Acart

Three different sources mention a planet called Acart (which sometimes is spelled Akart).

Astronomical data

LOCATION: Acart is supposedly only 5 Light Years away from Earth. More information is lacking.
At present, only the 3 stars of Alpha Centauri are known to be within that range. Barnard's star is at 5.9 light years.

Civilization

Appearance: standard human looking (Phenotype A1), meaning indistinguishable from Earth humans.
"one could say much like us, only more pallid. All I saw had hair color of straw, but a few had dark hair. Median stature greater than ours."

Culture: "They talked in a German tongue, but could speak many tongues of earth, and had learned it as many similar races have that observes us, and can be here undetected."

Until fairly recently Acart would have faced an overpopulation problem, but then a large part of the population was wiped out. Sources contradict each other with regard to the current population, which would be either 23 billion or 1.26 billion.

Case Information

Arthur Berlet was taken, against his will, for 9 days to Acart. Mario Restier was taken for 3 months.

Source & Reliability

Berlet and Restier are experiencers, i.e. first-hand witnesses. The Arthur Berlet case was investigated by 3 different investigators who all came to the conclusion that he was truthful.