J/A+A/698/A129ivo://CDS.VizieR/J/A+A/698/A129doi:10.26093/cds/vizier/bc-nt/lbcjCDSReguitti A.Pastorello A.Smartt S.J.Valerin G.Pignata G.Campana S.,Chen T.-W.Sankar A.K.Moran S.Mazzali P.A.Duarte J.Salmaso I.,Anderson J.P.Ashall C.Benetti S.Gromadzki M.Gutierrez C.P.,Humina C.Inserra C.Kankare E.Kravtsov T.Muller-Bravo T.E.,Pessi P.J.Sollerman J.Young D.R.Chambers K.de Boer T.Gao H.,Huber M.Lin C.-C.Lowe T.Magnier E.Minguez P.Smith I.A.,Smith K.W.Srivastav S.Wainscoat R.Benedet M.2026-07-03T06:37:10Z2025-06-06T09:12:18ZCDS support team

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

cds-question@unistra.frsupernovaeccd-photometryvisible-astronomyultraviolet-astronomyWe present photometric and spectroscopic data of the type IIb supernova (SN) 2024abfo in NGC 1493 (at 11Mpc). The ATLAS survey discovered the object just a few hours after the explosion, and observed a fast rise on the first day. Signs of the sharp shock break-out peak and the subsequent cooling phase are observed in the ultraviolet and the bluest optical bands in the first couple of days, while no peak is visible in the reddest filters. Subsequently, in analogy with normal SNe IIb, the light curve of SN 2024abfo rises again in all bands to the broad peak, with the maximum light reached around one month after the explosion. Its absolute magnitude at peak is Mr=-16.5+/-0.1mag, making it a faint SN IIb. The early spectra are dominated by Balmer lines with broad P-Cygni profiles indicating ejecta velocity of 22500km/s. One month after the explosion, the spectra display a transition towards being He-dominated, though the H lines do not completely disappear, supporting the classification of SN 2024abfo as a relatively H-rich SN IIb. We identify the progenitor of SN 2024abfo in archival images of the Hubble Space Telescope, the Dark Energy Survey, and the XMM-Newton space telescope, in multiple optical filters. From its spectral energy distribution, the progenitor is consistent with being a yellow supergiant, having an initial mass of 15M_{sun}. This detection supports an emerging trend of SN IIb progenitors being more luminous and hotter than SN II ones, and being primaries of massive binaries. Within the SN IIb class, fainter events such as SN 2024abfo tend to have cooler and more expanded progenitors than luminous SNe IIb.2025A&A...698A.129Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/698/A129CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/698/A129https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/698/A129http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/698/A129https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/698/A129https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/698/A129http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/698/A129GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticaldefaultJ/A+A/698/A129/atlasMagnitudes of SN 2024abfo in the ATLAS orange and cyan filtersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date'Y:M:D'time.epoch;obsnullableMJDModified Julian datedtime.epochdoubleFilterFilter (1)meta.id;instr.filtercharmagMagnitude in Filtermagphot.magfloate_mag? Magnitude errormagstat.error;phot.magfloatnullableFlag[PU] P = Detection, U = Upper limitmeta.code.errorcharInstCombination of Telescope, InstrumentinstrcharJ/A+A/698/A129/johnsonMagnitudes of SN 2024abfo in the Johnson UBV filtersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date'Y:M:D'time.epoch;obsnullableMJDModified Julian datedtime.epochdoubleFilterFilter (1)meta.id;instr.filtercharmagMagnitude in Filtermagphot.magfloate_mag? Magnitude errormagstat.error;phot.magfloatnullableFlag[PU] P = Detection, U = Upper limitmeta.code.errorcharInstCombination of Telescope, InstrumentinstrcharJ/A+A/698/A129/sloanMagnitudes of SN 2024abfo in the Sloan griz filtersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date'Y:M:D'time.epoch;obsnullableMJDModified Julian datedtime.epochdoubleFilterFilter (1)meta.id;instr.filtercharmagMagnitude in Filtermagphot.magfloate_mag? Magnitude errormagstat.error;phot.magfloatnullableFlag[PU] P = Detection, U = Upper limitmeta.code.errorcharInstCombination of Telescope, InstrumentinstrcharJ/A+A/698/A129/swiftMagnitudes of SN 2024abfo from Swift/UVOTrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date'Y:M:D'time.epoch;obsnullableMJDModified Julian datedtime.epochdoubleFilterFilter (1)meta.id;instr.filtercharmagMagnitude in Filtermagphot.magfloate_mag? Magnitude errormagstat.error;phot.magfloatnullableFlag[PU] P = Detection, U = Upper limitmeta.code.errorcharInstCombination of Telescope, Instrumentinstrchar