/tablea3Photometry of SN 2016gsd in the ugriz bandsMJDEpoch of the observationdtime.epochfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhase relative to the explosion epoch (MJD=57648)dtime.phasefloatDateDate of observationtime.epochnullableTelTelescope used for the observationinstr.setupcharumag? u-band magnitude (G2)magphot.mag;em.opt.Ufloatnullablee_umag? Error on umagmagstat.error;phot.magfloatnullablegmag? g-band magnitude (G2)magphot.mag;em.opt.Bfloatnullablee_gmag? Error on gmagmagstat.error;phot.magfloatnullablermag? r-band magnitude (G2)magphot.mag;em.opt.Rfloatnullablee_rmag? Error on rmagmagstat.error;phot.magfloatnullableimag? i-band magnitude (G2)magphot.mag;em.opt.Ifloatnullablee_imag? Error on imagmagstat.error;phot.magfloatnullablezmag? z-band magnitude (G2)magphot.mag;em.opt.Ifloatnullablee_zmag? Error on zmagmagstat.error;phot.magfloatnullableJ/MNRAS/493/1761/tablea4Photometry of SN 2016gsd in the JHK bandsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhase relative to the explosion epoch (MJD=57648)dtime.phasefloatDateDate of observationtime.epochnullableMJDEpoch of the observationdtime.epochfloatInstInstrument used for the observationinstr.setupcharJmag? J-band magnitude in the Vega systemmagphot.mag;em.IR.Jfloatnullablee_Jmag? Error on Jmagmagstat.error;phot.magfloatnullableHmag? H-band magnitude in the Vega systemmagphot.mag;em.IR.Hfloatnullablee_Hmag? Error on Hmagmagstat.error;phot.magfloatnullablel_KmagLimit flag on Kmagmeta.code.errorcharKmag? K-band magnitude in the Vega systemmagphot.mag;em.IR.Kfloatnullablee_Kmag? Error on Kmagmagstat.error;phot.magfloatnullableJ/MNRAS/493/1761/tablea5Log of spectroscopic observationsGrismGrismmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhase relative to the explosion epoch (MJD=57648)dtime.phasefloatDateDate of observationtime.epochnullableMJDEpoch of the observationdtime.epochfloatTelTelescope used for the observationinstr.setupcharInstInstrument used for the observationinstr.setupcharRangeWavelength range0.1nminstr.bandwidthchar