Table information for 'alerce_tap.ztf_object'

General

Table Description:

ZTF-specific properties for astronomical objects including color indices, stellar classification, photometric correction flags, and historical detection statistics from the Zwicky Transient Facility survey.

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'

Citing this table

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:alerce_tap_ztf_o,
  year=2026,
  title={{ZTF} Object Properties},
  author={{ALeRCE} Team},
  url={http://tap.alerce.online/tableinfo/alerce_tap.ztf_object},
  howpublished={{VO} resource provided by the {ALeRCE} {TAP} service}
}

Columns

Sorted by DB column index. [Sort alphabetically]

NameTable Head DescriptionUnitUCD
oid Oid Unique identifier for this object N/A meta.id;src
g_r_max G_r_max Maximum g-r color (difference between minimum g and r band magnitudes) N/A phot.color;stat.max
g_r_max_corr G_r_max_corr Maximum g-r color using corrected magnitudes N/A phot.color;stat.max;arith.corrected
g_r_mean G_r_mean Mean g-r color (difference between mean g and r band magnitudes) N/A phot.color;stat.mean
g_r_mean_corr G_r_mean_corr Mean g-r color using corrected magnitudes N/A phot.color;stat.mean;arith.corrected
corrected Corrected Whether the corrected light curve was computed and can be used N/A N/A
stellar Stellar Whether the object is likely a stellar-like (unresolved) source based on PS1 and ZTF reference image properties N/A N/A
reference_change Reference_change Reference image change flag indicating template update N/A N/A
diffpos Diffpos Difference image positivity flag N/A N/A
ndethist Ndethist Number of spatially-coincident detections within 1.5 arcsec going back to beginning of survey; only detections on the same field and readout-channel ID are counted, down to S/N ~ 3 N/A N/A
ncovhist Ncovhist Number of times the object position fell on any field and readout-channel going back to beginning of survey N/A N/A
mjdstarthist Mjdstarthist Earliest Modified Julian Date corresponding to ndethist d time.start
mjdendhist Mjdendhist Latest Modified Julian Date corresponding to ndethist d time.end
created_date Created_date Date record was created N/A time.creation

Columns that are parts of indices are marked like this.

VOResource

VO nerds may sometimes need VOResource XML for this table.