J/ApJ/945/L7ivo://CDS.VizieR/J/ApJ/945/L7CDSKospal A.Abraham P.Diehl L.Banzatti A.Bouwman J.Chen L.,Cruz-Saenz de Miera F.Green J.D.Henning T.Rab C.2025-03-21T14:59:47Z2025-03-21T15:46:45ZCDS support team

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

cds-question@unistra.frinfrared-astronomyspectroscopyvariable-starspre-main-sequence-starsEX Lup is a low-mass pre-main-sequence star that occasionally shows accretion-related outbursts. Here, we present JWST/MIRI medium-resolution spectroscopy obtained for EX Lup 14 yr after its powerful outburst. EX Lup is now in quiescence and displays a Class II spectrum. We detect a forest of emission lines from molecules previously identified in infrared spectra of classical T Tauri disks: H2O, OH, H2, HCN, C2H2, and CO2. The detection of organic molecules demonstrates that they are back after disappearing during the large outburst. Spectral lines from water and OH are for the first time deblended and will provide a much-improved characterization of their distribution and density in the inner disk. The spectrum also shows broad emission bands from warm, submicron-size amorphous silicate grains at 10 and 18{mu}m. During the outburst, in 2008, crystalline forsterite grains were annealed in the inner disk within 1au, but their spectral signatures in the 10{mu}m silicate band later disappeared. With JWST we rediscovered these crystals via their 19.0, 20.0, and 23.5{mu}m emission, the strength of which implies that the particles are at ~3au from the star. This suggests that crystalline grains formed in 2008 were transported outwards and now approach the water snowline, where they may be incorporated into planetesimals. Containing several key tracers of planetesimal and planet formation, EX Lup is an ideal laboratory to study the effects of variable luminosity on the planet-forming material and may provide an explanation for the observed high crystalline fraction in solar system comets.2023ApJ...945L...7Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/945/L7CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/147/305 : IUE atlas of pre-main-sequence stars (Valenti+, 2003)J/ApJ/678/985 : c2d Spitzer survey of interstellar ices. I. (Boogert+, 2008)J/A+A/507/881 : Emission lines in EX Lup optical spectrum (Sipos+, 2009)J/ApJS/201/11 : MIR spectral variability atlas of YSOs (Kospal+, 2012)J/PASP/125/477 : Gas Survey of Protoplanetary Systems. I. (Dent+, 2013)J/A+A/630/A58 : Full infrared spectrum of molecular hydrogen (Roueff+, 2019)J/A+A/636/A74 : HARPS radial velocity database (Trifonov+, 2020)J/A+A/641/A33 : EX Lup SPHERE and SINFONI images (Rigliaco+, 2020)J/AJ/163/174 : IRTF/VLT M-band spectroscopic survey (Banzatti+, 2022)J/AJ/165/72 : IR water vapor em. from planet-forming disks (Banzatti+, 2023)J/MNRAS/526/4885 : Stable accretion of EX Lup & TW Hya (Sicilia-Aguilar+, 2023)J/A+A/684/A73 : Polarimetric Diff. Imaging with VLT/NACO (de Regt+, 2024)J/A+A/691/A18 : EX Lup ESPaDOnS and SPIRou spectra (Pouilly+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/945/L7https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/945/L7http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/945/L7https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/945/L7https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/945/L7http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/945/L7GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/945/L7/fig1JWST/MIRI MRS spectrum of EX LuprecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4.9/28] Wavelengthumem.wlfloatFlux[0.18/1.16] FluxJyphot.flux.density;em.IRdoubleChannelMIRI MRS channel (ch1 to ch4) and sub-band (short, medium, or long) (1)meta.id;instr.filterchar