The Boomerang Nebula Is The Coldest Place In The Known Universe
You might imagine that the coldest place in the universe would be deep in the recesses of space, far away from the warming rays of a star. On the contrary, it turns out that the coldest place in the universe is directly surrounding a star, albeit a dying one. The Boomerang Nebula is a cloud of gas that's being shed by a small dying star on its way to becoming a red giant. The nebula is expanding at an incredible rate, expelling gas at about 102 miles (164 km) per second. That's why it's so cold: as gas expands, its temperature drops. So why is the nebula shaped like a boomerang? It's not, actually. The first astronomers to spot it with a ground-based telescope in 1980 noticed it had a lopsided shape, and perhaps because they were Australian, a boomerang was the first thing that came to mind. Later, in the late 1990s, researchers took a higher-resolution glance with the Hubble Space Telescope and saw that it actually had a double-lobe structure, kind of like a bow-tie. Finally, in 2013, astronomers took an even closer look and found that it's just a round cloud of gas. A ring of dust had been blocking some of its light, making it look like a bow-tie.
from SciShow Space
Key Facts In This Video
The Boomerang Nebula is a pre-planetary nebula: or a low-mass star that's near the end of its life. (0:52)
The Boomerang Nebula is -458ºF (272ºC), or 1 Kelvin -- just above absolute zero. (1:45)
The nebula isn't shaped like a boomerang. Astronomers once thought it was shaped like a bow-tie, but it turned out to be round -- a ring of dust was blocking some of the light. (2:42)