J/ApJ/943/L15ivo://CDS.VizieR/J/ApJ/943/L15doi:10.26093/cds/vizier.19439015CDSWang Q.Armstrong P.Zenati Y.Ridden-Harper R.Rest A.Arcavi I.,Kilpatrick C.D.Foley R.J.Tucker B.E.Lidman C.Killestein T.L.,Shahbandeh M.Anderson J.P.Angulo R.Ashall C.Burke J.Chen T.-W.,von Coelln S.Dalrymple K.A.Davis K.W.Fulton M.D.Galbany L.,Gonzalez E.P.Gao B.Gromadzki M.Howell D.A.Ihanec N.Jencson J.E.,Jones D.O.Lyman J.D.McCully C.Muller-Bravo T.E.Newsome M.,Nicholl M.O'Neill D.Pellegrino C.Rest S.Smartt S.J.Smith K.,Srivastav S.Terreran G.Tinyanont S.Young D.R.Zenteno A.2025-02-27T20:13:15Z2025-01-27T15:34:05ZCDS support team

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

cds-question@unistra.frsupernovaephotometryvisible-astronomyspectroscopyinfrared-astronomyWe present early observations and analysis of the double-peaked Type IIb supernova (SN IIb) SN 2021zby. TESS captured the prominent early shock-cooling peak of SN 2021zby within the first ~10 days after explosion with a 30 minute cadence. We present optical and near-infrared spectral series of SN 2021zby, including three spectra during the shock-cooling phase. Using a multiband model fit, we find that the inferred properties of its progenitor are consistent with a red supergiant or yellow supergiant, with an envelope mass of ~0.30-0.65M_{sun}_ and an envelope radius of ~120-300R_{sun}_. These inferred progenitor properties are similar to those of other SNe IIb with a double-peaked feature, such as SNe 1993J, 2011dh, 2016gkg, and 2017jgh. This study further validates the importance of the high cadence and early coverage in resolving the shape of the shock-cooling light curve, while the multiband observations, particularly UV, are also necessary to fully constrain the progenitor properties.2023ApJ...943L..15Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/943/L15CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)VIII/77 : HI spectral properties of galaxies (Springob+, 2005)J/ApJ/742/L18 : Follow-up photometry of the SN IIb PTF 11eon (Arcavi+, 2011)J/ApJ/741/97 : Light curves of Ibc supernovae (Drout+, 2011)J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)J/ApJ/795/44 : PS1 SNe Ia (0.02<z<0.7) griz light curves (Rest+, 2014)J/MNRAS/438/L101 : First month on SN 2013ej (Valenti+, 2014)J/A+A/580/A142 : SN 2011dh. The first two years (Ergon+, 2015)J/A+A/579/A40 : PESSTO catalog (Smartt+, 2015)J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)J/ApJ/870/L1 : K2 obs. of type Ia supernova SN 2018oh (Dimitriadis+, 2019)J/A+A/656/A61 : SN Ib nebular phase properties (Dessart+, 2021)J/ApJ/908/51 : TESS early LCs of type Ia Supernovae (Fausnaugh+, 2021)J/ApJ/913/143 : Opt. light curves of the type Ic SN 2019stc (Gomez+, 2021)J/ApJ/923/167 : SN 2018agk spectra and NIR-UV light curves (Wang+, 2021)J/ApJ/938/19 : Opt. phot. and sp. monitoring of SN 2019esa (Andrews+, 2022)J/ApJ/924/15 : Final moments. I. Type II SN 2020tlf (Jacobson-Galan+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/943/L15https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/943/L15http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/943/L15https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/943/L15https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/943/L15http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/943/L15GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/943/L15/atlas (ATLAS light curve of SN 2021zby (data behind Figure 1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/943/L15/atlas?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/943/L15/atlas?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/943/L15/atlas?GETtext/xml+votable180.050000true45.1484411.84160.0055555555555555566/195https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/943/L15?format=asciiOpticalInfrareddefaultJ/ApJ/943/L15/table2Log of spectroscopic observations of SN 2021zbyspInteractive spectrum plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59476.7/59543.3] Modified Julian Datedtime.epochdoublePhase-t0[2.29/67.1] Phase relative to t_0_dtime.phasefloatPhase-tpk[-21.7/43.1] Phase relative to t_peak_dtime.phasefloatTelTelescope / InstrumentinstrcharRange1[3256/6848] Wavelength lower rangeem.wl;stat.minintRange2[7994/25378] Wavelength upper rangeem.wl;stat.maxintFileNameName of the MRT file in subdirectory "fig2"; column added by CDSmeta.id;meta.filecharJ/ApJ/943/L15/atlasATLAS light curve of SN 2021zby (data behind Figure 1)apfit[-0.55/-0.32] apfitstat.fit.paramfloatFlux[-217/11718] Flux in FiltuJyphot.flux.density;em.optinte_Flux[8/14100] Uncertainty in FluxuJystat.error;phot.fluxintFilt[co] Filtermeta.id;instr.filtercharerr[0] err (always "0")stat.errorintchi/N[0.49/3.2] chi/Nstat.fit.chi2floatRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainxpixelxpixelpixpos.cartesian.x;instr.detdoubleypixelypixelpixpos.cartesian.y;instr.detdoublemaj[1.74/3.85] majstat.error;phys.angSize.smajAxisfloatmin[1.65/3.32] minstat.error;phys.angSize.sminAxisfloatphi[-87/88] phistat.error;phys.angSizefloatmag5sig[14.2/19.8] mag5sigmagphot.mag;stat.maxfloatSky[14.77/21.56] Skymeta.notefloatObsObservation identifiermeta.id;obs.param;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59461.5/59532.4] Modified Julian date of observation (JD-2400000.5)dtime.epochdoublemag[-25.1/23.4] Observed magnitude in Filtmagphot.magfloate_mag[0.03/30] Uncertainty in magmagstat.error;phot.magfloatJ/ApJ/943/L15/decamCTIO/DECam light curve of SN 2021zby (data behind Figure 1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59498.2/59603.1] Modified Julian date of observation (JD-2400000.5)dtime.epochdoublemag[17/22]? Observed magnitude in Filtmagphot.magdoublenullablee_mag[0.06/4]? Uncertainty in magmagstat.error;phot.magdoublenullableFilt[ri] Filtermeta.id;instr.filtercharFlux[6e-06/0.0006]? Flux in FiltuJyphot.flux.densitydoublenullablee_Flux[3.8e-06/4.6e-05]? Uncertainty in FluxuJystat.error;phot.fluxdoublenullableJ/ApJ/943/L15/tessUnbinned TESS light curve of SN 2021zby (data behind Figure 1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59473.6/59498.4] Modified Julian date of observation (JD-2400000.5)dtime.epochdoubleFlux[-513/1451]? Fluxphot.flux.density;em.optdoublenullablee_Flux[0.2/154]? Uncertainty in Fluxstat.error;phot.fluxdoublenullableTmag[15.99/29.54]? TESS magnitudemagphot.mag;em.optdoublenullablee_Tmag[0.0008/9255]? Uncertainty in magmagstat.error;phot.magdoublenullableJ/ApJ/943/L15/tess-binBinned TESS light curve of SN 2021zby (data behind Figure 1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59473.7/59498.2] Modified Julian date of observation (JD-2400000.5)dtime.epochdoubleFlux[-9/608]? Fluxphot.flux.density;em.optdoublenullablee_Flux[55/378]? Uncertainty in Fluxstat.error;phot.fluxdoublenullableTmag[16.94/20.57]? TESS magnitudemagphot.mag;em.optdoublenullablee_Tmag[0.14/13]? Uncertainty in magmagstat.error;phot.magdoublenullable