This diagram depicts the orbits of the planets orbiting the star Tau Ceti. Orbital parameters are taken from:
Tuomi et al. (2012) "Signals embedded in the radial velocity noise. Periodic variations in the tau Ceti velocities"
https://arxiv.org/abs/1212.4277
Planets e and f which are only detected in the combined datasets are shown with dotted orbits to indicate their less-certain status. For orbital positions the mean anomalies were computed from the time of periastron values given in table 9 of that paper. The symbols for the star and the planets are not drawn to scale.
The habitable zone is plotted according to the formulae given in:
Underwood, Jones and Sleep (2003) "The evolution of habitable zones during stellar lifetimes and its implications on the search for extraterrestrial life"
https://arxiv.org/abs/astro-ph/0312522

Red = Recent Venus (inner) – Runaway greenhouse (outer)
Yellow = Runaway greenhouse (inner) – Water loss (outer)
Green = Water loss (inner) – First CO2 condensation (outer) = most conservative habitable zone
Cyan = First CO2 condensation (inner) – Maximum greenhouse (outer)
Blue = Maximum greenhouse (inner) – Early Mars (outer)
The debris disc is too large to be shown on this scale.
Own work
Icalanise