J/ApJ/954/155ivo://CDS.VizieR/J/ApJ/954/155doi:10.26093/cds/vizier/ba-xt-4vCDSTeja R.S.Singh A.Sahu D.K.Anupama G.C.Kumar B.Nakaoka T.,Kawabata K.S.Yamanaka M.Takey A.Kawabata M.2026-07-02T12:00:29Z2025-12-08T10:06:06ZCDS support team

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

cds-question@unistra.frsupernovaeinfrared-photometryvisible-astronomybroad-band-photometryultraviolet-astronomyspectroscopyWe present an extensive, panchromatic photometric (UV, optical, and near-IR) and low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj that occurred on the outskirts of the host galaxy NGC 6217. From the V-band light curve, we estimate the plateau length to be ~70+/-2days, placing it among the very few well-sampled short plateau supernovae (SNe). With V-band peak absolute magnitude M_V_<=-17.0+/-0.1mag, it falls in the middle of the luminosity distribution of the Type II SNe. The color evolution is typical to other Type II SNe except for an early elbow-like feature in the evolution of V-R color owing to its early transition from the plateau to the nebular phase. Using the expanding photospheric method, we present an independent estimate of the distance to SN 2018gj. We report the spectral evolution to be typical of a Type II SNe. However, we see a persistent blueshift in emission lines until the late nebular phase, not ordinarily observed in Type II SNe. The amount of radioactive nickel (^56^Ni) yield in the explosion was estimated to be 0.026+/-0.007M_{sun}_. We infer from semianalytical modeling, nebular spectrum, and 1D hydrodynamical modeling that the probable progenitor was a red supergiant with a zero-age-main-sequence mass <=13M_{sun}_. In the simulated hydrodynamical model light curves, reproducing the early optical bolometric light curve required an additional radiation source, which could be the interaction with the proximal circumstellar matter.2023ApJ...954..155Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/954/155CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/183 : UBVRI Photometric Standards (Landolt 1992)VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)J/MNRAS/372/1315 : UBVRI photometry of SN 2004et (Sahu+, 2006)J/AJ/131/2245 : BATC photometry of SN2004dj (Zhang+, 2006)J/AJ/137/4517 : UVOT light curves of supernovae (Brown+, 2009)J/MNRAS/394/2266 : SN 2005cs one-year photometry (Pastorello+, 2009)J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)J/MNRAS/408/827 : Simulations of supernova explosions (Dessart+, 2010)J/A+A/537/A141 : UBVRI light curves of SN 2009E (Pastorello+, 2012)J/ApJ/756/173 : Phot. of type IIn SNe 2005ip and 2006jd (Stritzinger+, 2012)J/MNRAS/433/1871 : UBVRI griz light curves of SN 2012aw (Bose+, 2013)J/MNRAS/436/774 : Core collapse supernovae (type Ibc) (Eldridge+, 2013)J/A+A/555/A142 : Spectra of 5 Type II supernovae (Inserra+, 2013)J/A+A/555/A10 : Light curves of 5 type IIn supernovae (Taddia+, 2013)J/MNRAS/442/844 : BVRI light curves of type II-P supernovae (Faran+, 2014)J/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)J/ApJ/799/208 : Type IIP supernovae from Pan-STARRS1 (Sanders+, 2015)J/MNRAS/450/3137 : Optical/NIR light curves of SN 2009ib (Takats+, 2015)J/AJ/151/33 : UBVRIz LCs of 51 Type II supernovae (Galbany+, 2016)J/ApJ/820/33 : R-band light curves of type II supernovae (Rubin+, 2016)J/MNRAS/459/3939 : Type II supernova light curves (Valenti+, 2016)J/ApJ/885/43 : UBVRI & ugriz phot. of supernova SN 2017gmr (Andrews+, 2019)J/MNRAS/488/4239 : SNe II & IIb optical light curves comparison (Pessi+, 2019)J/ApJ/895/31 : Photometric obs. of Type II SN 2018ivc (Bostroem+, 2020)J/A+A/655/A105 : 3 SN multiwavelength light curves (Sollerman+, 2021)J/A+A/655/A90 : SN 2020cxd multi-photometry (Yang+, 2021)J/ApJ/930/34 : HCT spectroscopic obs. of type IIP SN 2020jfo (Teja+, 2022)J/ApJ/952/119 : SNII in ZTF 1st phase survey sp. follow-up (Bruch+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/954/155https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/954/155http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/954/155https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/954/155https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/954/155http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/954/155GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap7.952274030004205e-20 1.2058628298368645e-18UVOpticalInfrareddefaultJ/ApJ/954/155/table3UBVRI photometric magnitudes of SN 2018gjrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation Date (UT)'Y:M:D'time.epoch;obsnullableJD[132.5/423.1] Julian Date, JD-2458000dtime.epochfloatPhase[4.7/295.3] Phase (with reference to the explosion date, JD2458127.8)dtime.phasefloatUmag[14/20.6]? HFOSC/HCT U-band (Johnson-Cousins-Glass) magnitude at Datemagphot.mag;em.opt.Ufloatnullablee_Umag[0.01/0.05]? Uncertainty in Umagmagstat.error;phot.mag;em.opt.UfloatnullableBmag[14.7/20.8]? HFOSC/HCT B-band (Johnson-Cousins-Glass) magnitude at Datemagphot.mag;em.opt.Bfloatnullablee_Bmag[0.01/0.04]? Uncertainty in Bmagmagstat.error;phot.mag;em.opt.BfloatnullableVmag[14.7/20.2] HFOSC/HCT V-band (Johnson-Cousins-Glass) magnitude at Datemagphot.mag;em.opt.Vfloate_Vmag[0.01/0.04] Uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatRmag[14.5/19.23] HFOSC/HCT R-band (Johnson-Cousins-Glass) magnitude at Datemagphot.mag;em.opt.Rfloate_Rmag[0.01/0.05] Uncertainty in Rmagmagstat.error;phot.mag;em.opt.RfloatImag[14.4/19.01] HFOSC/HCT I-band (Johnson-Cousins-Glass) magnitude at Datemagphot.mag;em.opt.Ifloate_Imag[0.01/0.04] Uncertainty in Imagmagstat.error;phot.mag;em.opt.IfloatJ/ApJ/954/155/table4Swift/UVOT photometry for SN 2018gjrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation Date (UT)'Y:M:D'time.epoch;obsnullableJD[134.6/142.7] Julian Date, JD-2458000dtime.epochfloatPhase[6.8/14.9] Phase (with reference to the explosion date, JD2458127.8)dtime.phasefloatUVW2[14/15.5]? Swift/UVOT UVW2-band magnitude at Datemagphot.mag;em.UV.100-200nmfloatnullablee_UVW2[0.03/0.04]? Uncertainty in UVW2magstat.error;phot.mag;em.UV.100-200nmfloatnullableUVM2[13.9/15.5]? Swift/UVOT UVM2-band magnitude at Datemagphot.mag;em.UV.200-300nmfloatnullablee_UVM2[0.03/0.06]? Uncertainty in UVM2magstat.error;phot.mag;em.UV.200-300nmfloatnullableUVW1[13.7/14.91]? Swift/UVOT UVW1-band magnitude at Datemagphot.mag;em.UV.200-300nmfloatnullablee_UVW1[0.03/0.04]? Uncertainty in UVW1magstat.error;phot.mag;em.UV.200-300nmfloatnullableUmag[13.7/14.34] Swift/UVOT U-band magnitude at Datemagphot.mag;em.opt.Ufloate_Umag[0.03/0.04] Uncertainty in Umagmagstat.error;phot.mag;em.opt.UfloatBmag[14.8/15.1] Swift/UVOT B-band magnitude at Datemagphot.mag;em.opt.Bfloate_Bmag[0.03/0.04] Uncertainty in Bmagmagstat.error;phot.mag;em.opt.BfloatVmag[14.7/15] Swift/UVOT V-band magnitude at Datemagphot.mag;em.opt.Vfloate_Vmag[0.04/0.06] Uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatJ/ApJ/954/155/table5JHKs photometric magnitudes of SN 2018gjrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation Date (UT)'Y:M:D'time.epoch;obsnullableJD[136.3/332] Julian Date, JD-2458000dtime.epochfloatPhase[8.5/204.2] Phase (with reference to the explosion date, JD2458127.8)dtime.phasefloatJmag[13.8/17]? HONIR/Kanata J-band (2MASS-calibrated) magnitude at Datemagphot.mag;em.IR.Jfloatnullablee_Jmag[0.02/0.3]? Uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[14/17.64]? HONIR/Kanata H-band (2MASS-calibrated) magnitude at Datemagphot.mag;em.IR.Hfloatnullablee_Hmag[0.02/0.3]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag[14/18]? HONIR/Kanata Ks-band (2MASS-calibrated) magnitude at Datemagphot.mag;em.IR.Kfloatnullablee_Ksmag[0.02/0.1]? Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatnullableJ/ApJ/954/155/table6Log of spectroscopic observations of SN 2018gjJD[132.5/423.1] Julian Date, JD-2458000dtime.epochfloatPhase[4.7/295.3] Phase (relative to the explosion epoch of JD 2458127.8)dtime.phasefloatlam1[3500/5200] Wavelength lower range in {AA}0.1nmem.wlintlam2[7800/9250] Wavelength upper range in {AA}0.1nmem.wlintGrismGrism(s) usedmeta.id;instrcharspInteractive spectrum plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of observation (UT)'Y:M:D'time.epochnullable