ASTRONOMERS DISCOVER HOW PLANETARY NEBULAE FORM MESMERIZING SHAPES
The study sheds light on what the Sun will look like when it dies.
WHEN A STAR RUNS OUT OF FUEL,
it sheds its outer layers of gas and, if it doesn't explode in a supernova, forms a glowing shell of ionized gas that expands into space.
Shells like these are known as planetary nebulae, and they make for some of the most colorful, mesmerizing images we see of the cosmos. As beautiful as they are, planetary nebulae are also longstanding astronomical mysteries. Until recently, scientists did not know the reason behind their odd shapes. However, a team of astronomers may have just solved this artful mystery after extensively observing the stellar winds that form around aging stars. Their findings are detailed in a study published Thursday in the journal Science and give scientists a unique look at what the shape of our Sun might become.
A COLORFUL LOOK INTO THE SUN'S FUTURE —
The Sun will run out of fuel in about 5 billion years, becoming a red giant star, or a bright star of low mass that is near the end of its life. The dying star will eventually form a planetary nebula around it, heating up while its radiation causes the expanding ejected layers of material to glow. The planetary nebulae produced by stars are almost never round, instead, producing a variety of colorful shapes. "The Sun - which will ultimately become a red giant - is as round as a billiard ball, so we wondered: How can such a star produce all these different shapes?" lead author Leen Decin, a researcher at the KU Leuven Institute of Astronomy, explains. Using the ALMA Observatory in Chile, Decin and her team examined the stellar winds that carry particles ejected aging stars. The team gathered the most detailed collection of observations of these stellar winds yet, each of them made using the exact same method in order to be able to directly compare them.
