J/ApJ/952/86ivo://CDS.VizieR/J/ApJ/952/86doi:10.26093/cds/vizier/ba-xr-2pCDSShivkumar H.Jaodand A.D.Balasubramanian A.Fremling C.Corsi A.,Tzanidakis A.Nissanke S.Kasliwal M.Brightman M.Raaijmakers G.,Madsen K.K.Harrison F.Carbone D.N. A JDesert J.-M.Andreoni I.2026-07-02T12:00:13Z2025-10-08T14:35:23ZCDS support team

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

cds-question@unistra.frtransient-sourcesvisible-astronomyspectroscopyinfrared-photometrybroad-band-photometrysupernovaeWe present optical, radio, and X-ray observations of a rapidly evolving transient SN2019wxt (PS19hgw), discovered during the search for an electromagnetic counterpart to the gravitational-wave (GW) trigger S191213g. Although S191213g was not confirmed as a significant GW event in the off-line analysis of LIGO-Virgo data, SN2019wxt remained an interesting transient due to its peculiar nature. The optical/near-infrared (NIR) light curve of SN2019wxt displayed a double-peaked structure evolving rapidly in a manner analogous to currently known ultrastripped supernovae (USSNe) candidates. This double-peaked structure suggests the presence of an extended envelope around the progenitor, best modeled with two components: (i) early-time shock-cooling emission and (ii) late-time radioactive ^56^Ni decay. We constrain the ejecta mass of SN2019wxt at M_ej_~0.20M_{sun}_, which indicates a significantly stripped progenitor that was possibly in a binary system. We also followed up SN2019wxt with long-term Chandra and Jansky Very Large Array observations spanning ~260days. We detected no definitive counterparts at the location of SN2019wxt in these long-term X-ray and radio observational campaigns. We establish the X-ray upper limit at 9.93x10^-17^erg/cm^2^/s and detect an excess radio emission from the region of SN2019wxt. However, there is little evidence for SN1993J- or GW170817-like variability of the radio flux over the course of our observations. A substantial host-galaxy contribution to the measured radio flux is likely. The discovery and early-time peak capture of SN2019wxt in optical/NIR observations during EMGW follow-up observations highlight the need for dedicated early, multiband photometric observations to identify USSNe.2023ApJ...952...86Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/952/86CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/MNRAS/383/1485 : BVRI light curves of SN 2003jd (Valenti+, 2008)J/MNRAS/436/774 : Core collapse supernovae (type Ibc) (Eldridge+, 2013)J/MNRAS/431/308 : SN 2011fu BVRI light curves (Kumar+, 2013)J/A+A/561/A146 : SN 2010ae optical spectra (Stritzinger+, 2014)J/A+A/593/A68 : PTF12os and iPTF13bvn spectra and LCs (Fremling+, 2016)J/ApJ/848/L33 : Opt. follow-up of GW events with LCO (Arcavi+, 2017)J/other/Sci/362.201 : iPTF 14gqr (SN 2014ft) photometry (De+, 2018)J/ApJ/895/49 : Optical sp. of ZTF18abvkwla & its host galaxy (Ho+, 2020)J/ApJ/898/166 : UV to NIR obs. of SN 2019ehk (Jacobson-Galan+, 2020)J/ApJ/905/145 : ZTF cand. counterparts to GW follow-up (Kasliwal+, 2020)J/ApJ/900/46 : UV, optical and IR light curve of SN2019dge (Yao+, 2020)J/ApJ/918/63 : Fast-transients confirmed by ZTF & LCs (Andreoni+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/952/86https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/952/86http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/952/86https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/952/86https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/952/86http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/952/86GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/952/86/table7Summary of optical observations of SN2019wxtrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrumentmeta.id;instrcharAuthAuthor's name for the referencemeta.bib.authorcharBibCodeBibcode of the referencemeta.bib.bibcodecharMJD[58829.3/58854] Modified Julian Date of the observation (1)dtime.epochdoubleFiltFilter (g,r,i,z,y or J)meta.id;instr.filtercharl_magLimit flag on magmeta.code.errorcharmag[18.9/23.5] Magnitudemagphot.magfloate_mag[0.01/0.22]? Uncertainty on magmagstat.error;phot.magfloatnullableJ/ApJ/952/86/table8Summary of optical spectroscopic observations of SN2019wxtrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[58835.75/58836.22] Modified Julian Date of the start of observationdtime.epochdoubleTelTelescopemeta.id;instr.telcharInstInstrumentmeta.id;instrcharlambdaWavelength range in {AA}0.1nmem.wlcharExp[1200/3600] Exposure timestime.duration;obs.exposuredoubleResResolutionpos.angResolutioncharPhase[2.45/2.91] Phase; column added by CDS (from Data behind Figure 8)dtime.phasefloatFileName of the file in ASCII format in subdirectory "sp"; column added by CDSmeta.id;meta.filecharspInteractive spectrum Plotmeta.ref.urlchar