It’s famous that the universe is changeable: even the stars that become visible static and predictable every night are subject matter to change. This figure from the NASA Hubble Space Telescope shows planetary nebula Hen 3-1333. Planetary nebulae have not anything to do with planets — they truly represent the death throes of mid-sized stars like the sun. As they current out their outer layers, large, irregular globes of glowing gas develop around them, which appeared planet-like throughout the small telescopes that were used by their first explorers.
The star at the heart of Hen 3-1333 is idea to have a mass of around 60% that of the sun, but not like the sun, its visible brightness varies significantly over time. Astronomers trust this variability is caused by a disc of dust which lies almost edge-on when vision from Earth, which occasionally obscures the star.
It is a Wolf–Rayet-type star — a late stage in the growth of sun-sized stars. These are named after (and share many observational personality with) Wolf–Rayet stars, which are a lot larger. Why the comparison? Both Wolf–Rayet and Wolf–Rayet type stars are hot and bright as their helium cores are showing: the former because of the strong stellar winds feature of these stars; the latter because the outer layers of the stars have been puffed left as the star runs low on fuel.
The showing helium core, rich with heavier elements, means that the exteriors of these stars are far hotter than the sun, typically 25,000 to 50,000 degrees Celsius (45,030 to 90,030 Fahrenheit). The sun has a moderately chilly surface temperature of just 5,500 degrees Celsius (9,932 Fahrenheit).
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