Table Description:
ZTF forced photometry measurements at known object positions, including magnitudes with and without host galaxy corrections, image quality metrics (seeing, background, zero point), reference source properties, and processing status flags.
This table is available for ADQL queries and through the TAP endpoint.
Resource Description:
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.
For a list of all services and tables belonging to this table's resource, see Information on resource 'ALeRCE Multi-Survey Object Catalog'
To cite the table as such, we suggest the following BibTeX entry:
@MISC{vo:alerce_tap_ztf_f,
year=2026,
title={{ZTF} Forced Photometry},
author={{ALeRCE} Team},
url={http://tap.alerce.online/tableinfo/alerce_tap.ztf_forced_photometry},
howpublished={{VO} resource provided by the {ALeRCE} {TAP} service}
}
Sorted alphabetically. [Sort by DB column index]
| Name | Table Head | Description | Unit | UCD |
|---|---|---|---|---|
| adpctdif1 | Adpctdif1 | Adaptive percentile difference 1 | N/A | stat.value |
| adpctdif2 | Adpctdif2 | Adaptive percentile difference 2 | N/A | stat.value |
| chinr | Chinr | Chi of nearest source | N/A | stat.fit.chi2 |
| clrcoeff | Clrcoeff | Color coefficient | N/A | arith.factor |
| clrcounc | Clrcounc | Color coefficient uncertainty | N/A | stat.error;arith.factor |
| corrected | Corrected | Correction applied flag | N/A | meta.code.qual |
| created_date | Created_date | Date record was created | N/A | time.creation |
| decnr | Decnr | Dec of nearest source | deg | pos.eq.dec |
| diffmaglim | Diffmaglim | Difference image magnitude limit | mag | phot.mag;stat.min |
| distnr | Distnr | Distance to nearest source | arcsec | pos.angDistance |
| dubious | Dubious | Dubious measurement flag | N/A | meta.code.qual |
| e_mag | E_mag | Magnitude error | mag | stat.error;phot.mag |
| e_mag_corr | E_mag_corr | Corrected magnitude error | mag | stat.error;phot.mag;arith.corrected |
| e_mag_corr_ext | E_mag_corr_ext | Extended corrected magnitude error | mag | stat.error;phot.mag |
| exptime | Exptime | Exposure time | s | time.duration;obs.exposure |
| field | Field | Field number | N/A | obs.field |
| isdiffpos | Isdiffpos | Difference image positive flag | N/A | meta.code |
| mag | Mag | Magnitude | mag | phot.mag |
| mag_corr | Mag_corr | Corrected magnitude | mag | phot.mag;arith.corrected |
| magnr | Magnr | Magnitude of nearest source | mag | phot.mag |
| magzpsci | Magzpsci | Magnitude zero point | mag | phot.calib |
| magzpscirms | Magzpscirms | Magnitude zero point RMS | mag | stat.stdev;phot.calib |
| magzpsciunc | Magzpsciunc | Magnitude zero point uncertainty | mag | stat.error;phot.calib |
| measurement_id | Measurement_id | Measurement identifier | N/A | meta.id |
| oid | Oid | Object identifier | N/A | meta.id;src |
| parent_candid | Parent_candid | Parent candidate ID | N/A | meta.id |
| pid | Pid | Processing ID | N/A | meta.id |
| procstatus | Procstatus | Processing status | N/A | meta.code.status |
| programid | Programid | Program ID | N/A | obs.program |
| ranr | Ranr | RA of nearest source | deg | pos.eq.ra |
| rcid | Rcid | Readout channel ID | N/A | instr.det |
| rfid | Rfid | Reference image ID | N/A | meta.id |
| scibckgnd | Scibckgnd | Science image background | N/A | instr.skyLevel |
| sciinpseeing | Sciinpseeing | Science image seeing | arcsec | instr.obsty.seeing |
| scisigpix | Scisigpix | Science image sigma per pixel | N/A | stat.stdev;instr.pixel |
| sharpnr | Sharpnr | Sharpness of nearest source | N/A | stat.value |
| sid | Sid | Survey identifier | N/A | meta.id |
| sigmagnr | Sigmagnr | Magnitude error of nearest source | mag | stat.error;phot.mag |
Columns that are parts of indices are marked like this.
VO nerds may sometimes need VOResource XML for this table.