J/A+A/706/A154ivo://CDS.VizieR/J/A+A/706/A154CDSReguitti A.Pastorello A.Valerin G.2026-03-02T06:25:50Z2026-02-06T08:24:19ZCDS support team

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

cds-question@unistra.frnovaephotometryinfrared-astronomyWe present late-time optical and infrared (IR) observations of a sample of nine extragalactic luminous red novae (LRNe) discovered in the past three decades. In all of these cases, the LRN survivors fade below the pre-outburst luminosity of the progenitors in the optical region. However, they remain visible in the near-IR (NIR) and bright in the mid-IR (MIR) domains for years. We recover AT 1997bs in Spitzer images from 2004, and a residual source is visible in HST and JWST NIR images 27 years after the outburst. The spectral energy distribution (SED) of AT 1997bs is consistent with that of an orange giant star with a photospheric temperature of 3750-4250K and a radius of 120-150R_{Sun}_, without a significant circumstellar dust attenuation. Similarly, the SED of AT 2019zhd after three years is compatible with a red supergiant star with Tph~3100+/-100K and R~350+/-50R_{Sun}_. Another LRN, AT 2011kp, is detected by JWST 12.5 years after the outburst. Its SED, with two excesses at 1.8 and 7.7{mu}m, can be explained by a cold (T~450K) dusty shell composed of amorphous carbon surrounding a cold expanded source, plus emission from the Pa{alpha} line. We constructed the [3.6]-[4.5] colour curves extending up to more than 7 years for six LRNe, which show a similar evolution: The MIR colour is ~-0.5mag before the optical maximum light, it becomes bluer after around one year, and then it gradually turns to redder colours in the following years before reaching [3.6]-[4.5]~+1.0mag 7 years after the outburst. We also estimated the masses and the temperatures of newly formed dust years after the LRN onset. We find that LRNe produce dust masses of the order of (1-5)*10^-4^ (and up to 2*10^-3^) M_{Sun}_ between 7 and 13 years after the outbursts. Finally, we find that the remnants of LRNe detected years or decades after the merger tend to be expanded and cool objects, similar to red supergiant stars.2026A&A...706A.154Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/706/A154CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/695/A42 : Data collected for 4 ILRTs (Valerin+, 2025)J/A+A/686/A45 : Binary mass transfer model data (Schneider+, 2024)J/A+A/671/A158 : Three luminous red novae light curves (Pastorello+, 2023)J/A+A/667/A4 : NGC4631 luminous red nova AT 2021biy light curves (Cai+, 2022)J/A+A/654/A157 : 5 ILRTs light curves and spectra (Cai+, 2021)J/A+A/653/A134 : AT 2018bwo light curves (Blagorodnova+, 2021)J/A+A/647/A93 : AT 2020hat and AT 2020kog light curves (Pastorello+, 2021)J/A+A/646/A119 : M31 luminous red nova AT 2019zhd photometry (Pastorello+,2021)J/A+A/632/L6 : AT 2018hso light curves and spectra (Cai+, 2019)J/A+A/630/A75 : Six luminous red novae photometry (Pastorello+, 2019)J/A+A/625/L8 : SN 2017jfs optical and NIR light curves (Pastorello+, 2019)J/A+A/418/869 : M31-RV evolution (1942-1993) (Boschi+, 2004)J/ApJ/894/111 : Gemini/GMOS-S spectra of the type IIn SN 2010jl (Bevan+, 2020)J/ApJ/834/107 : Follow-up photometry of M101 OT2015-1 (Blagorodnova+, 2017)J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/706/A154https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/706/A154http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/706/A154https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/706/A154https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/706/A154http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/706/A154GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/706/A154/lrne (Extragalactic luminous red nova sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/706/A154/lrne?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/706/A154/lrne?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/706/A154/lrne?GETtext/xml+votable180.050000true170.05937512.97211110.0055555555555555566/2708 7534 7997 10905 11434 16605 20002 24912 28167https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/706/A154?format=asciiInfrareddefaultJ/A+A/706/A154/lrneExtragalactic luminous red nova samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject names of the extragalactic luminous red novae LRNe (Object)meta.id;meta.maincharRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainNbrNumber of occurence in table.datmeta.numberintLCLight curvesmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/A+A/706/A154/tablePhotometry magnitudes for the nine extragalactic luminous red novaerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject names of the extragalactic luminous red novae LRNe (Object)meta.id;meta.maincharMJDModified julian date (MJD)dtime.epochdoubleFilterPhotometric filter (Filter)meta.id;instr.filtercharSystem[vega ab] Photometric system (System)photcharmagApparent magnitude (Mag)magphot.magfloate_magUncertainty of the magnitude (eMag)magstat.error;phot.magfloatDet[P U] Detection flag P=yes and U=no (Detection)meta.notecharInstInstrument used (Instrument) (1)instr.setupchar