The sun will die in the radiance of beauty.
We may not know exactly what this death will look like billions of years in the future, but the death of other stars like the Sun gives us an idea of how this spectacular process might unfold.
One of these objects has become the subject of a new image taken by the Hubble Space Telescope. Its name is NGC 2438, it is located about 1370 light years from us, and it is the so-called planetary nebula.
Planetary nebulae have nothing to do with planets; they are so named because in the first telescopes they looked like planets. This is because they are roughly spherical – huge clouds of gas ejected from a dying sun-like star.
As the Sun approaches the end of its life cycle, it runs out of hydrogen to melt in the core, the core begins to cool and contract, upsetting the delicate balance between the internal pressure of gravity and the external thermal and radiation pressures created by nuclear fusion. …
This will bring in additional hydrogen from the area around the core, which will ignite in the shell around the core. This will create a large amount of energy, causing the outer layers of the Sun to turn into a huge, bright object that can reach the orbit of Mars.
Eventually, its instability will trigger a series of eruptions that will throw most of its mass into the space around it. The core of the star will collapse into a white dwarf, shining brightly with residual heat and illuminating the ejected material from the inside.
It is the planetary nebula that now hosts NGC 2438. It is a very short stage in a star’s life, lasting only about 10,000 years; The ejected material continues to expand into space and eventually becomes too thin to be seen. Each pixel is color-coded: blue represents oxygen, green represents hydrogen, orange represents nitrogen, and red represents sulfur.
NGC 2438 is also interesting due to the luminous “halo” surrounding the inner ring of the nebula, which is seen in many circular planetary nebulae (but not in the new Hubble image). The study, which included NGC 2438, showed that the halo is excited by ionizing radiation from the star itself, which causes the gas to glow.
The material surrounding NGC 2438 is expanding at about 37 kilometers (23 miles) per second. In a few thousand years, give or take, it will become too thin to be seen. Meanwhile, there is still a lot of time left before the Sun; its transformation into a red giant will begin in about 5 billion years.
If any people do see it, they will do it from what we hope is a very safe distance.