alerce_tap.ztf_rivo://x-unregistred/alerce_tap/multisurvey_lowercase/ztf_referenceALeRCE (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 Information about ZTF reference (template) images used for difference imaging, including properties of the nearest catalog source, temporal coverage of the reference image stack, and field/CCD identifiers.http://tap.alerce.online/tableinfo/alerce_tap.ztf_referencealerce_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.ztf_reference Information about ZTF reference (template) images used for difference imaging, including properties of the nearest catalog source, temporal coverage of the reference image stack, and field/CCD identifiers.oidUnique identifier for this objectmeta.id;srclongindexedprimaryrfidProcessing ID for reference image to facilitate archive retrievalmeta.idlongindexedprimarymeasurement_idUnique identifier for the first detection associated with this reference imagemeta.idlongbandFilter ID: 1=g, 2=r, 3=iinstr.bandpassintnullablercidReadout channel ID [00 .. 63]instr.detintnullablefieldZTF field IDobs.fieldintnullablemagnrMagnitude of nearest source in reference image PSF-catalog within 30 arcsecmagphot.magfloatnullablesigmagnr1-sigma uncertainty in magnr within 30 arcsecmagstat.error;phot.magfloatnullablechinrDAOPhot chi parameter of nearest source in reference image PSF-catalog within 30 arcsecstat.fit.chi2floatnullablesharpnrDAOPhot sharp parameter of nearest source in reference image PSF-catalog within 30 arcsec (values between -0.13 and 0.1 indicate unresolved sources)stat.valuefloatnullableranrRight ascension of nearest source in reference image PSF-catalog, J2000degpos.eq.ra;meta.maindoubleindexednullabledecnrDeclination of nearest source in reference image PSF-catalog, J2000degpos.eq.dec;meta.maindoubleindexednullablemjdstartrefObservation Modified Julian Date of earliest exposure used to generate reference imagedtime.startdoublenullablemjdendrefObservation Modified Julian Date of latest exposure used to generate reference imagedtime.enddoublenullablenframesrefNumber of frames (epochal images) used to generate reference imagemeta.numberintnullablecreated_dateDate record was createdtime.creationcharnullable