J/A+A/706/A271ivo://CDS.VizieR/J/A+A/706/A271CDSZhao J.-W.Benetti S.Cai Y.-Z.Pastorello A.Elias-Rosa N.,Reguitti A.Valerin G.Wang Z.-Y.Cappellaro E.Feng G.-F.Fiore A.,Fitzpatrick B.Fraser M.Isern J.Kankare E.Kravtsov T.Kumar B.,Lundqvist P.Matilainen K.Mattila S.Mazzali P.A.Moran S.Ochner P.,Peng Z.-H.Reynolds T.M.Salmaso I.Srivastav S.Stritzinger M.D.,Taubenberger S.Tomasella L.Vinko J.Wheeler J.C.Williams S.,Pei S.-P.Yang Y.-J.Liu X.-K.Liu X.-W.Yang Y.-P.2026-03-02T06:25:50Z2026-02-16T09:35:53ZCDS support team

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

cds-question@unistra.frsupernovaephotometryvisible-astronomyinfrared-astronomyType IIb supernovae (SNe IIb) are stellar explosions whose spectra show transitional features between hydrogen-rich (Type II) and helium-rich (Type Ib) SNe. Their progenitors are massive stars that were mostly stripped of their hydrogen envelope, most likely through binary interaction and/or strong stellar winds, making them key tools for studying the late stages of the evolution of massive stars. An extensive photometric and spectroscopic follow-up campaign of the Type IIb SN 2022ngb is presented in the article. Through detailed modeling of this dataset, we aim to constrain the key physical parameters of the explosion, infer the nature of the progenitor star and its environment, and probe the dynamical properties of the ejecta. We analyze photometric and spectroscopic data of SN 2022ngb. By constructing and modeling the bolometric light curve with semi-analytic models, we estimate the primary explosion parameters. The spectroscopic data are compared with those of well- studied SNe IIb and NLTE models to constrain the properties of the progenitor and the structure of the resulting ejecta. SN 2022ngb is a low-luminosity SN IIb with a peak bolometric luminosity of L_Bol_=7.76(+1.15/-1.00)x10^41^erg/s and a V-band rising time of 24.32+/-0.50 days. Light curve modeling indicates an ejecta mass of ~2.9-3.2M_{sun}_, an explosion energy of ~1.4x10^51^erg, and a low synthesized 56Ni mass of ~0.045M_{sun}_. Nebular phase spectra exhibit asymmetric line profiles, pointing to a non-spherical explosion and an anisotropic distribution of radioactive material. Our analysis reveals a relatively compact stripped-envelope progenitor with a pre- SN mass of approximately 4.7M_{sun}_ (corresponding to a 15-16M_{sun}_ ZAMS star). Our analysis suggests that SN 2022ngb originated from the explosion of a moderate-mass relatively compact, stripped-envelope star in a binary system. The asymmetries inferred from the nebular phase spectral line features suggest a non-spherical explosion.2026A&A...706A.271Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/706/A271CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/706/A271https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/706/A271http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/706/A271https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/706/A271https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/706/A271http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/706/A271GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+A/706/A271/22ngbMulti-band photometric data for SN 2022ngbrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation datetime.epoch;obsnullableMJDMJD of the observationdtime.epoch;obsdoublemagObserved apparent magnitudemagphot.magfloate_mag? Uncertainty of the magnitudemagstat.error;phot.magfloatnullableBandPhotometric filter/band name (1)meta.idcharSystemPhotometric system (e.g. Vega, AB)meta.codecharType[P/U] Type of observation (U for upper limit magnitude)meta.notecharInstName of the instrument for the observationmeta.id;instrcharTelName of the telescope for the observationmeta.id;instr.telchar