J/ApJ/958/178ivo://CDS.VizieR/J/ApJ/958/178doi:10.26093/cds/vizier/ba-xy-5jCDSLiu C.Miller A.A.Boos S.J.Shen K.J.Townsley D.M.Schulze S.,Harvey L.Maguire K.Johansson J.Brink T.G.Burgaz U.,Dimitriadis G.Filippenko A.V.Hall S.Hinds K.-R.Hoffman A.,Karambelkar V.Kilpatrick C.D.Perley D.Pichay N.Sears H.,Sollerman J.Stein R.Terwel J.H.Zheng W.Graham M.J.Kasliwal M.M.,Lacroix L.Purdum J.Rusholme B.Wold A.2026-07-02T12:00:59Z2026-02-23T10:29:01ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomybroad-band-photometryultraviolet-astronomyWe present observations of SN 2022joj, a peculiar Type Ia supernova discovered by the Zwicky Transient Facility. SN 2022joj exhibits an unusually red gZTF-rZTF color at early times and a rapid blueward evolution afterward. Around maximum brightness, SN 2022joj shows a high luminosity (M_gZTF,max_~-19.7mag), a blue broadband color (gZTF-rZTF~-0.2mag), and shallow SiII absorption lines, consistent with those of overluminous, SN 1991T-like events. The maximum-light spectrum also shows prominent absorption around 4200{AA}, which resembles the TiII features in subluminous, SN 1991bg-like events. Despite the blue optical-band colors, SN 2022joj exhibits extremely red ultraviolet minus optical colors at maximum luminosity (u-v~0.6mag and uvw1-v~2.5mag), suggesting a suppression of flux at ~2500-4000{AA}. Strong CII lines are also detected at peak. We show that these unusual spectroscopic properties are broadly consistent with the helium-shell double detonation of a sub-Chandrasekhar mass (M~1M_{sun}_) carbon/oxygen white dwarf from a relatively massive helium shell (Ms~0.04-0.1M_{sun}_), if observed along a line of sight roughly opposite to where the shell initially detonates. None of the existing models could quantitatively explain all the peculiarities observed in SN 2022joj. The low flux ratio of [NiII]{lambda}7378 to [FeII]{lambda}7155 emission in the late-time nebular spectra indicates a low yield of stable Ni isotopes, favoring a sub-Chandrasekhar mass progenitor. The significant blueshift measured in the [FeII]{lambda}7155 line is also consistent with an asymmetric chemical distribution in the ejecta, as is predicted in double-detonation models.2023ApJ...958..178Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/958/178CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/135/1598 : Optical spectroscopy of type Ia supernovae (Matheson+, 2008)J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)J/ApJ/787/29 : UVOT phot. of Super-Chandrasekhar mass SNe Ia (Brown+, 2014)J/MNRAS/444/3258 : Velocities and EW of PTF SNe Ia (Maguire+, 2014)J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)J/ApJ/886/152 : ZTF early observations of Type Ia SNe. I. LCs (Yao+, 2019)J/ApJ/902/48 : ZTF early obs. of type Ia supernovae. III. (Bulla+, 2020)J/ApJ/905/58 : Local ZTF universe. I. Ca-rich gap transients (De+, 2020)J/ApJ/891/85 : Manganese abund. in GC & dSph galaxies (de los Reyes+, 2020)J/MNRAS/491/2902 : Sub-Chandrasekhar progenitors for Type Ia SNe (Flors+, 2020)J/ApJ/896/165 : Optical light curves of SN 2016hnk (Jacobson-Galan+, 2020)J/ApJ/902/47 : ZTF early obs. of type Ia SNe. II. Rise time (Miller+, 2020)J/ApJS/255/29 : PTF core-collapse SN host-galaxy sample. I. (Schulze+, 2021)J/ApJ/934/102 : Follow-up LCO phot. & spectra of SN 2016dsg (Dong+, 2022)J/ApJ/946/7 : BVI light curves and sp. of Type Ia SN 2018aoz (Ni+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/958/178https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/958/178http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/958/178https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/958/178https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/958/178http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/958/178GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticalInfrareddefaultJ/ApJ/958/178/table2Optical and UV photometry of SN2022jojrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[59707.2/59804.2] Observation date (JD-2400000.5)dtime.epochdoubleFilterFilter (1)meta.id;instr.filtercharomag[15.8/21] Observed magnitude in Filter (2)magphot.magfloate_omag[0.005/0.9] Uncertainty in omagmagstat.error;phot.magfloatn_omagMagnitude System, AB or Vegameta.note;phot.magcharTelTelescope used (3)meta.id;instr.telchar