The HWC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo.
Surface planetary habitability is thought to require an orbit at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment.
Some exoplanet candidates detected by radial velocity that were originally thought to be potentially habitable were later found to most likely be artifacts of stellar activity.
However based on the later measurement of host star parallax by Gaia, the radius of the planet was revised upward to 3.226+0.201−0.315 R🜨, resulting in it being a ice giant like Neptune with poor prospect for habitability.
[88][89] KOI-1686.01 was also considered a potentially habitable exoplanet after its detection in 2011, until proven a false positive by NASA in 2015.