Hubble captures massive ‘superbubble’ in nearby galaxy

NASA and the European Space Agency have released a striking new image from the Hubble Space Telescope revealing a massive "superbubble" carved into a nebula in the Large Magellanic Cloud, one of the Milky Way's closest galactic neighbors.

The image, published on September 3, shows the nebula LHA 120-N44, located in the constellation Dorado about 160,000 light-years from Earth. At its center sits a vast void — the superbubble — spanning roughly 210 by 140 light-years across, a cavity so large it dwarfs the distance between our sun and Pluto many times over.space+1

How the Superbubble Formed

Scientists believe the stars clustered at the center of the void are responsible for its creation. Through powerful stellar winds and supernova explosions, these stars expelled much of the gas from which they were born. That displaced gas then compressed into a dense, dusty shell surrounding the bubble, now visible as the colorful perimeter framing the dark central cavity.siliconrepublic+1

New stars continue to form within this compressed gas shell, making N44 what NASA describes as "a highly active star birth site". Astronomers previously identified a possible five-million-year age difference between stars inside the superbubble and those forming at its rim.siliconrepublic

A Census of Half a Million Stars

The image derives from Hubble observing program #14689, led by principal investigator Gouliermis, which conducted a census of N44's stellar population. Hubble catalogued nearly half a million stars within and around the cluster, of which roughly 30,000 are pre-main-sequence stars — young objects that have not yet begun fusing hydrogen into helium in their cores.phys+1

The deep blue region toward the bottom-right of the superbubble marks one of the hottest areas of the nebula and the site of its most intense star formation. A separate, smaller bubble known as N44F is visible in the upper-right corner of the image, blown by the stellar winds of a single hot, massive star.siliconrepublic+1

Why N44 Matters

N44 spans about 1,000 light-years overall and qualifies as an emission nebula, meaning its gas has been energized by ultraviolet radiation from nearby massive stars. As the ionized gas cools, it releases energy that causes the nebula to glow, producing the vivid colors in the Hubble portrait.space+1

Astronomers are using the data to understand how long the process takes from the collapse of cold gas clouds into dense knots to the moment nuclear fusion ignites inside a newborn star. Because the Large Magellanic Cloud is relatively poor in elements heavier than helium — conditions similar to galaxies in the early universe — Hubble's observations of N44's lowest-mass stars open a window into star formation under conditions that once prevailed across the cosmos.phys