This beautiful and distinctive object captured by the Hubble Space Telescope is a planetary nebula called NGC 2371/2, located in the constellation of Gemini (The Twins). It has an unusual name because of its unusual shape — when astronomers first studied the nebula, they thought it was two different structures, so it was named NGC 2371 and NGC 2372.
However, the object is actually a singular nebula with two separate lobes. As we discussed last week, despite its name a planetary nebula actually has nothing to do with planets. Instead, it is a bubble of gas which is pushed out into space by a dying star.
In the case of NGC 2371/2, it was formed when a star similar to our sun reached the end of its life. In its final phases of life as a red giant, it threw off its outer layers of gas. The gas was pushed outward while the material within the bubble was consumed, leaving just a gas shell around the star remnant. The remnant can be seen right in the middle of the image: the glowing star between the two lobes. That remnant is still extremely hot, at a mind-bending 240,000 degrees Fahrenheit (134,000 degrees Celsius).
The rest of the planetary nebula structure is complex, according to Hubble scientists. It is “filled with dense knots of gas, fast-moving jets that appear to be changing direction over time, and expanding clouds of material streaming outwards on diametrically opposite sides of the remnant star.”
Parts of the structure are illuminated by the radiation given off by the star remnant. Because it is so hot, the remnant pumps out ultraviolet light which ionizes the gases in the shell and makes them glow, creating the distinctive patterns and colors.
The complex structure won’t last forever, though. Over the next few thousand years, the remnant will gradually cool, losing heat until it becomes a white dwarf. As this happens the lobes will stop shining and will gradually dissipate into the blackness of space.
