Kapteyn b
Distance: 12.8 Lightyears
Star: Kapteyn
Constellation: Pictor
Kapteyn b is one of the closest potentially habitable planets at just 12.8 lightyears away. This has made many scientists push for more study in the world. This is considered a Super-Earth due to being much larger than Earth in radius and mass. Yet it is not as large as Uranus or Neptune. One big drawback is likely the estimated surface temperature, which averages -91 degrees Fahrenheit.
All signs point to it being a rocky planet like Earth, however. Its host star, Kapteyn, is 11 billion years old. Much older than our Sun (4.6 billion years old). The surface temperature is 3550 K here whereas our Sun sits at a solid 5778 K. This Red Subdwarf star has more than 25% more mass than our Sun, giving it the ability to last 100 to 200 billion years. Roughly 10 to 20 times longer than our Sun. Due to the temperature on the surface, however, it would be hard to reach normal liquid water. Yet it is assumed that if proper greenhouse gases were introduced, the temperature might rise. Proper Carbon Dioxide is already present! That could result in Kapteyn b becoming a planet that could house human life. Yet it would take quite a while for greenhouse gases to truly warm it up significantly.