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gaia data release 3 documentation

20.13 Variability tables

20.13.17 vari_short_timescale

This table describes the short-timescale sources.

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 https://gaia.esac.esa.int/decoder/solnDecoder.jsp

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).

amplitude_estimate : Amplitude estimate of all per-CCD G-band photometry (95th quantile - 5th quantile) (float, Magnitude[mag])

This parameter is filled with the amplitude estimate from per-CCD G-band photometry. This amplitude estimate is calculated as the quantile difference (95th quantile - 5th quantile) of all per-CCD G-band measurements.

number_of_fov_transits : Number of FoV transits with more than 7 CCD measurements after time series cleaning (short)

Number of FoV transits that have more than 7 CCD measurements after time series cleaning (i.e., not necessarily from all the FoV transits available for the source).

mean_of_fov_abbe_values : Mean of per-FoV Abbe values derived from per-CCD G-band photometry (float)

This parameter represents the mean of per-FoV Abbe values derived from per-CCD G-band photometry. Considering a given source, for each of its FoV transits containing more than one per-CCD measurement, the associated Abbe value from per-CCD G-band photometry is derived as

Abbe=i=1n-1(yi+1-yi)22i=1n(yi-y¯)2, (20.61)

where {ti,yi} is a time-sorted time series per FoV of size n, such that ti<ti+1 for all i<n, and y¯ is the mean of the per-CCD measurements of the transit. The value of mean_of_fov_abbe_values is calculated as the mean of these per-FoV Abbe values.

variogram_num_points : Number of selected timescale(s) derived from the variogram (byte)

This parameter represents the number of selected timescale(s) derived from the variogram. For DR3, it is only 1.

variogram_char_timescales : Characteristic timescale(s) of variability (float[variogram_num_points] array, Time[day])

This parameter represents the variogram characteristic timescale(s) derived from the variogram analysis of the source, if it has been flagged as a short timescale variable candidate.

variogram_values : Variogram values associated with the variogram_char_timescales (double[variogram_num_points] array, Misc[mag2])

This parameter represents the variogram value(s) associated with the variogram characteristic timescales variogram_char_timescales.

frequency : Frequency search result for either G CCD, G FoV, BP or RP photometry (double, Frequency[day-1])

The parameter represents the frequency value resulting from the period search (method LEAST_SQUARE in DR3) performed either on the per-CCD G-band photometry, per-FoV G-band photometry, GBP photometry or GRP photometry. For DR3, only per-CCD G-band photometry is used to compute the frequency. It is set to NULL if the number of CCD measurements is less than 180.