82 G. Eridani

Although Geneva won't tell Anglophones, 82 Gould Eridani is open access. This system, also Henry Draper's 20794 or Gliese 139, owns at least two planets. The inner one b was constrained, sort-of; so was a 90-ish-day one, once-upon-a-time "d". The forty-day one between, then "c", was sus, and ruled out a couple years back. NASA still haven't updated c which they still think is "d".

After decades of watching, Nari et al. have a new "d" (I'm tweaking the format):

We confirm the presence of three planets, with periods of 18.3142 ±0.0022 days, 89.68 ±0.10 d, and 647.6_−2.7^+2.5 d; along with [minimum-]masses of 2.15 ±0.17 M_⊕, 2.98 ±0.29 M_⊕, and 5.82 ±0.57 M_⊕ respectively. For the outer planet, we find an eccentricity of 0.45_−0.11^+0.10, whereas the inner planets are compatible with circular orbits. The latter is likely to be a rocky planet in the habitable zone of HD 20794. From the analysis of activity indicators, we find evidence of a magnetic cycle with a period of ~3000 d, along with evidence pointing to a rotation period of ~39 d.

The rotation is what raised up that forty day phantom.

The system is only 19.7 light years away, 6.04 parsecs. Its star is 68.7% luminosity, ~79% solar mass. It is too heavy for us to use the photoeccentric-effect on its planets. Eccentricities, rather, are measured direct - where they could be; the inner planets are e<0.15ish. The planets were verified with a post-processing pipeline ... tool called YARARA.

This 2014 paper is how they got HZ. As to "d":

The stellar flux at the periastron [0.75 AU] is almost seven times stronger than the stellar flux at the apoaster [1.96 AU]. HD 20794 d spends ~59% of its orbit inside the optimistic HZ, and ~38% of its orbit inside the conservative HZ.

I am not an optimist; "d" is mostly too cold. Its extreme eccentricity crossing the HZ suggests it also loses air, as well as running off any other HZ planets. 'Tis hardly a laboratoire pour la quête de la vie.

82 G.E. might rather serve as a lab for planetology and orbital-dynamics. Its star is a quiet one by G standards so might actually not be hitting the planets too hard; and "d" is heavy. I assume this planet a Sudarsky II subUranus and not hycean. Nari's paper likens it to Gliese 514 b around a M at 7.6 pc.

Planet "d" should be directly visible to Habitable World Observatory, they say. Giving us inclination, radius, albedo; therefore density.

To me, that "d" eccentricity signals some "e" they haven't seen yet. They allow a 50 M_⊕ halfSaturn could run out at 3-10 AU. This may be visible to space 'scopes also. That's the sort of thing that could Zeipel us some transits someday.