We estimate the distance from the Sun to sources in Gaia eDR3 that have parallaxes. We provide two types of distance estimate, together with their corresponding asymmetric uncertainties, using Bayesian posterior density functions that we sample for each source. Our prior is based on a detailed model of the 3D spatial, colour, and magnitude distribution of stars in our Galaxy that includes a 3D map of interstellar extinction.
The first type of distance estimate is purely geometric, in that it only makes use of the Gaia parallax and parallax uncertainty. This uses a direction-dependent distance prior derived from our Galaxy model. The second type of distance estimate is photogeometric: in addition to parallax it also uses the source's G-band magnitude and BP-RP colour. This type of estimate uses the geometric prior together with a direction-dependent and colour-dependent prior on the absolute magnitude of the star.
Our distance estimate and uncertainties are quantiles, so are invariant under logarithmic transformations. This means that our median estimate of the distance can be used to give the median estimate of the distance modulus, and likewise for the uncertainties.
For applications that cannot be satisfied through TAP, you can download a full table dump.
This table joins the DR3 "lite" table (consisting only of the columns necessary for the most basic science) with the estimated geometric and photogeometric distances. Note that this is an inner join, i.e., DR3 objects without distance estimates will not show up here.
Note: Due to current limitations of the postgres query planner, this table cannot usefully be used in positional joins ("crossmatches"). See the Tricking the query planner example.