J/A+A/626/A69ivo://CDS.VizieR/J/A+A/626/A69doi:10.26093/cds/vizier.36260069CDSGoettgens F.Weilbacher P.M.Roth M.M.Dreizler S.Giesers B.,Husser T.-O.Kamann S.Brinchmann J.Kollatschny W.Monreal-Ibero A.,Schmidt K.B.Wendt M.Wisotzki L.Bacon R.2019-08-06T15:07:55Z2019-06-19T09:03:30ZCDS support team

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

cds-question@unistra.frglobular-star-clusterseclipsing-binary-starsspectroscopyA nova is a cataclysmic event on the surface of a white dwarf in a binary system that increases the overall brightness by several orders of magnitude. Although binary systems with a white dwarf are expected to be overabundant in globular clusters (GCs) compared to the Galaxy, only two novae from Galactic globular clusters have been observed. We present the discovery of an emission nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made with the integral-field spectrograph MUSE. We extract the spectrum of the nebula and use the radial velocity determined from the emission lines to confirm that the nebula is part of NGC 6656. Emission-line ratios are used to determine the electron temperature and density. It is estimated to have a mass of 1 to 17x10^-5^ solar masses. This mass and the emission-line ratios indicate that the nebula is a nova remnant. Its position coincides with the reported location of a 'guest star', an ancient Chinese term for transients, observed in May 48 BCE. With this discovery, this nova may be one of the oldest confirmed extrasolar events recorded in human history.2019A&A...626A..69Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/626/A69CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/626/A69https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/626/A69http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/626/A69https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/626/A69https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/626/A69http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/626/A69GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/626/A69/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/626/A69/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/626/A69/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/626/A69/list?GETtext/xml+votable180.050000true279.10051-23.908360.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/626/A696/28973https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/626/A69?format=asciidefaultJ/A+A/626/A69/listList of fits filesrecnoRecord 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? Scale of the image for the datacubearcsec/pixinstr.scalefloatnullableNxNumber of pixels along X-axismeta.numberintNy? Number of pixels along Y-axis for the datacubemeta.numberintnullableNz? Number of slices for the datacubemeta.numberintnullablebAWAVLower value of wavelength interval0.1nmem.wlfloatBAWAVUpper value of wavelength interval0.1nmem.wlfloatdAWAVWavelength resolution0.1nmspect.resolutionfloatsizeSize 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.urlcharspShow the spectrummeta.ref.urlchar