J/A+A/676/A107ivo://CDS.VizieR/J/A+A/676/A107doi:10.26093/cds/vizier.36760107CDSFedriani R.Caratti o Garatti A.Cesaroni R.Tan J.C.Stecklum B.,Moscadelli L.Koutoulaki M.Cosentino G.Whittle M.2024-11-06T20:05:17Z2023-08-17T08:12:14ZCDS support team

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

cds-question@unistra.frinfrared-sourcesyoung-stellar-objectsMassive stars have an impact on their surroundings from early in their formation until the end of their lives. However, very little is known about their formation. Episodic accretion may play a crucial role in the process, but only a handful of observations have reported such events occurring in massive protostars. We aim to investigate the outburst event from the high-mass star-forming region S255IR where the protostar NIRS3 recently underwent an accretion outburst. We follow the evolution of this source both in photometry and morphology of its surroundings. We performed near infrared adaptive optics observations on the S255IR central region using the Large Binocular Telescope in the Ks broadband as well as the H_2_ and Br{gamma} narrow-band filters with an angular resolution of ~0.06arcsec, close to the diffraction limit. We discovered a new near infrared knot north-east of NIRS3 that we interpret as a jet knot that was ejected during the last accretion outburst and observed in the radio regime as part of a follow-up after the outburst. We measured a mean tangential velocity for this knot of 450+/-50km/s. We analysed the continuum-subtracted images from H_2_, which traces jet-shocked emission, and Br{gamma}, which traces scattered light from a combination of accretion activity and UV radiation from the central massive protostar. We observed a significant decrease in flux at the location of NIRS3, with K=13.48mag being the absolute minimum in the historic series. Our observations strongly suggest a scenario where the episodic accretion is followed by an episodic ejection response in the near infrared, as was seen in the earlier radio follow-up. The ~2um photometry from the past 30 years suggests that NIRS3 might have undergone another outburst in the late 1980s, making it the first massive protostar with such evidence observed in the near infrared.2023A&A...676A.107Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/676/A107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/676/A107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/676/A107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/676/A107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/676/A107https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/676/A107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/676/A107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/676/A107/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/676/A107/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/676/A107/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/676/A107/list?GETtext/xml+votable180.050000true93.2261217.989510.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/676/A1076/23969https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/676/A107?format=asciiInfrareddefaultJ/A+A/676/A107/listList of fits imagesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscale[0.0149] Scale of the imagearcsec/pixinstr.scalefloatNx[2048] Number of pixels along X-axismeta.numberintNy[2048] Number of pixels along Y-axismeta.numberintObs.dateObservation datestime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar