NASA’s Hubble Space Telescope has revealed an impressive image of planetary nebula Kohoutek 4-55, located 4,600 light-years away in the Cygnus constellation. The nebula represents the last stage of a giant star’s life, offering a glimpse into the processes occurring as stars reach their end.
Kohoutek 4-55 features a multi-layered structure, with a faint gas layer surrounding a bright inner ring. A broad halo of ionised nitrogen encircles the nebula, with different colours representing various elements. The image shows nitrogen in red and orange, hydrogen in green, and oxygen in blue.
At the heart of this nebula is the remnants of a red giant star that has exhausted its fuel. As it sheds its outer layers, the star's core becomes extremely hot and radiates ultraviolet light, ionising atoms in the surrounding gas, which then causes the nebula to glow.
This display of energy and colour is only temporary. The star’s final phase of fusion will last just tens of thousands of years, after which the star will cool down into a white dwarf, no longer illuminating the surrounding gas.
This image marks the final work of Hubble's Wide Field and Planetary Camera 2 (WFPC2), an instrument that had been part of the telescope since 1993. It was responsible for many iconic images before it was replaced by the Wide Field Camera 3 in 2009 during a servicing mission.
In the last few days before the WFPC2 was removed, it captured the data used in this final image of Kohoutek 4-55. This image represents a send-off for an instrument that contributed significantly to Hubble's most celebrated discoveries over its 16-year lifespan.
The new image showcases advanced processing techniques that highlight the intricate details of the nebula, further cementing Hubble’s legacy in the study of space. The telescope continues to provide valuable insights into stellar evolution, planetary formation, and the life cycles of stars.