How quickly could a rogue Earth return to habitability after a deep freeze?

Background
A large star makes a relatively close approach to a solar system like our own and the orbits of many of the planets are badly perturbed. A planet similar to Earth is in the wrong place at the wrong time and receives a particularly strong gravitational pull from the passing star that flings the planet out into interstellar space. Millions of years pass and by a strange coincidence this rogue planet blunders into another very similar solar system and is captured into an orbit that approximates to that from where it came from (strange but true for the purposes of this question).

Human explorers arrive in this new solar system shortly after the rogue Earth arrives. This rogue Earth is now starting to thaw but has not yet reached a stable thermal equilibrium as the process will take some time.

Question
How long after the capture of the rogue Earth before the human explorers can safely land on the planet, establish a base making use of local resources and how long before they can go outside without protective clothing?

Assume Current technology level plus what might reasonably be foreseen within the next few hundred years (quite a lot of scope).

posted over 4 years ago

Slarty‭

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