J/A+A/706/A381ivo://CDS.VizieR/J/A+A/706/A381doi:10.26093/cds/vizier/bc-p2/ldibCDSIzzo L.Gall C.Khetan N.Earl N.Hjorth J.Hoogendam W.B.Ni Y.Q.,Sedgewick A.Ward S.M.Zenati Y.Auchettl K.Bhattacharjee S.,Benetti S.Branchesi M.Cappellaro E.Catapano A.Chambers K.C.,Coulter D.A.Davis K.W.Della Valle M.Dhawan S.de Boer T.,Dimitriadis G.Foley R.J.Fulton M.Gao H.Hon W.J.Huber M.E.,Jones D.O.Kilpatrick C.D.Lin C.C.Lowe T.B.Magnier E.A.Mandel K.S.,Margutti R.Narayan G.Ochner P.Pan Y.C.Reguitti A.Rojas-Bravo C.,Siebert M.Smartt S.J.Smith K.W.Srivastav S.Swift J.J.Taggart K.,Terreran G.Thorp S.Tomasella L.Wainscoat R.J.2026-02-25T08:51:23Z2026-02-23T09:29:42ZCDS support team

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

cds-question@unistra.frsupernovaeinfrared-photometryvisible-astronomybroad-band-photometrysloan-photometryultraviolet-astronomyType Ia supernovae (SNe Ia) are among the most precise cosmological distance indicators used to study the expansion history of the Universe. The vast increase of SN Ia data due to large-scale astrophysical surveys has led to the discovery of a wide variety of SN Ia sub-classes, such as transitional and fast-declining SNe Ia. However, their distinct photometric and spectroscopic properties differentiate them from the population of normal SNe Ia such that their use as cosmological tools remains challenged. Here, we present a high-cadenced photometric and spectroscopic dataset of two SNe Ia, SNe 2020ue and 2020nlb, which were discovered in the nearby Virgo cluster of galaxies. Our study shows that SN 2020nlb is a normal SN Ia whose unusually red color is intrinsic, arising from a lower photospheric temperature rather than interstellar reddening, providing clear evidence that color diversity among normal SNe Ia can have a physical origin. In contrast, SN 2020ue has photometric properties, such as color evolution and light-curve decay rate, similar to those of transitional SNe, spectroscopically it is more aligned with normal SNe Ia. This is evident from spectroscopic indicators such as the pseudo-equivalent width of Si ii lines. Thus, such SNe Ia that are photometrically at the edge of the standard normal SNe Ia range may be missed in cosmological SNe Ia samples. Our results highlight that spectroscopic analysis of SNe Ia around peak brightness is crucial for identifying intrinsic color variations and constructing a more complete and physically homogeneous SN Ia2026A&A...706A.381Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/706/A381CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/706/A381https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/706/A381http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/706/A381https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/706/A381https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/706/A381http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/706/A381GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/706/A381/sn (List of studied SN)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/706/A381/sn?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/706/A381/sn?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/706/A381/sn?GETtext/xml+votable180.050000true190.6948752.65947220.0055555555555555566/26313 28045https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/706/A381?format=asciiUVOpticalInfrareddefaultJ/A+A/706/A381/snList of studied SNrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSN name (SN 2020nlb or SN 2020ue)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainJ/A+A/706/A381/tablesTables of the photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSN name (SN 2020nlb or SN 2020ue)meta.id;meta.maincharBandObserved bandinstr.bandpasscharMJDModified Julian datedtime.epochdoublePhasePhasedtime.phasefloatmagMagnitude in Band (1)magphot.magfloate_magMagnitude in Band errormagstat.error;phot.magfloatTelTelescopemeta.id;instr.telchar