Scientists engaged in learning on the gas clouds
In a new image from the Hubble Space Telescope, NGC 6891 glows brightly, as the observatory aids scientists in understanding more about how these gas clouds began and evolved.
NGC 6891 is referred to as a “planetary nebula” by astronomers, a phrase derived from a previous misidentification with planets when telescope technology was still in its infancy. We now know that such nebulas occur as a result of supernova explosions, in which massive stars shed their gas. The star’s white dwarf remnant remains behind, steadily cooling.
The Hubble Space Telescope captured high-resolution photos of knots and filaments coiled around the white dwarf deep within the cloud. The data also suggests that the nebula’s outer halo of gas is expanding faster than the nebula’s innermost component, and the measurements even catch gas shells orientated in various directions.
Based on their movements, astronomers estimate that one of the shells is 4,800 years old and the outer halo is 28,000 years old. It denotes a sequence of separate eruptions from the dying star at various times “In a statement, NASA officials said.
Findings and study to date
The glow from NGC 6891 is caused by the white dwarf stars ionizing or stripping electrons from the hydrogen gas around them.
“The charged electrons release energy as they revert from their higher-energy state to a lower-energy state by recombining with hydrogen nuclei. They emit energy in the form of light, which causes the gas in the nebula to shine “According to NASA.
Hubble is still recovering from a synchronization problem that occurred on October 23. Its instruments are gradually being reintroduced to the public. Hubble was last maintained in person in 2009, and astronauts are no longer able to reach it due to the retirement of the space shuttle. However, the 31-year-old telescope has a lot of outdated data to sort through.