Reviewed by Lexie CornerDec 9 2024
A new image released by NSF NOIRLab shows the spiral arms of Messier 83, revealing areas of star formation.
Twelve million light-years away lies the galactic masterpiece Messier 83, also known as the Southern Pinwheel Galaxy. Its swirling spiral arms display a high rate of star formation and have been host to six observed supernovae. This image was captured with the Department of Energy-fabricated Dark Energy Camera, mounted on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF NOIRLab. Image Credit: NOIRLab
Messier 83, often called the Southern Pinwheel Galaxy, is one of the most prominent spiral galaxies visible in the night sky. It gets its name from its resemblance to the Pinwheel Galaxy and spans about 50,000 light-years, making it smaller than the Milky Way. Despite its size, Messier 83 has a faster rate of star formation, as evidenced by the pink bursts of activity along its spiral arms. This intense starburst is likely the result of a past merger with another galaxy.
The image was captured using the Dark Energy Camera (DECam), a Department of Energy instrument mounted on the US National Science Foundation’s Víctor M. Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO), part of NSF NOIRLab.
Between 1750 and 1754, French astronomer Nicolas-Louis de Lacaille studied the night sky to measure distances between planets. During this period, he cataloged 10,000 stars and identified 42 nebulae, including Messier 83, which he discovered in 1752 during an expedition to the Cape of Good Hope.
In 1781, Charles Messier added it to his catalog, referring to it as a “nebula without stars,” reflecting the limited understanding of galaxies at the time. It was not until the 20th century, thanks to Edwin Hubble’s work, that astronomers recognized objects like Messier 83 as separate galaxies, far beyond the Milky Way.
This image reveals Messier 83's well-defined spiral arms, densely packed with pink clouds of hydrogen gas, where new stars are forming. These pink areas are mixed with bright blue clusters of hot, young stars, whose ultraviolet radiation has cleared away the surrounding gas.
At the galaxy’s center, a yellow bulge made up of older stars is visible, and a weak bar runs through the core, funneling gas from the outer regions inward. DECam’s high sensitivity allows for detailed views of the galaxy’s extensive halo and the numerous distant galaxies in the background.
While Messier 83 hosts a number of newly formed stars, it also contains a significant number of dying stars. In the past century, scientists have observed six supernovae in Messier 83, a number matched by only two other galaxies. Although only six supernovae have been detected, the galaxy likely contains hundreds of thousands of "ghosts"—supernova remnants—left behind by deceased stars.
In 2006, NSF NOIRLab scientist Ruben Diaz and an international team of astronomers discovered an unusual feature in Messier 83 using the Gemini South telescope, part of the International Gemini Observatory, which is partially supported by the NSF and managed by NSF NOIRLab.
They identified a previously unseen mass concentration resembling a second nucleus at the galaxy’s core. This is likely the remnant of another galaxy merging with Messier 83. This ongoing collision, which may be responsible for the starburst activity, will eventually result in the merging of the two nuclei—likely black holes—into a single nucleus in about 60 million years.