J/A+A/700/A138ivo://CDS.VizieR/J/A+A/700/A138doi:10.26093/cds/vizier/bc-nw/lbdiCDSCharalampopoulos P.Kotak R.Sollerman J.Gutierrez C.P.Pursiainen M.,Killestein T.L.Schulze S.Pessi P.J.Maeda K.Kangas T.Cai Y.-Z.,Fremling C.Hinds K.R.Jegou du Laz T.Kankare E.Kasliwal M.,Kuncarayakti H.Lundqvist P.Masci F.J.Mattila S.Perley D.A.,Reguitti A.Reynolds T.M.Stritzinger M.Tartaglia L.Van Roestel J.,Wold A.2026-08-03T06:56:11Z2025-08-13T07:39:53ZCDS support team

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

cds-question@unistra.frsupernovaevisible-astronomysloan-photometryWe present an analysis of the optical and near-infrared properties of SN 2022lxg, a bright (Mg_peak_=-19.41mag) and rapidly evolving SN. It was discovered within a day of explosion, and rose to peak brightness in ~10d. Two distinct phases of circumstellar interaction are evident in the data. The first is marked by a steep blue continuum (T>15000K) with flash-ionisation features due to hydrogen and HeII. The second, weaker phase is marked by a change in the colour evolution accompanied by changes in the shapes and velocities of the spectral line profiles. Narrow P-Cygni profiles (~150km/s) of HeI further indicate the presence of slow-moving unshocked material and suggesting partial stripping of the progenitor. The fast decline of the light curve from peak (3.48+/-0.26mag(50d)^-1^ in g-band) implies that the ejecta mass must be low. Spectroscopically, until +35d there are similarities to some Type IIb SNe but then there is a transition to spectra that are more reminiscent of an interacting SN II. However, metal lines are largely absent in the spectra, even at epochs of ~80d. Its remote location (~4.6kpc projected offset) from the presumed host galaxy, a dwarf with MB~-14.4mag, is consistent with our metallicity estimate -- close to the Small Magellanic Cloud value -- obtained from scaling relations. Furthermore, several lines of evidence (including intrinsic polarisation of p~(0.5-1.0)%) point to deviations from spherical symmetry. We suggest that a plausible way of uniting the observational clues is to consider a binary system that underwent case C mass transfer. This failed to remove the entire H-envelope of the progenitor before it underwent core-collapse. In this scenario, the progenitor itself would be more compact and perhaps straddle the boundary between blue and yellow supergiants, tying in with the early spectroscopic similarity to Type IIb SNe.2025A&A...700A.138Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/700/A138CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/700/A138https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/700/A138http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/700/A138https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/700/A138https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/700/A138http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/700/A138GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/700/A138/tablea1Photometry of SN 2022lxgrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date'Y:M:D'time.epoch;obsnullableMJDModified Julain datedtime.epochdoublePhasePhase wrt to explosion epochdtime.phasefloatTelTelescopemeta.id;instr.telcharBand[oc griz] Bandinstr.bandpasscharl_magUpper limit flag on magmeta.code.errorcharmagMagnitude in Bandmagphot.magfloate_mag? Magnitude in Band errormagstat.error;phot.magfloatnullable