# 14.3.8 vari_short_timescale

This table describes the short-timescale sources. For DR2, all sources in this table were selected according to their variogram analysis.

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 where 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 (quantile(95%)-quantile(5%)) (double, Magnitude[mag])

This parameter is filled with the amplitude estimate from per-CCD G-band photometry. This amplitude estimate is calculated as the quantile differ- ence (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 (int, Dimensionless[see description])

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

mean_of_fov_abbe_values : Mean of per-FOV Abbe values derived from CCD G-band photometry (double, Dimensionless[see description])

This parameter is filled by 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 $abbe=\frac{\sum(mag(t_{i+1})-mag(t_{i}))^{2}}{2\sum(mag(t_{i})-)^{% 2}}$ where $$ 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 points in the variogram (int, Dimensionless[see description])

This parameter is filled by the number of characteristic points in the variogram and associated time scales. For DR2, it is only 1.

variogram_char_timescales : Characteristic time scales of variability (double, Time[day])

This parameter is filled by 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, Misc[mag**2])

This parameter is filled by 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 (Null if no periodicity detected) (double, Frequency[$day^{-1}$])

The parameter is filled by the frequency value resulting from the period search (method LOMB_SCARGLE for DR2) performed either on the per-CCD G-band photometry, per-FoV G-band photometry, BP photometry or RP photometry, if periodicity has been detected. Otherwise it is set to NULL.