J/ApJ/870/L1ivo://CDS.VizieR/J/ApJ/870/L1doi:10.26093/cds/vizier.18709001CDSDimitriadis G.Foley R.J.Rest A.Kasen D.Piro A.L.Polin A.,Jones D.O.Villar A.Narayan G.Coulter D. AKilpatrick C.D.,Pan Y.-C.Rojas-Bravo C.Fox O.D.Jha S.W.Nugent P.E.Riess A.G.,Scolnic D.Drout M.R.Barentsen G.Dotson J.Gully-Santiago M.,Hedges C.Cody A.M.Barclay T.Howell S.Garnavich P.,Tucker B.E.Shaya E.Mushotzky R.Olling R.P.Margheim S.Zenteno A.,Coughlin J.Van Cleve J.E.Vinicius de Miranda Cardoso J.Larson K.A.,McCalmont-Everton K.M.Peterson C.A.Ross S.E.Reedy L.H.,Osborne D.McGinn C.Kohnert L.Migliorini L.Wheaton A.Spencer B.,Labonde C.Castillo G.Beerman G.Steward K.Hanley M.Larsen R.,Gangopadhyay R.Kloetzel R.Weschler T.Nystrom V.Moffatt J.,Redick M.Griest K.Packard M.Muszynski M.Kampmeier J.Bjella R.,Flynn S.Elsaesser B.Chambers K.C.Flewelling H.A.Huber M.E.,Magnier E.A.Waters C.Z.Schultz A.S.B.Bulger J.Lowe T.B.,Willman M.Smartt S.J.Smith K.W.Points S.Strampelli G.M.,Brimacombe J.Chen P.Munoz J.A.Mutel R.L.Shields J.Vallely P.J.,Villanueva S.Li W.Wang X.Zhang J.Lin H.Mo J.Zhao X.,Sai H.Zhang X.Zhang K.Zhang T.Wang L.Zhang J.Baron E.,DerKacy J.M.Li L.Chen Z.Xiang D.Rui L.Wang L.Huang F.,Li X.Hosseinzadeh G.Howell D.A.Arcavi I.Hiramatsu D.Burke J.,Valenti S.Tonry J.L.Denneau L.Heinze A.N.Weiland H.Stalder B.,Vinko J.Sarneczky K.Pal A.Bodi A.Bognar Z.Csak B.Cseh B.,Csornyei G.Hanyecz O.Ignacz B.Kalup C.Konyves-Toth R.,Kriskovics L.Ordasi A.Rajmon I.Sodor A.Szabo R.Szakats R.,Zsidi G.Williams S.C.Nordin J.Cartier R.Frohmaier C.Galbany L.,Gutierrez C.P.Hook I.Inserra C.Smith M.Sand D.J.Andrews J.E.,Smith N.Bilinski C.2020-09-01T10:38:18Z2020-02-25T08:01:26ZCDS support team

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

cds-question@unistra.frsupernovaevisible-astronomyphotometryWe present an exquisite 30minute cadence Kepler (K2) light curve of the Type Ia supernova (SNIa) 2018oh All-Sky Automated Survey for Supernovae (ASASSN-18bt), starting weeks before explosion, covering the moment of explosion and the subsequent rise, and continuing past peak brightness. These data are supplemented by multi-color Panoramic Survey Telescope (Pan-STARRS1) and Rapid Response System 1 and Cerro Tololo Inter-American Observatory 4m Dark Energy Camera (CTIO 4-m DECam) observations obtained within hours of explosion. The K2 light curve has an unusual two-component shape, where the flux rises with a steep linear gradient for the first few days, followed by a quadratic rise as seen for typical supernovae (SNe) Ia. This "flux excess" relative to canonical SNIa behavior is confirmed in our i-band light curve, and furthermore, SN2018oh is especially blue during the early epochs. The flux excess peaks 2.14{+/-}0.04 days after explosion, has a full width at half maximum (FWHM) of 3.12{+/-}0.04 days, a blackbody temperature of T=17500_-9000_^+11500^K, a peak luminosity of 4.3{+/-}0.2x10^37^erg/s, and a total integrated energy of 1.27{+/-}0.01x10^43^erg. We compare SN2018oh to several models that may provide additional heating at early times, including collision with a companion and a shallow concentration of radioactive nickel. While all of these models generally reproduce the early K2 light curve shape, we slightly favor a companion interaction, at a distance of ~2x10^12^cm based on our early color measurements, although the exact distance depends on the uncertain viewing angle. Additional confirmation of a companion interaction in future modeling and observations of SN2018oh would provide strong support for a single-degenerate progenitor system.2019ApJ...870L...1Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/870/L1CatalogResearchIsServedByTAP VizieR generic servicerelated-toIV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)J/AJ/133/403 : Light curve of 11 type Ia supernovae (Garg+, 2007)J/AJ/135/1598 : Optical spectroscopy of type Ia supernovae (Matheson+, 2008)J/MNRAS/389/1577 : UBVRI absolute magnitudes of Type Ia SNe (Takanashi+, 2008)J/A+A/523/A7 : Light curves of type Ia supernovae in SNLS (Guy+, 2010)J/ApJ/716/712 : HST light curves of six SNe and Union2 (Amanullah+, 2010)J/ApJ/722/566 : Host galaxies of SNeIa in SDSS-II SN survey (Lampeitl+,2010)J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)J/ApJ/749/18 : Swift/UVOT observations of 12 nearby SN-Ia (Brown+, 2012)J/ApJS/200/12 : CfA4: light curves for 94 type Ia SNe (Hicken+, 2012)J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNe Ia (Betoule+, 2014)J/ApJ/795/44 : PS1 SNe Ia (0.02<z<0.7) griz light curves (Rest+, 2014)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJ/813/30 : UV-Optical light curves of SNIa iPTF14bdn (Smitka+, 2015)J/ApJS/220/9 : CfAIR2: NIR light curves of Type Ia SNe (Friedman+, 2015)J/MNRAS/446/3895 : The rising light curves of Type Ia supernovae (Firth+, 2015)J/ApJ/826/144 : Follow-up observations of SNIa ASASSN-14lp (Shappee+, 2016)J/MNRAS/456/2260 : K2 Variability Catalogue II (Armstrong+, 2016)J/ApJ/854/24 : Environmental dependence of SN Ia luminosities (Kim+, 2018)J/ApJ/857/51 : Measuring dark energy data with PS1 SNe. II. (Jones+,2018)J/A+A/627/A174 : Early light curve of SN 2013gy (Holmbo+, 2019)J/ApJ/870/13 : K2 LC alternative analysis of ASASSN-18bt (Shappee+, 2019)http://archive.stsci.edu/missions-and-data/k2 : K2 mission data on MASThttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/870/L1https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/870/L1http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/870/L1https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/870/L1https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/870/L1http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/870/L1GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/870/L1/table2SN 2018oh K2 photometryl_Kpmag3{sigma} upper limit flag on Kpmagmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsYear of the observationstime.epochMJD[58094/58174] Modified julian date of observationdtime.epochdoublePhase[-67/12] Rest-frame phase relative to MJD^peak^_K2_=58162.1dtime.phasefloatTime[-49/30] Time from detection relative to MJD^K2^_detection_=58144.39dtime.epochfloatKpmag[14/22] Apparent Kepler magnitudemagphot.mag;em.optfloate_Kpmag[0.001/0.36]? Uncertainty in Kpmagmagstat.error;phot.magfloatnullable