Astronomers utilizing the Multi-unit Spectroscopic Explorer (Muse) on ESO’s Very Large Telescope (VLT) captured an active starburst galaxy, NGC 253, in thousands of colors simultaneously.
This VLT/Muse image displays a detailed multi-colored view of NGC 253. Image credit: ESO/Congiu et al.
NGC 253 lies approximately 11.5 million light-years away in the Sculptor constellation.
Commonly referred to as the Silver Coin, Silver Dollar Galaxy, or Sculptor Galaxy, this galaxy was discovered on September 23, 1783, by Caroline Herschel, the sister of William Herschel.
It is one of the brightest members of the Sculptor group of galaxies.
Characterized as a starburst galaxy, it experiences unusually rapid star formation and stellar explosions.
“NGC 253 is one of the largest star-forming galaxies near the Milky Way,” noted ESO astronomer Enrico Kong and his team.
“It also ranks among the largest galaxies in the sky, with apparent dimensions of 42 x 12 arcminutes2.
“With its distinct stellar bars, well-defined spiral arms, and widespread star formation, NGC 253 exemplifies a classic spiral galaxy near the main sequence.”
To create a new image of the galaxy, astronomers dedicated over 50 hours observing it with the VLT’s Muse Instrument.
They needed to stitch together more than 100 exposures to encapsulate an area of approximately 65,000 light-years.
“You can focus on individual regions where stars form at a scale of individual stars, or you can zoom out to view the entire galaxy,” explained Dr. Kathryn Kreckel, an astronomer at the University of Heidelberg.
In their initial data analysis, researchers identified 500 planetary nebulae and regions of gas and dust within NGC 253.
“In areas outside our galaxy, we typically find fewer than 100 detections per galaxy,” remarked Fabian Schuerman, a doctoral student at Heidelberg University.
“Due to the properties of planetary nebulae, they serve as distance markers for host galaxies.”
“By locating the planetary nebulae, we can confirm the distance to the galaxy, which is crucial for other galaxy research.”
“Future projects utilizing maps will investigate gas flows and how their composition influences star formation across this galaxy.”
“It remains a mystery why such a minor process can significantly influence galaxies that are thousands of times larger,” stated Dr. Kong.
The results will be published in the journal Astronomy and Astrophysics.
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E. Congiu et al. 2025. Sculptor’s Muse View of the Galaxy: Overview of the Survey and the Planetary Nebula Luminosity Function. A&A in print;
Source: www.sci.news
