![]() Once astronomers and astrophysicists had a better understanding of fusion, they were able to come up with more complete models, coupled with emission data observed from several stars, for the lives of stars. "Before the 1930s, one of the main ideas of how stars worked was that energy was coming just from gravitational energy." "A lot of the science is relatively new, like in the last century, because an integral part of understanding how a star works comes from understanding nuclear reactions and fusion," said Testa, who researches the heating mechanisms and processes of X-ray emissions, such as solar flares, in the outer layers of the sun's atmosphere. Can black holes transport you to other worlds? What does the edge of the solar system look like? To arrive at this timeline for both the sun and all stars of its relative mass, scientists needed to know how it emitted energy, which was difficult before nuclear fusion in solar masses could be taken into account. From there, what remains of the sun will spend trillions of years cooling off before ultimately becoming a non-emitting object. The nebula will be visible for only about 10,000 years, Testa said - the blink of an eye in cosmic time. ![]() The sun will then begin fusing the helium left over from hydrogen fusion into carbon and oxygen, before ultimately collapsing down to its core, leaving behind a gorgeous planetary nebula - a glowing shell of hot, leftover plasma - in its outer layers as it shrinks to an incredibly dense, significantly hotter, Earth-size stellar corpse known as a white dwarf. Within a few million years of this initial expansion, it's likely that the sun will also consume the rocky remains of the Earth, according to a 2008 study published in the Monthly Notices of the Royal Astronomical Society (opens in new tab). Of course, this will almost certainly be bad news for whatever life remains on our planet by that point - assuming any has survived the 10% increase in the sun's brightness that is expected to vaporize Earth's oceans in 1 billion to 1.5 billion years, according to a 2014 study published in Geophysical Research Letters (opens in new tab). This expansion will gradually swallow the sun's neighboring planets, Mercury and Venus, and ratchet up the sun's solar winds to the point that they quash Earth's magnetic field and strip off its atmosphere. Meanwhile, the outer part of the sun, which will still contain hydrogen, will expand, glowing red as it cools. At this point roughly 5 billion years in the future, the sun will stop generating heat via nuclear fusion, and its core will become unstable and contract, according to NASA (opens in new tab). After the sun has burned through most of the hydrogen in its core, it will transition to its next phase as a red giant.
0 Comments
Leave a Reply. |