J/AJ/171/17ivo://CDS.VizieR/J/AJ/171/17CDSAftab N.Zhang X.Walker S.Di Cicco D.Mittelman D.R.Gupta S.,Saydjari A.K.Putman M.Schiminovich D.2026-08-19T08:04:26Z2026-08-19T08:49:20ZCDS support team

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

cds-question@unistra.frsurveysvisible-astronomynarrow-band-photometryThe Mittelman-di Cicco-Walker (MDW) H{alpha} Sky Survey is an autonomously operated all-sky narrowband (3nm) H{alpha} imaging survey. The survey was founded by amateur astronomers, and the northern sky (decl. >=0{deg}) is presented here in its second stage of refinement for academic use. Each 3.6 deg^2^ MDW field has 12 20 minutes individual exposures with a pixel scale of 3.2", a typical point-spread function of 6", and a stack point-source depth of 16-17 mag. The northern MDW Survey Data Release 1 (DR1) includes calibrated mean and individual images, star-removed mean fields, and point-source catalogs for all images matched to Data Release 1 of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) and the INT Galactic Plane Survey. (All DR1 components are available at https://mdw.astro.columbia.edu. The catalogs are also made available in the AAS Journals Zenodo repository: doi:10.5281/zenodo.17307324.) Our initial study of H{alpha} filament widths finds a typical FWHM of 30"-45" in the Lyra region. The matched catalogs (with a median match distance of ~0.5"), combined with our distinctive narrowband photometry, are also used to identify H{alpha} variable and excess sources. These initial studies highlight some of the many scientific uses of the MDW H{alpha} survey.2026AJ....171...17Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/171/17CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/165 : IGAPS. merged IPHAS and UVEX of northern Galactic planeII/389 : The Pan-STARRS release 1 (PS1) Survey - DR2 (Magnier+, 2025)https://mdw.astro.columbia.edu/index.html : Columbia University MDW home pagehttps://www.mdwskysurvey.org : MDW Sky Survey home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/171/17https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/171/17http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/171/17https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/171/17https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/171/17http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/171/17GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/171/17/mdw_dr1 (MDW catalog sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/171/17/mdw_dr1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/171/17/mdw_dr1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/171/17/mdw_dr1?GETtext/xml+votable180.050000true97.9988705742678-0.19210749844110.0055555555555555560/0-11 6/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/171/17?format=asciiOpticaldefaultJ/AJ/171/17/mdw_dr1MDW catalog sourcesRAJ2000The MDW source's J2000 Right Ascension (RAdeg)degpos.eq.ra;meta.mainindexedDEJ2000The MDW source's J2000 Declination (DEdeg)degpos.eq.dec;meta.mainindexedGLONThe MDW source's Galactic longitude (GLON)degpos.galactic.lonGLATThe MDW source's Galactic longitude (GLAT)degpos.galactic.latdoubleHamagThe MDW source's calibrated H-alpha AB magnitude (Ha_mag)magphot.flux;em.line.HalphadoubleHainstmagThe MDW source's instrument H-alpha magnitude, calculated from Ha_instr_flux (Ha_instr_mag)magphot.flux;em.line.HalphadoubleHainstFluxThe MDW source's instrument flux, measured via PSF photometry (Ha_instr_flux)ctphot.countdoublefittedFWHMThe FWHM of this source, fitted to an exponential per DR1 paper (fitted_fwhm) (1)pixmeta.bibdoubleFieldThe field number this source is found in (field) (2)meta.id;obs.fieldinitialFWHMThe initial FWHM of this source (initial_fwhm)pixphys.angSizedoubleFileNameName of the mean-combined FITS file this source is found in (file_name)meta.id;meta.fitscharRAPdeg[0/360] The matched PanSTARRS source's J2000 Right Ascension (ps1_RAJ2000)degpos.eq.raDEPdeg[-90/90] The matched PanSTARRS source's J2000 Declination (ps1_DEJ2000)degpos.eq.decps1objIDThe matched PanSTARRS object ID (ps1_objID)meta.idPS1gmagThe matched PanSTARRS source's g AB magnitude (ps1_g_mag)magphot.mag;em.opt.BdoublePS1rmagThe matched PanSTARRS source's r AB magnitude (ps1_r_mag)magphot.mag;em.opt.RdoublePS1imagThe matched PanSTARRS source's i AB magnitude (ps1_i_mag)magphot.mag;em.opt.IdoubleNPS1nearbyThe number of nearby PanSTARRS objects within 6 arcsec of this MDW source (n_ps1_nearby)meta.numberRAIdeg[0/360]? The matched IGAPS source's J2000 Right Ascension (igaps_RAJ2000)degpos.eq.ranullableDEIdeg[-90/90]? The matched IGAPS source's J2000 Declination (igaps_DEJ2000)degpos.eq.decnullableIGAPSNameThe matched IGAPS source's name (igaps_name)meta.idcharIGAPSrmag? The matched IGAPS source's r AB magnitude (igaps_r_mag)magphot.mag;em.opt.RdoublenullableIGAPSimag? The matched IGAPS source's i AB magnitude (igaps_i_mag)magphot.mag;em.opt.IdoublenullableIGAPSgmag? The matched IGAPS source's g AB magnitude (igaps_g_mag)magphot.mag;em.opt.BdoublenullableIGAPSHamag? The matched IGAPS source's H-alpha AB magnitude (igaps_Ha_mag)magphot.flux;em.line.HalphadoublenullableMDWxThe MDW source centroid's x coordinate (mdw_x)pos.cartesian.x;instr.detdoubleMDWyThe MDW source centroid's y coordinate (mdw_y)pos.cartesian.y;instr.detdoubleMDW-PS1-sep2d? The 2D separation distance between the MDW source and the matched PanSTARRS source (mdw_ps1_sep2d)arcsecpos.angDistancedoublenullablePS1-IGAPS-sep2d? The 2D separation distance between the matched PanSTARRS and IGAPS sources (ps1_igaps_sep2d)arcsecpos.angDistancedoublenullable