Looking at the night sky in the cold temperatures, you might be wondering what the coldest place in the universe is. You might guess that it would be in an intergalactic space away from any star or planet.
The temperature in space furthest from all sources of heat, such as stars, galaxies, and gas clouds may be as low as 2.725K. The only thing that would raise the temperature in such space is the residual heat from the Big Bang, known as the cosmic microwave background.
However, there is an even colder place in the universe that scientists have discovered. In this blog article, we’ll discuss the coldest place in the universe, how it was found, and why it’s so chilly.
The Boomerang Nebula
The Boomerang Nebula is the coldest place in the universe that has been found so far. It’s a protoplanetary or preplanetary nebula, which is a short-lived phase before it turns into a planetary nebula. This is when the star has shed its outer layers but the temperature has not begun to heat up.
The central star of the Boomerang Nebula is a dying red giant star in the constellation Centaurus. It is located about 5000 lightyears outside of our solar system.
This star at its center is losing its outer layers quicker than other stars. As a result, It is the only preplanetary nebula that expels gas at a speed ten times faster than a comparable nebula.
How Boomerang Nebula Was Discovered
The Boomerang Nebula was first observed by astronomers Keith Taylor and Mike Scarrott at Siding Spring Observatory in Australia in 1980. To the Australian astronomers, the shape of the nebula resembled a boomerang shape, hence the name Boomerang Nebula.
In 1990, astronomer Raghvendra Sahai pointed out that the star’s wind might expand fast as it streamed out, lowering the temperature drastically and turning it into a cosmic refrigerator.The Boomerang Nebula was therefore studied in 1995 by a team under Sahai utilizing the Swedish-ESO Submillimetre Telescope in Chile.
In 1998, however, the Hubble Space Telescope would reveal a shape of the Boomerang Nebula that looked more like a bow-tie shape or an hourglass.
Sahai’s team found that this coldest known place in the universe had a temperature of about -272.15°C, which is only 1 degree above absolute zero! The researchers used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to verify the temperature of the Boomerang Nebula in 2013.
Why Is It So Cold There?
The Boomerang Nebula is so cold because when the dying red giant star sheds its outer layers, the ejecta emerges in the form of two jets into interstellar space. The fast-moving ejecta moves through a relatively tiny opening then undergoes rapid expansion and cools down. It is so cold that it’s even lower than the temperature of the cosmic microwave background, the big bang’s afterglow.
This is the coldest natural place in the known Universe, with some parts of the nebula reaching even colder temperatures as low as 0.5 Kevin!
Scientists are able to produce cold temperatures in the lab on Earth. The lowest temperature record was 38 trillionths of a degree warmer than absolute zero for a few seconds, which is even colder than the Boomerang Nebula’s low temperatures.
Closing Thoughts on the Coldest Place in the Universe
The Boomerang Nebula is the coldest place in the universe that scientists have discovered. It has a temperature of about -272.15°C, which is only 1 degree above absolute zero! This makes it even colder than the outer space remote from stars and planets, with just the cosmic microwave background radiation from the big bang as a source of warmth.