A Word of Caution About Exoplanet Archival Data

In addition to original results from observations, exoplanet archives such as exoplanets.org and exoplanet.eu contain auxiliary products (unpublished semimajor axes and/or stellar parameters taken from supplementary studies) that are not sufficiently documented and/or not up-to-date, even for famous extrasolar systems. The NASA Exoplanet Archive does not publish auxiliary products, but a number of its entries are outdated; researchers should be encouraged to submit their results upon publication. In this note, we describe our recent experience with auxiliary products in three such systems, Kepler-223, Kepler-11, and GJ 876. We summarize the (in)compatible dynamical data that we obtained so that others may not have to go through the same trouble, even if this means relying on the original publications and private communications with the authors. At the same time, large statistical surveys utilizing only archival data are bound to be inaccurate to a certain extent.