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gaia data release 3 documentation

20.13 Variability tables

20.13.14 vari_planetary_transit

This table describes the Planetary Transit candidate events.

Columns description:

solution_id : Solution Identifier (long)

All Gaia data processed by the Data Processing and Analysis Consortium comes tagged with a solution identifier. This is a numeric field attached to each table row that can be used to unequivocally identify the version of all the subsystems that were used in the generation of the data as well as the input data used. It is mainly for internal DPAC use but is included in the published data releases to enable end users to examine the provenance of processed data products. To decode a given solution ID visit

source_id : Unique source identifier (long)

A unique single numerical identifier of the source obtained from gaia_source (for a detailed description see gaia_source.source_id).

transit_reference_time : Mid-transit reference time (double, Time[Barycentric JD in TCB - 2 455 197.5 (day)])

A representative time of a planetary mid-transit during the Gaia mission, used as the reference epoch. Usually it will be chosen to be a time close to the mean of all Gaia observing epochs used in the analysis, in order to reduce its error.

An observation time t is considered to occur within a transit if:


where T0 stands for transit_reference_time, P for transit_period, and w for transit_duration.

transit_period : Most probable transit period (double, Time[day])

We restrict ourselves to strictly periodic planetary transits, otherwise we cannot identify them. This is the most probable period we found.

transit_depth : Transit depth (float, Magnitude[mmag])

Transit depth is the amount by which the observed star brightness dims when the planet transits between the Solar System and the star. Physically it may hint to the size of the planet.

transit_duration : Transit duration (float, Time[day])

Transit duration is the length of time the transit lasts. The low cadence of Gaia photometry does not allow a detailed transit model with ingress and egress, so our assumption is that the transit has a simple box-like shape, and so the duration is well defined. Physically it is mainly related to the stellar radius and the orbital inclination.

num_in_transit : Number of in-transit observations (byte)

Number of Gaia photometric observations that occurred during planetary transits. Only above a certain number we consider this a detection.