J/ApJ/834/107ivo://CDS.VizieR/J/ApJ/834/107doi:10.26093/cds/vizier.18340107CDSBlagorodnova N.Kotak R.Polshaw J.Kasliwal M.M.Cao Y.Cody A.M.,Doran G.B.Elias-Rosa N.Fraser M.Fremling C.Gonzalez-Fernandez C.,Harmanen J.Jencson J.Kankare E.Kudritzki R.-P.Kulkarni S.R.,Magnier E.Manulis I.Masci F.J.Mattila S.Nugent P.Ochner P.,Pastorello A.Reynolds T.Smith K.Sollerman J.Taddia F.Terreran G.,Tomasella L.Turatto M.Vreeswijk P.M.Wozniak P.Zaggia S.2017-09-04T08:16:56Z2017-08-01T12:05:39ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomyWide-band photometrysloan-photometrynovaeWe present the results of optical, near-infrared, and mid-infrared observations of M101 OT2015-1 (PSN J14021678+5426205), a luminous red transient in the Pinwheel galaxy (M101), spanning a total of 16 years. The light curve showed two distinct peaks with absolute magnitudes M_r_<=-12.4 and M_r_~-12, on 2014 November 11 and 2015 February 17, respectively. The spectral energy distributions during the second maximum show a cool outburst temperature of ~3700K and low expansion velocities (~-300km/s) for the HI, CaII, BaII, and KI lines. From archival data spanning 15-8 years before the outburst, we find a single source consistent with the optically discovered transient, which we attribute to being the progenitor; it has properties consistent with being an F-type yellow supergiant with L~8.7x10^4^L_{sun}_, T_eff_~7000K, and an estimated mass of M1=18+/-1M_{sun}_. This star has likely just finished the H-burning phase in the core, started expanding, and is now crossing the Hertzsprung gap. Based on the combination of observed properties, we argue that the progenitor is a binary system, with the more evolved system overfilling the Roche lobe. Comparison with binary evolution models suggests that the outburst was an extremely rare phenomenon, likely associated with the ejection of the common envelope of a massive star. The initial mass of the primary fills the gap between the merger candidates V838 Mon (5-10M_{sun}_) and NGC 4490-OT (30M_{sun}_).2017ApJ...834..107Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/834/107CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)J/ApJ/682/1205 : Fast transients in the Fornax cluster (Rau+, 2008)J/ApJ/705/1364 : MIR catalog of point sources in M33 (Thompson+, 2009)J/ApJ/715/1094 : Census of self-obscured massive stars (Khan+, 2010)J/ApJ/733/124 : Cepheids in M101 observed with HST (Shappee+, 2011)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)J/MNRAS/433/1312 : SN2009ip UBVRI, UVOT and JHK light curves (Fraser+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/834/107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/834/107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/834/107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/834/107https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/834/107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/834/107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap2.040811542443644e-19 6.090060298487514e-19InfraredOpticaldefaultJ/ApJ/834/107/table1Historic photometric measurements of M101-OT2015-1l_VmagLimit flag on Vmagmeta.code.errorcharRefReference (1)meta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhasedtime.phasefloatMJDModified Julian Date; MJD-50000dtime.epochfloatTelTelescope usedinstr.setupcharUmag[20.3/21.3]? U band magnitudemagphot.mag;em.opt.Ufloatnullablee_Umag[0.02/0.2]? Uncertainty in Umagmagstat.error;phot.mag;em.opt.UfloatnullableBmag[18.8/22]? B band magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag[0.02/0.3]? Uncertainty in Bmagmagstat.error;phot.mag;em.opt.BfloatnullableVmag[16.3/21.9]? V band magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag[0.02/0.4]? Uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatnullableRmag[16.7/21.2]? R band magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag[0.02/0.2]? Uncertainty in Rmagmagstat.error;phot.mag;em.opt.Rfloatnullableumag[21.7/23.1]? SDSS u band magnitudemagphot.mag;em.opt.Ufloatnullablee_umag[0.1/0.5]? Uncertainty in umagmagstat.error;phot.mag;em.opt.Ufloatnullablegmag[20.4/21.8]? SDSS g band magnitudemagphot.mag;em.opt.Bfloatnullablee_gmag[0.07/0.4]? Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bfloatnullablermag[19.7/21.9]? SDSS r band magnitudemagphot.mag;em.opt.Rfloatnullablee_rmag[0.04/0.3]? Uncertainty in rmagmagstat.error;phot.mag;em.opt.Rfloatnullableimag[19.7/21.5]? SDSS i band magnitudemagphot.mag;em.opt.Ifloatnullablee_imag[0.06/0.5]? Uncertainty in imagmagstat.error;phot.mag;em.opt.Ifloatnullablezmag[19.8/22]? SDSS z band magnitudemagphot.mag;em.opt.Ifloatnullablee_zmag[0.04/0.6]? Uncertainty in zmagmagstat.error;phot.mag;em.opt.Ifloatnullableymag[19.5/20.4]? y band magnitudemagphot.mag;em.IR.Jfloatnullablee_ymag[0.1/0.3]? Uncertainty in ymagmagstat.error;phot.mag;em.opt.Vfloatnullableunfmag[16.5/18]? Unfiltered magnitudemagphot.mag;em.optfloatnullablee_unfmag[0.3]? Uncertainty in unfmagmagstat.error;phot.magfloatnullableJ/ApJ/834/107/table2Post-discovery photometric measurements of M101-OT2015-1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhasedtime.phasefloatMJDModified Julian Date; MJD-50000dtime.epochfloatTelTelescope used (LT, NOT, SAI-2.5m, SAI-6m or Keck)instr.setupcharUmag[19.91]? U band magnitudemagphot.mag;em.opt.Ufloatnullablee_Umag[0.21]? Uncertainty in Umagmagstat.error;phot.mag;em.opt.UfloatnullableBmag[19/22.5]? B band magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag[0/0.6]? Uncertainty in Bmagmagstat.error;phot.mag;em.opt.BfloatnullableVmag[17.6/21]? V band magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag[0.02/0.3]? Uncertainty in Vmagmagstat.error;phot.mag;em.opt.Vfloatnullablel_RmagLimit flag on Rmagmeta.code.errorcharRmag[16.8/23]? R band magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag[0.01/0.5]? Uncertainty in Rmagmagstat.error;phot.mag;em.opt.Rfloatnullablel_ImagLimit flag on Imagmeta.code.errorcharImag[16.3/25]? I band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag[0.03/0.2]? Uncertainty in Imagmagstat.error;phot.mag;em.opt.Ifloatnullablegmag[19/22.2]? SDSS g band magnitudemagphot.mag;em.opt.Bfloatnullablee_gmag[0.06/0.4]? Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bfloatnullablermag[17.7/23.5]? SDSS r band magnitudemagphot.mag;em.opt.Rfloatnullablee_rmag[0.03/0.6]? Uncertainty in rmagmagstat.error;phot.mag;em.opt.Rfloatnullableimag[17.2/21.8]? SDSS i band magnitudemagphot.mag;em.opt.Ifloatnullablee_imag[0.02/0.3]? Uncertainty in imagmagstat.error;phot.mag;em.opt.Ifloatnullablezmag[16.8/19.7]? SDSS z band magnitudemagphot.mag;em.opt.Ifloatnullablee_zmag[0.01/0.07]? Uncertainty in zmagmagstat.error;phot.mag;em.opt.IfloatnullableRefReference (1)meta.ref;pos.framecharJ/ApJ/834/107/table3iPTF follow-up data of M101-OT2015-1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPhasePhasedtime.phasefloatMJDModified Julian Date; MJD-50000dtime.epochfloatTelTelescope used (PTFP48 or PTFP60)instr.setupchargmag[18.4/20.9]? The g band magnitudemagphot.mag;em.opt.Bfloatnullablee_gmag[0.01/0.2]? Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bfloatnullablermag[16.6/20.5]? The r band magnitudemagphot.mag;em.opt.Rfloatnullablee_rmag[0.03/0.4]? Uncertainty in rmagmagstat.error;phot.mag;em.opt.Rfloatnullableimag[16.6/20.6]? The i band magnitudemagphot.mag;em.opt.Ifloatnullablee_imag[0.01/0.2]? Uncertainty in imagmagstat.error;phot.mag;em.opt.Ifloatnullable