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 by DB column index. [Sort alphabetically]
| Name | Table Head | Description | Unit | UCD |
|---|---|---|---|---|
| oid | Oid | Object identifier | N/A | meta.id;src |
| sid | Sid | Survey identifier | N/A | meta.id |
| measurement_id | Measurement_id | Measurement identifier | N/A | meta.id |
| pid | Pid | Processing ID | N/A | meta.id |
| mag | Mag | Magnitude | mag | phot.mag |
| e_mag | E_mag | Magnitude error | mag | stat.error;phot.mag |
| mag_corr | Mag_corr | Corrected magnitude | mag | phot.mag;arith.corrected |
| 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 |
| isdiffpos | Isdiffpos | Difference image positive flag | N/A | meta.code |
| corrected | Corrected | Correction applied flag | N/A | meta.code.qual |
| dubious | Dubious | Dubious measurement flag | N/A | meta.code.qual |
| parent_candid | Parent_candid | Parent candidate ID | N/A | meta.id |
| field | Field | Field number | N/A | obs.field |
| rcid | Rcid | Readout channel ID | N/A | instr.det |
| rfid | Rfid | Reference image ID | N/A | meta.id |
| sciinpseeing | Sciinpseeing | Science image seeing | arcsec | instr.obsty.seeing |
| scibckgnd | Scibckgnd | Science image background | N/A | instr.skyLevel |
| scisigpix | Scisigpix | Science image sigma per pixel | N/A | stat.stdev;instr.pixel |
| magzpsci | Magzpsci | Magnitude zero point | mag | phot.calib |
| magzpsciunc | Magzpsciunc | Magnitude zero point uncertainty | mag | stat.error;phot.calib |
| magzpscirms | Magzpscirms | Magnitude zero point RMS | mag | stat.stdev;phot.calib |
| clrcoeff | Clrcoeff | Color coefficient | N/A | arith.factor |
| clrcounc | Clrcounc | Color coefficient uncertainty | N/A | stat.error;arith.factor |
| exptime | Exptime | Exposure time | s | time.duration;obs.exposure |
| adpctdif1 | Adpctdif1 | Adaptive percentile difference 1 | N/A | stat.value |
| adpctdif2 | Adpctdif2 | Adaptive percentile difference 2 | N/A | stat.value |
| diffmaglim | Diffmaglim | Difference image magnitude limit | mag | phot.mag;stat.min |
| programid | Programid | Program ID | N/A | obs.program |
| procstatus | Procstatus | Processing status | N/A | meta.code.status |
| distnr | Distnr | Distance to nearest source | arcsec | pos.angDistance |
| ranr | Ranr | RA of nearest source | deg | pos.eq.ra |
| decnr | Decnr | Dec of nearest source | deg | pos.eq.dec |
| magnr | Magnr | Magnitude of nearest source | mag | phot.mag |
| sigmagnr | Sigmagnr | Magnitude error of nearest source | mag | stat.error;phot.mag |
| chinr | Chinr | Chi of nearest source | N/A | stat.fit.chi2 |
| sharpnr | Sharpnr | Sharpness of nearest source | N/A | stat.value |
| created_date | Created_date | Date record was created | N/A | time.creation |
Columns that are parts of indices are marked like this.
VO nerds may sometimes need VOResource XML for this table.