Updated

Updated · spacedaily.com · Jun 29

James Webb Resolves 16.5 Million Stars in M82 as Cigar Galaxy Forms Stars 10 Times Faster

Updated

Updated · spacedaily.com · Jun 29

James Webb Resolves 16.5 Million Stars in M82 as Cigar Galaxy Forms Stars 10 Times Faster

Q: What cosmic ghost will the Cigar galaxy become after its star-making frenzy burns out?

The Cigar galaxy will most likely fade into a post-starburst, then largely quiescent galaxy — the kind astronomers often describe as “red and dead.” That outcome follows from the same forces now making M82 so spectacular. Its starburst is burning through gas at an exceptional rate, while massive young stars and supernovae are driving powerful bipolar outflows that blow gas and dust out of the galaxy. Those winds, combined with fuel consumption, are expected to trigger rapid quenching: a sharp decline in new star formation once the cold molecular gas needed to make stars is exhausted or expelled. Astronomers think M82’s frenzy was likely set off by a close encounter with neighboring M81, which disturbed its disk and funneled gas inward. But starbursts are short-lived on cosmic timescales, lasting only a few hundred million years. After that, M82 should be left dominated by older stars, with little fresh stellar birth. Its exact final shape is less certain. It may remain a disturbed, gas-poor remnant or evolve toward a smoother, more elliptical-looking system. But the broad picture is clear: the “cosmic ghost” of today’s blazing Cigar galaxy is a quieter, aging galaxy whose fireworks have ended, preserving only the fossil record of its brief, violent youth.

3 articles · Updated · spacedaily.com · Jun 29

A 65-hour James Webb survey resolved 16.5 million individual stars in Messier 82, giving astronomers their clearest star-by-star view yet of the nearby Cigar Galaxy.
Webb achieved that by using infrared light to cut through M82’s heavy dust, separating what earlier Hubble and Spitzer images largely saw as a crowded glow.
M82 matters because it is a starburst galaxy, converting gas into stars about 10 times faster than the Milky Way and venting material in two large plumes that show the burst is already disrupting its own fuel supply.
The new image also shows a lopsided disk consistent with a past close encounter or merger, a likely trigger for the current burst, though astronomers say that history is still being reconstructed.
NASA stressed the 16.5 million figure is only the stars Webb could resolve in one image—not a full census—and said the dataset will be combined with Hubble and other observations to map M82’s evolution.

Sources

spacedaily.com15h ago

James Webb Space Telescope Resolves 16.5 Million Stars in Rapidly Forming Cigar Galaxy M82

The Indian Express1h ago

NASA's James Webb telescope reveals millions of hidden stars in 'Cigar' galaxy: Why it matters | Technology News - The Indian Express

News1815h ago

NASA's James Webb Telescope Reveals 16.5 Million Stars In 'Cigar' Galaxy | World News - News18

5 Sources

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JWST’s Deepest Look at M82: 16.5 Million Stars Reveal the Secrets of a Starburst Galaxy

Overview

The James Webb Space Telescope (JWST) has delivered an unprecedented and detailed view of the Cigar Galaxy (M82), using its advanced Near-Infrared Camera to reveal 16.5 million individual stars, intricate dust, and ionized hydrogen gas. These groundbreaking observations mark a major step in understanding M82’s complex structure and evolutionary history. By tracing the galaxy’s past development and ongoing processes, scientists are now able to reconstruct how intense star formation and cosmic feedback shape galaxies. JWST’s ability to see through dense dust provides a clearer picture of M82’s dynamic environment, offering new insights into how galaxies evolve.

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