J/ApJ/936/64ivo://CDS.VizieR/J/ApJ/936/64doi:10.26093/cds/vizier.19360064CDSSzabo Z.M.Kospal A.Abraham P.Park S.Siwak M.Green J.D.Pal A.,Acosta-Pulido J.A.Lee J.-E.Ibrahimov M.Grankin K.Kovacs B.,Bora Z.Bodi A.Cseh B.Csornyei G.Drozdz M.Hanyecz O.Ignacz B.,Kalup C.Konyves-Toth R.Krezinger M.Kriskovics L.Ogloza W.,Ordasi A.Sarneczky K.Seli B.Szakats R.Sodor A.Szing A.Vida K.,Vinko J.2024-11-06T20:27:23Z2024-07-04T10:11:36ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinfrared-photometryvisible-astronomybroad-band-photometryHistorically, FU Orionis-type stars are low-mass, pre-main-sequence stars. The members of this class experience powerful accretion outbursts and remain in an enhanced accretion state for decades or centuries. V1515Cyg, a classical FUor, started brightening in the 1940s and reached its peak brightness in the late 1970s. Following a sudden decrease in brightness, it stayed in a minimum state for a few months, then started brightening for several years. We present the results of our ground-based photometric monitoring complemented with optical/near-infrared spectroscopic monitoring. Our light curves show a long- term fading with strong variability on weekly and monthly timescales. The optical spectra show PCygni profiles and broad blueshifted absorption lines, common properties of FUors. However, V1515Cyg lacks the PCygni profile in the CaII 8498{AA} line, a part of the Ca infrared triplet, formed by an outflowing wind, suggesting that the absorbing gas in the wind is optically thin. The newly obtained near-infrared spectrum shows the strengthening of the CO bandhead and the FeH molecular band, indicating that the disk has become cooler since the last spectroscopic observation in 2015. The current luminosity of the accretion disk dropped from the peak value of 138L{sun} to about 45L{\sun}, suggesting that the long-term fading is also partly caused by the dropping of the accretion rate.2022ApJ...936...64Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/936/64CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/101/59 : 1-20um observations of Herbig-Haro objects (Molinari+ 1993)J/AJ/118/1043 : Herbig Ae/Be stars catalog (Herbst+, 1999)J/AJ/147/140 : SED of 24 class I & class II FU Orionis stars (Gramajo+, 2014)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)J/A+A/600/A20 : Lupus YSOs X-shooter spectroscopy (Alcala+, 2017)J/A+A/607/A39 : 7 FU Orionis-type stars CO spectral cubes (Feher+, 2017)J/A+A/618/A79 : FU Orionis small-amplitude light variations (Siwak+, 2018)J/ApJ/874/82 : Follow-up photometry & spectro of PTF14jg (Hillenbrand+, 2019)J/A+A/625/A49 : Dimming event of RW Aurigae A (Koutoulaki+, 2019)J/ApJ/878/134 : HARPS & X-shooter spectra Southern M dwarfs (Kuznetsov+ 2019)J/A+A/644/A135 : V646Pup TESS and ground photometry and spectrum (Siwak+, 2020)J/ApJ/917/80 : Opt-to-IR monitoring obs. of V1057 Cyg (Szabo+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/936/64https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/936/64http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/936/64https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/936/64https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/936/64http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/936/64GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/936/64/table4New Optical and near-IR photometry of V1515 CygrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstrInstrumentmeta.id;instrcharFiltFiltermeta.id;instr.filtercharJD[2453652/2459727] Julian Date of Observationdtime.epochdoubleomag[7.51/16.4] Observed magnitude in Filtermagphot.mag;em.optdoublee_omag[7e-05/0.07] Uncertainty in omag (1)magstat.error;phot.magdoubleerr2[0.0001/0.2]? other uncertainty quotedmagstat.error;phot.magdoublenullableJ/ApJ/936/64/fig1Photometric light curve of V1515 CygrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstrInstrument/Source (1)meta.notecharFiltFiltermeta.id;instr.filtercharJD[2416387/2459330] Julian Date of Observationdtime.epochdoubleomag[1.26,17.8] Observed magnitude in Filtermagphot.mag;em.optdoublee_omag[0.01/4.04] Uncertainty in omagmagstat.error;phot.magdouble