The Boomerang Nebula is three times colder than Antarctica, and colder than space itself

The Boomerang Nebula is the coldest known naturally occurring object in the universe at about minus 272 degrees Celsius, over three times colder than Antarctica and colder than the cosmic microwave background.

Its extreme cold was first identified by astronomers Raghvendra Sahai and Lars Åke Nyman in 1997 using the Swedish ESO Submillimetre Telescope in Chile.

The nebula formed from a dying red giant star expelling gas at extremely high speeds, possibly triggered by a companion star plunging into it, as observed by the Atacama Large Millimeter/submillimeter Array (ALMA).

Rapid expansion of gas causes the intense cold because thermal energy is stripped away faster than in a typical dying star, allowing the outflow to drop below the background temperature of space.

Named for its bowtie shape seen by the Hubble Space Telescope, ALMA revealed a central hourglass structure surrounded by patchy ultra-cold outflowing gas.