NASA has released a high-resolution photo taken by the NASA/ESA Hubble Space Telescope of an emission nebula called N44.
This Hubble image shows N44, an emission nebula located 170,000 light-years away in the southern constellation of Dorado. Image credit: NASA / ESA / Hubble / Ksoll et al. / Gladys Kober, NASA & Catholic University of America.
The object spans about 1,000 light-years and is about 170,000 light-years away from Earth.
N44 is classified as an emission nebula, which means its gas has been ionized by the radiation of nearby stars.
As this gas begins to cool from its higher-energy state to a lower-energy state, it emits energy in the form of light, causing the nebula to glow.
“N44 is a complex nebula filled with glowing hydrogen gas, dark lanes of dust, massive stars, and many populations of stars of different ages,” Hubble astronomers said.
“One of its most distinctive features, however, is the dark, starry gap called a ‘superbubble,’ visible in the new image in the upper central region.”
“The hole is about 250 light-years wide and its presence is still something of a mystery,” they added.
“Stellar winds expelled by massive stars in the bubble’s interior may have driven away the gas, but this is inconsistent with measured wind velocities in the bubble.”
“Another possibility, since N44 is filled with massive stars that would expire in titanic explosions, is that the expanding shells of old supernovae sculpted the cosmic cavern.”
Astronomers previously spotted a supernova remnant in the vicinity of N44’s superbubble.
They also identified a 5 million year difference in age between stars within and at the rim of the superbubble, indicating multiple, chain-reaction star-forming events.
“The deep blue area at about 5 o’clock around the superbubble is one of the hottest regions of the nebula and the area of the most intense star formation,” the researchers said.