alerce_tap.lsst_ivo://x-unregistred/alerce_tap/multisurvey_lowercase/lsst_detectionALeRCE (Automatic Learning for the Rapid Classification of Events)ALeRCE Teamhttps://tap.alerce.online/favicon.png2026-04-11T22:13:50ZALeRCE Team

Beauchef 851, Edificio Norte, piso 6. Santiago, Chile.

alerce.broker@gmail.comastronomy, objectssurveystransientstime-series Individual LSST Difference Image Analysis sources, containing detailed measurements from difference imaging including PSF photometry, aperture photometry, trail and dipole fitting for moving objects, shape moments, forced photometry on science and template images, and extensive quality flags for pixels and measurements.http://tap.alerce.online/tableinfo/alerce_tap.lsst_detectionalerce_tap Multi-survey astronomical object catalog containing astrometric and statistical information from multiple surveys. This table provides aggregated properties for astronomical objects including position, detection statistics, and temporal coverage.alerce_tap.lsst_detection Individual LSST Difference Image Analysis sources, containing detailed measurements from difference imaging including PSF photometry, aperture photometry, trail and dipole fitting for moving objects, shape moments, forced photometry on science and template images, and extensive quality flags for pixels and measurements.oidObject identifiermeta.id;srclongindexedprimarysidSurvey identifiermeta.idshortmeasurement_idUnique identifier of this DiaSourcemeta.idlongindexedprimaryparentdiasourceidId of the parent diaSource this diaSource has been deblended from, if anymeta.idlongnullablevisitVisit numberobs.fieldlongdetectorDetector numberinstr.detintdiaobjectidId of the diaObject this source was associated with, if any. If not, it is set to NULL (each diaSource will be associated with either a diaObject or ssObject)meta.idlongnullablessobjectidId of the ssObject this source was associated with, if any. If not, it is set to NULL (each diaSource will be associated with either a diaObject or ssObject)meta.idlongnullableraerrUncertainty of radegstat.error;pos.eq.rafloatnullabledecerrUncertainty of decdegstat.error;pos.eq.decfloatnullablera_dec_covCovariance between ra and decdeg**2stat.covariance;pos.eqfloatnullablexx position computed by a centroiding algorithmpixpos.cartesian.xfloatxerrUncertainty of xpixstat.error;pos.cartesian.xfloatnullableyy position computed by a centroiding algorithmpixpos.cartesian.yfloatyerrUncertainty of ypixstat.error;pos.cartesian.yfloatnullablecentroid_flagGeneral centroid algorithm failure flag; set if anything went wrong when fitting the centroid. Another centroid flag field should also be set to provide more informationmeta.code.qualbooleannullableapfluxFlux in a 12 pixel radius aperture on the difference imagephot.fluxfloatnullableapfluxerrEstimated uncertainty of apFluxstat.error;phot.fluxfloatnullableapflux_flagGeneral aperture flux algorithm failure flag; set if anything went wrong when measuring aperture fluxes. Another apFlux flag field should also be set to provide more informationmeta.code.qualbooleannullableapflux_flag_aperturetruncatedAperture did not fit within measurement imagemeta.code.qualbooleannullableisnegativeSource was detected as significantly negativemeta.codebooleannullablesnrThe signal-to-noise ratio at which this source was detected in the difference imagestat.snrfloatnullablepsffluxFlux for Point Source model. Note this actually measures the flux difference between the template and the visit imagephot.fluxfloatnullablepsffluxerrUncertainty of psfFluxstat.error;phot.fluxfloatnullablepsflnlNatural log likelihood of the observed data given the point source modelstat.likelihoodfloatnullablepsfchi2Chi^2 statistic of the point source model fitstat.fit.chi2floatnullablepsfndataThe number of data points (pixels) used to fit the point source modelmeta.numberintnullablepsfflux_flagFailure to derive linear least-squares fit of psf model. Another psfFlux flag field should also be set to provide more informationmeta.code.qualbooleannullablepsfflux_flag_edgeObject was too close to the edge of the image to use the full PSF modelmeta.code.qualbooleannullablepsfflux_flag_nogoodpixelsNot enough non-rejected pixels in data to attempt the fitmeta.code.qualbooleannullabletrailfluxFlux for a trailed source model. Note this actually measures the flux difference between the template and the visit imagephot.fluxfloatnullabletrailfluxerrUncertainty of trailFluxstat.error;phot.fluxfloatnullabletrailraRight ascension coordinate of centroid for trailed source modeldegpos.eq.radoublenullabletrailraerrUncertainty of trailRadegstat.error;pos.eq.rafloatnullabletraildecDeclination coordinate of centroid for trailed source modeldegpos.eq.decdoublenullabletraildecerrUncertainty of trailDecdegstat.error;pos.eq.decfloatnullabletraillengthMaximum likelihood fit of trail lengtharcsecphys.angSizefloatnullabletraillengtherrUncertainty of trailLengtharcsecstat.errorfloatnullabletrailangleMaximum likelihood fit of the angle between the meridian through the centroid and the trail direction (bearing)degpos.posAngfloatnullabletrailangleerrUncertainty of trailAngledegstat.errorfloatnullabletrailchi2Chi^2 statistic of the trailed source model fitstat.fit.chi2floatnullabletrailndataThe number of data points (pixels) used to fit the trailed source modelmeta.numberintnullabletrail_flag_edgeThis flag is set if a trailed source extends onto or past edge pixelsmeta.code.qualbooleannullabledipolemeanfluxMaximum likelihood value for the mean absolute flux of the two lobes for a dipole modelphot.fluxfloatnullabledipolemeanfluxerrUncertainty of dipoleMeanFluxstat.error;phot.fluxfloatnullabledipolefluxdiffMaximum likelihood value for the difference of absolute fluxes of the two lobes for a dipole modelphot.fluxfloatnullabledipolefluxdifferrUncertainty of dipoleFluxDiffstat.error;phot.fluxfloatnullabledipolelengthMaximum likelihood value for the lobe separation in dipole modelarcsecphys.angSizefloatnullabledipoleangleMaximum likelihood fit of the angle between the meridian through the centroid and the dipole direction (bearing, from negative to positive lobe)degpos.posAngfloatnullabledipolechi2Chi^2 statistic of the model fitstat.fit.chi2floatnullabledipolendataThe number of data points (pixels) used to fit the modelmeta.numberintnullablesciencefluxForced photometry flux for a point source model measured on the visit image centered at DiaSource positionphot.fluxfloatnullablesciencefluxerrEstimated uncertainty of scienceFluxstat.error;phot.fluxfloatnullableforced_psfflux_flagForced PSF photometry on science image failed. Another forced_PsfFlux flag field should also be set to provide more informationmeta.code.qualbooleannullableforced_psfflux_flag_edgeForced PSF flux on science image was too close to the edge of the image to use the full PSF modelmeta.code.qualbooleannullableforced_psfflux_flag_nogoodpixelsForced PSF flux not enough non-rejected pixels in data to attempt the fitmeta.code.qualbooleannullabletemplatefluxForced photometry flux for a point source model measured on the template image centered at the DiaObject positionphot.fluxfloatnullabletemplatefluxerrUncertainty of templateFluxstat.error;phot.fluxfloatnullableixxAdaptive second moment of the source intensitynJy.arcsec**2phys.sizefloatnullableiyyAdaptive second moment of the source intensitynJy.arcsec**2phys.sizefloatnullableixyAdaptive second moment of the source intensitynJy.arcsec**2phys.sizefloatnullableixxpsfAdaptive second moment for the PSFnJy.arcsec**2phys.sizefloatnullableiyypsfAdaptive second moment for the PSFnJy.arcsec**2phys.sizefloatnullableixypsfAdaptive second moment for the PSFnJy.arcsec**2phys.sizefloatnullableshape_flagGeneral source shape algorithm failure flag; set if anything went wrong when measuring the shape. Another shape flag field should also be set to provide more informationmeta.code.qualbooleannullableshape_flag_no_pixelsNo pixels to measure shapemeta.code.qualbooleannullableshape_flag_not_containedCenter not contained in footprint bounding boxmeta.code.qualbooleannullableshape_flag_parent_sourceThis source is a parent source; we should only be measuring on deblended children in difference imagingmeta.code.qualbooleannullableextendednessA measure of extendedness, computed by comparing an object's moment-based traced radius to the PSF moments. extendedness = 1 implies a high degree of confidence that the source is extended. extendedness = 0 implies a high degree of confidence that the source is point-likesrc.class.starGalaxyfloatnullablereliabilityProbability (0-1) that the diaSource is astrophysical, derived from a machine learning modelstat.probabilityfloatnullableisdipoleSource well fit by a dipolemeta.codebooleannullabledipolefitattemptedAttempted to fit a dipole model to this sourcemeta.codebooleannullabletimeprocessedmjdtaiTime when the image was processed and this DiaSource record was generated, expressed as Modified Julian Date, International Atomic Timedtime.processingdoubletimewithdrawnmjdtaiTime when this record was marked invalid, expressed as Modified Julian Date, International Atomic Timedtime.processingdoublenullablebboxsizeSize of the square bounding box that fully contains the detection footprintpixphys.angSizeintnullablepixelflagsGeneral pixel flags failure; set if anything went wrong when setting pixels flags from this footprint's mask. This implies that some pixelFlags for this source may be incorrectly set to Falsemeta.code.qualbooleannullablepixelflags_badBad pixel in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_crCosmic ray in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_crcenterCosmic ray in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_edgeSome of the source footprint is outside usable exposure region (masked EDGE or centroid off image)meta.code.qualbooleannullablepixelflags_nodataNO_DATA pixel in the source footprintmeta.code.qualbooleannullablepixelflags_nodatacenterNO_DATA pixel in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_interpolatedInterpolated pixel in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_interpolatedcenterInterpolated pixel in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_offimageDiaSource center is off imagemeta.code.qualbooleannullablepixelflags_saturatedSaturated pixel in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_saturatedcenterSaturated pixel in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_suspectDiaSource's footprint includes suspect pixelsmeta.code.qualbooleannullablepixelflags_suspectcenterSuspect pixel in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_streakStreak in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_streakcenterStreak in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_injectedInjection in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_injectedcenterInjection in the 3x3 region around the centroidmeta.code.qualbooleannullablepixelflags_injected_templateTemplate injection in the DiaSource footprintmeta.code.qualbooleannullablepixelflags_injected_templatecenterTemplate injection in the 3x3 region around the centroidmeta.code.qualbooleannullableglint_trailThis flag is set if the source is part of a glint trailmeta.codebooleannullablehas_stampHas image stamp flagmeta.codebooleannullablecreated_dateDate record was createdtime.creationcharnullable