J/A+A/704/A89ivo://CDS.VizieR/J/A+A/704/A89CDSde Wet S.Leloudas G.Buckley D.Erasmus N.Groot P.J.Zimmerman E.2026-03-02T06:25:50Z2025-12-02T08:13:43ZCDS support team

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

cds-question@unistra.frsupernovaeultraviolet-photometryvisible-astronomyType IIb supernovae (SNe) are a transitional subclass of stripped-envelope SNe showing hydrogen lines in their spectra that gradually weaken and give way to helium lines reminiscent of SNe Ib. The presence of hydrogen indicates that they retain a non-negligible hydrogen-rich envelope that has been stripped through stellar winds or binary interaction. The direct detection of SN progenitors is a valuable way to connect the various supernova sub-types with their progenitor stars. SN 2024abfo is the seventh SN IIb with a direct progenitor detection. Our aim is to study the progenitor candidate and the supernova itself to determine the evolutionary history of the system. We astrometrically register our ERIS adaptive optics imaging with archival HST imaging to determine whether the supernova position is consistent with the progenitor candidate position. We perform photometry on archival DECam imaging to derive the spectral energy distribution of the progenitor candidate and investigate its temporal variability. We consider single and binary star models to explain the end point of the progenitor candidate in the Hertzsprung-Russell diagram. For the supernova we compare the light curves and spectra with other SNe IIb with progenitor detections. We derive the bolometric light curve and attempt to fit this with a semi-analytic light curve model. The position of the supernova in our adaptive optics imaging agrees with the progenitor position to within 20 mas. The progenitor SED is consistent with an A3V star with a radius of ~120 solar radii, a temperature of ~8800K, and a luminosity of log(L/L_{sun_})~4.9. Single star models predict an initial mass in the range 12-16 M_sun, while the most probable binary model is a 12+1.2M_{sun}_ system with an initial period of 1.73 years. We also find significant evidence for variability of the progenitor candidate in the years prior to core-collapse. SN 2024abfo is the least luminous SN IIb with a direct progenitor detection. At late times the r-band light curve decays more slowly than the comparison SNe, which may be due to increased gamma-ray trapping, although this requires further investigation. Similar to SN 2008ax, SN 2024abfo does not show a prominent double-peaked light curve. Our semi- analytic light curve modelling shows that this may be due to a very low mass of hydrogen <0.006 M_sun in the outer envelope. Spectrally, SN 2024abfo is most similar to SN 2008ax at early times while at later times (~80 days) it appears to show persistent Halpha absorption compared to the comparison sample. We prefer a binary system to explain SN 2024abfo and its progenitor, although we are unable to rule out single-star models. We recommend late-time observations to search for a binary companion and signatures of CSM-interaction. The absence of these features would support the hypothesis that SN 2024abfo resulted from a system which underwent a period of binary mass transfer well before (>1000~yr) the explosion, resulting in a low-mass (<0.01M_{sun}_) hydrogen-rich envelope.2025A&A...704A..89Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/704/A89CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/698/A129 : Photometric measurements of SN 2024abfo (Reguitti+, 2025)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/704/A89https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/704/A89http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/704/A89https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/704/A89https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/704/A89http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/704/A89GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticaldefaultJ/A+A/704/A89/photomUV/optical photometry of SN 2024abforecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhase[0.02/159.74] Days since explosiondtime.phasefloatTelTelescope/Instrumentmeta.notecharFiltPhotometric filter (1)instr.bandpasscharl_magUpper limit flag on magmeta.code.errorcharmagObserved magnitude in Filtermagphot.magfloate_mag? Magnitude error (2)magstat.error;phot.magfloatnullableJ/A+A/704/A89/bol_lcBolometric and pseudo-bolometric light curve for SN 2024abfo along with radius and temperature evolutionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhase[2.49/153.44] Days since explosiondtime.phasedoubleRBlackbody radiussolRadphys.size.radiusdoublee_RBlackbody radius errorsolRadstat.errordoubleTBlackbody temperatureKphys.temperaturedoublee_TBlackbody temperature errorKstat.errordoublelogLbolLogarithm of bolometric luminositylog(1e-07W)phys.luminositydoublee_logLbolLogarithm of bolometric luminosity errorlog(1e-07W)stat.errordoublelogpLbolLogarithm of pseudo-bolometric luminositylog(1e-07W)phys.luminositydoublee_logpLbolLogarithm of pseudo-bolometric luminosity errorlog(1e-07W)stat.errordouble