The Boomerang nebula
The Boomerang nebula, also called the bowtie nebula since the Hubble space telescope revealed more detail, located 5,000 light-years from Earth,in the constellation Centaurus, is at 1 kelvin the coldest place known outside a laboratory.
It is formed from the outflow of gas from a star at its core. The gas is moving outwards at a speed of about 600,000 km/h and expanding rapidly as it moves out into space. This expansion is the cause of the nebula's very low temperature.