J/ApJ/922/5ivo://CDS.VizieR/J/ApJ/922/5doi:10.26093/cds/vizier.19220005CDSLau R.M.Tinyanont S.Hankins M.J.Ashley M.C.B.De K.,Filippenko A.V.Hillenbrand L.A.Kasliwal M.M.Mauerhan J.C.,Moffat A.F.J.Moore A.M.Smith N.Soon J.Soria R.Travouillon T.,van der Hucht K.A.Williams P.M.Zheng W.2023-08-25T12:11:35Z2023-04-11T16:43:43ZCDS support team

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

cds-question@unistra.frwolf-rayet-starsinfrared-photometryvisible-astronomybroad-band-photometryWe present optical and infrared (IR) light curves of NaSt1, also known as Wolf-Rayet 122, with observations from Palomar Gattini-IR (PGIR), the Zwicky Transient Facility (ZTF), the Katzman Automatic Imaging Telescope, the Asteroid Terrestrial-impact Last Alert System, and the All-Sky Automated Survey for Supernovae (ASAS-SN). We identify a P=309.7+/-0.7day photometric period from the optical and IR light curves that reveal periodic, sinusoidal variability between 2014 July and 2021 July. We also present historical IR light curves taken between 1983 July and 1989 May, which show variability consistent with the period of the present-day light curves. In the past, NaSt1 was brighter in the J band with larger variability amplitudes than the present-day PGIR values, suggesting that NaSt1 exhibits variability on longer (>~decade) timescales. Sinusoidal fits to the recent optical and IR light curves show that the amplitude of NaSt1's variability differs at various wavelengths and also reveal significant phase offsets of 17.0+/-2.5day between the ZTF r and PGIR J light curves. We interpret the 310 day photometric period from NaSt1 as the orbital period of an enshrouded massive binary. We suggest that the photometric variability of NaSt1 may arise from variations in the line-of-sight optical depth toward circumstellar optical/IR-emitting regions throughout its orbit due to colliding-wind dust formation. We speculate that past mass transfer in NaSt1 may have been triggered by Roche-lobe overflow (RLOF) during an eruptive phase of an Ofpe/WN9 star. Lastly, we argue that NaSt1 is no longer undergoing RLOF mass transfer.2021ApJ...922....5Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/922/5CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/183 : UBVRI Photometric Standards (Landolt 1992)J/A+AS/119/547 : IR photometry of ESO calibration stars (van der Bliek+ 1996)J/AJ/129/2018 : RXTE scaled fluxes of eta Car (Corcoran+, 2005)J/A+A/504/959 : Amplitudes of single-mode Cepheids (Klagyivik+, 2009)J/ApJS/190/418 : Light curves for 165 SNe (Ganeshalingam+, 2010)J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/MNRAS/465/2432 : MiMeS magnetic analysis of O-type stars (Grunhut+, 2017)J/A+A/615/A78 : Spectral models for binary products (Goetberg+, 2018)J/AJ/156/241 : Catalog of variable stars measured by ATLAS (Heinze+, 2018)J/A+A/627/A175 : GLOSTAR. Radio Source Catalogue I (Medina+ 2019)J/MNRAS/488/1282 : Variable dust emission by WC type WR* (Williams, 2019)J/ApJ/901/L7 : NIR obs. of the Gal. magnetar SGR1935+215 (De+, 2020)J/ApJ/893/11 : Massive star variability in M31 from iPTF (Soraisam+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/922/5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/922/5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/922/5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/922/5https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/922/5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/922/5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap1.398457827073138e-19 1.7798557115773645e-19OpticalInfrareddefaultJ/ApJ/922/5/table1KAIT, ATLAS, ASAS-SN, ZTF, and PGIR photometry of NaSt1VmagA[14.3/14.51]? Apparent ASAS-SN V band Vega magnitudemagphot.mag;em.opt.Vfloatnullablee_VmagA[0.016/0.03]? Uncertainty in VmagAmagstat.error;phot.magfloatnullablermagZ[12.7/13]? Apparent ZTF r band Vega magnitudemagphot.mag;em.opt.Rfloatnullablee_rmagZ[0.02/0.03]? Uncertainty in rmagZmagstat.error;phot.magfloatnullableRmagK[12.6/13]? Apparent KAIT R band Vega magnitudemagphot.mag;em.opt.Rfloatnullablee_RmagK[0.015]? Uncertainty in RmagKmagstat.error;phot.magfloatnullableomagA[12.44/12.8]? Apparent 'orange' band Vega magnitudemagphot.mag;em.optfloatnullablee_omagA[0.002/0.06]? Uncertainty in omagAmagstat.error;phot.magfloatnullableClmagK[12.83/13.1]? Apparent KAIT clear band Vega magnitudemagphot.mag;em.opt.RfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[56818.4/59404.4] Modified Julian Datedtime.epochdoubleBmagK[16.13/16.3]? Apparent KAIT B band Vega magnitudemagphot.mag;em.opt.Bfloatnullablee_BmagK[0.036/0.2]? Uncertainty in BmagKmagstat.error;phot.magfloatnullablegmagZ[15.25/15.5]? Apparent ZTF g band Vega magnitudemagphot.mag;em.opt.Bfloatnullablee_gmagZ[0.03/0.04]? Uncertainty in gmagZmagstat.error;phot.magfloatnullablecmagA[14.27/14.5]? Apparent ATLAS 'cyan' band Vega magnitudemagphot.mag;em.opt.Bfloatnullablee_cmagA[0.004/0.03]? Uncertainty in cmagAmagstat.error;phot.magfloatnullableVmagK[13.94/14.11]? Apparent KAIT V band Vega magnitudemagphot.mag;em.opt.Vfloatnullablee_VmagK[0.023/0.025]? Uncertainty in VmagKmagstat.error;phot.magdoublenullablee_ClmagK[0.004/0.03]? Uncertainty in ClmagKmagstat.error;phot.magfloatnullableImagK[12.23/12.4]? Apparent KAIT I band Vega magnitudemagphot.mag;em.opt.Ifloatnullablee_ImagK[0.03/0.04]? Uncertainty in ImagKmagstat.error;phot.magfloatnullableJmagP[9.43/9.8]? Apparent PGIR J band Vega magnitudemagphot.mag;em.IR.Jfloatnullablee_JmagP[0.007/0.03]? Uncertainty in JmagPmagstat.error;phot.magfloatnullable