J/ApJ/743/118ivo://CDS.VizieR/J/ApJ/743/118doi:10.26093/cds/vizier.17430118CDSHumphreys R.M.Bond H.E.Bedin L.R.Bonanos A.Z.Davidson K.,Berto Monard L.A.G.Prieto J.L.Walter F.M.2017-06-30T05:48:52Z2013-06-13T14:58:54ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourcesinfrared-photometryvisible-astronomybroad-band-photometryvariable-starsThe 2008 optical transient in NGC 300 is one of a growing class of intermediate-luminosity transients that brighten several orders of magnitude from a previously optically obscured state. The origin of their eruptions is not understood. Our multi-wavelength photometry and spectroscopy from maximum light to more than a year later provide a record of its post-eruption behavior. We describe its changing spectral energy distribution, the evolution of its absorption- and emission-line spectrum, the development of a bipolar outflow, and the rapid transition from a dense wind to an optically thin ionized wind. In addition to strong, narrow hydrogen lines, the F-type absorption-line spectrum of the transient is characterized by strong CAII and [CAII] emission. The very broad wings of the CAII triplet and the asymmetric [CAII] emission lines are due to strong Thomson scattering in the expanding ejecta. Post-maximum, the hydrogen and CaII lines developed double-peaked emission profiles that we attribute to a bipolar outflow. Between approximately 60 and 100 days after maximum, the F-type absorption spectrum, formed in its dense wind, weakened and the wind became transparent to ionizing radiation. We discuss the probable evolutionary state of the transient and similar objects such as SN 2008S and conclude that they were most likely post-red supergiants or post-asymptotic giant branch stars on a blue loop to warmer temperatures when the eruption occurred. These objects are not luminous blue variables.2011ApJ...743..118Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/743/118CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2013)J/ApJ/715/1094 : Census of self-obscured massive stars (Khan+, 2010)J/ApJ/705/1364 : MIR catalog of point sources in M33 (Thompson+, 2009)J/AJ/128/1167 : ARAUCARIA project : NGC 300 Variables. II (Gieren+, 2004)J/MNRAS/350/679 : BV photometry of NGC 300 variables (Mennickent+, 2004)J/PASP/114/298 : BVI photometry in NGC 300 (Pietrzynski+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/743/118https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/743/118http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/743/118https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/743/118https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/743/118http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/743/118GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap7.952274030004205e-20 4.920466254354166e-19OpticalInfrareddefaultJ/ApJ/743/118/table6SMARTS 1.3-m ANDICAM and Bronberg photometry of NGC 300 OT2008-1DayElapsed daysdtime.intervalfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date; HJD-2400000dtime.epochdoubleBmag? The B band magnitude (1)magphot.mag;em.opt.BfloatnullableVmag? The V band magnitude (1)magphot.mag;em.opt.VfloatnullableRmag? The R band magnitude (1)magphot.mag;em.opt.RfloatnullableImag? The I band magnitude (1)magphot.mag;em.opt.IfloatnullableJmag? The J band magnitude (1)magphot.mag;em.IR.JfloatnullableHmag? The H band magnitude (1)magphot.mag;em.IR.HfloatnullableKmag? The K band magnitude (1)magphot.mag;em.IR.Kfloatnullable