J/MNRAS/463/3813ivo://CDS.VizieR/J/MNRAS/463/3813doi:10.26093/cds/vizier.74633813CDSHoloien T.W.-S.Kochanek C.S.Prieto J.L.Grupe D.Chen P.,Godoy-Rivera D.Stanek K.Z.Shappee B.J.Dong S.Brown J.S.Basu U.,Beacom J.F.Bersier D.Brimacombe J.Carlson E.K.Falco E.,Johnston E.Madore B.F.Pojmanski G.Seibert M.2024-08-16T20:19:16Z2018-07-03T14:05:23ZCDS support team

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

cds-question@unistra.frsupernovaeinfrared-photometryvisible-astronomybroad-band-photometryWe present ground-based and Swift photometric and spectroscopic observations of the tidal disruption event (TDE) ASASSN-15oi, discovered at the centre of 2MASX J20390918-3045201 (d~=216Mpc) by the All-Sky Automated Survey for SuperNovae. The source peaked at a bolometric luminosity of L~=1.3x10^44^erg/s and radiated a total energy of E~=6.6x10^50^ erg over the first ~3.5 months of observations. The early optical/UV emission of the source can be fit by a blackbody with temperature increasing from T~=2x10^4^K to T~=4x10^4^K while the luminosity declines from L~=1.3x10^44^erg/s to L~=2.3x10^43^erg/s, requiring the photosphere to be shrinking rapidly. The optical/UV luminosity decline during this period is most consistent with an exponential decline, L{prop.to}e^-(t-t_0)/tau_^, with {tau}~=46.5d for t_0_~=57241.6 (MJD), while a power-law decline of L{prop.to}(t-t_0_)^-{alpha}^ with t_0_~=57212.3 and {alpha}=1.62 provides a moderately worse fit. ASASSN-15oi also exhibits roughly constant soft X-ray emission that is significantly weaker than the optical/UV emission. Spectra of the source show broad helium emission lines and strong blue continuum emission in early epochs, although these features fade rapidly and are not present ~3 months after discovery. The early spectroscopic features and colour evolution of ASASSN-15oi are consistent with a TDE, but the rapid spectral evolution is unique among optically selected TDEs.2016MNRAS.463.3813Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/463/3813CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/463/3813https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/463/3813http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/463/3813https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/463/3813https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/463/3813http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/463/3813GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/MNRAS/463/3813/tablea1Photometric data of ASASSN-15oirecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDObservation date (MJD)dtime.epochdoublemagMagnitude in Filter (Vega) (1)magphot.magfloate_magrms uncertainty on mag (Vega) (1)magstat.error;phot.magfloatFilt[UBVI M2 W1 W2] Filtermeta.id;instr.filtercharTel[LCOGT Swift] Telescopemeta.id;instr.telchar