{"id":578629,"date":"2026-08-01T09:39:20","date_gmt":"2026-08-01T09:39:20","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/578629\/"},"modified":"2026-08-01T09:39:20","modified_gmt":"2026-08-01T09:39:20","slug":"star-formation-in-andromeda-our-neighbor-is-winding-down","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/578629\/","title":{"rendered":"Star formation in Andromeda \u2013 our neighbor \u2013 is winding down"},"content":{"rendered":"

\"ObliqueThe galaxy next door appears to be settling in for retirement. NASA said<\/a> on July 27, 2026, that star formation in Andromeda<\/a> is winding down. This image of the Andromeda Galaxy from the Hubble Space Telescope<\/a> shows blue regions with recent star formation (1) along with redder regions with less recent star formation (2). Image via NASA<\/a>\/ ESA\/ Benjamin Williams (UWashington)\/ Zhuo Chen (UWashington)\/ L. Clifton Johnson (Northwestern)\/ Image processing: Joseph DePasquale (STScI).<\/p>\n

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Star formation in Andromeda is winding down<\/p>\n

The Andromeda Galaxy<\/a> is our next door neighbor. It\u2019s the closest large spiral galaxy to the Milky Way, 2.5 million light-years<\/a> away. And on July 27, 2026, NASA said<\/a> star formation in Andromeda is winding down.<\/p>\n

A new study showed that over the past 500 million years, the rate of star formation has been slowing. Plus, there\u2019s been a particularly steep drop over the past 40 million years.<\/p>\n

The Andromeda Galaxy and our Milky Way are the two most massive and dominant galaxies within the Local Group<\/a> of galaxies. Andromeda is about twice as large as the Milky Way, though, and it\u2019s a bit younger than our galaxy. But observing Andromeda provides valuable insight into our Milky Way.<\/p>\n

The researchers published<\/a> their peer-reviewed<\/a> study in The Astrophysical Journal on July 27, 2026.<\/p>\n

Hubble\u2019s view of Andromeda\u2019s stars<\/p>\n

Andromeda is absolutely teeming with stars. Estimates are that it contains some 1 trillion stars. The Hubble Space Telescope<\/a> has mapped much of the galaxy. Two surveys alone mapped 2\/3 of Andromeda\u2019s disk. And these data allowed astronomers to take measurements of 200 million individual stars.<\/p>\n

Co-author Ben Williams<\/a> of the University of Washington said<\/a>:<\/p>\n

We need to measure the individual stars because they are the fossil record of the galaxy\u2019s formation. Hubble is the only telescope that can give you high enough spatial resolution over a large enough area to be able to do that in Andromeda.<\/p>\n

Using the data from Hubble, the team divided these ultra-sharp images into thousands of squares. The length of each side of the square measured 300 light-years. Then they analyzed each of these squares to determine how much star formation was occurring within it.<\/p>\n

Astronomers can tell a star\u2019s general age by assessing its color. Younger and more massive stars are short-lived and bluer. Older and less massive stars that live longer are redder. So, redder squares contain older stars and bluer squares show more star formation.<\/p>\n

Star formation in Andromeda<\/p>\n

Astronomers have calculated that the last time Andromeda saw a big burst of star formation was about 2 billion years ago. It likely happened after an interaction or merger with another galaxy. The tidal forces push gases together, which can then coalesce and trigger star formation.<\/p>\n

So astronomers can calculate the rate of star formation by how much gas and dust can convert into stars. And they found that, 500 million years ago, Andromeda was forming stars at a rate of about one solar mass per year. That might not seem like much. But it fell even lower around 40 million years ago, to about half that rate. And now, scientists said, Andromeda is only cooking up stars at a rate of about 1\/5 the mass of our sun per year.<\/p>\n

Most of the star-forming activity has been in a ring about 32,000 light-years from the galaxy\u2019s center. It\u2019s that activity that is now slowing over time. <\/p>\n

Watch how star formation slows over time in the Andromeda Galaxy. Brighter colors indicate where star formation was highest during a given time. Video via Tobin Wainer (UWashington); Image Processing: Joseph DePasquale (STScI); Video: NASA, ESA, STScI, Gregory Bacon (STScI).<\/p>\n

Why is star formation dying down?<\/p>\n

Astronomers were curious to know if one of its satellite galaxies, M32, might be playing a role in the slowing of its star formation. M32 is a dwarf satellite galaxy that appears as a fuzzy oval next to Andromeda in images. Astronomers are unsure how much these two galaxies \u2013 separated by 16,000 light-years \u2013 have interacted in the past.<\/p>\n

Co-author Zhuo Chen<\/a> of the University of Washington said:<\/p>\n

One of the major motivations for this program was to probe potential interactions between M32 and Andromeda\u2019s disk.<\/p>\n

What they found was the region of Andromeda closest to M32 did show signs of decreased star formation compared with other regions. And the timing of this decrease extends to about 60 million years ago. Wainer said: <\/p>\n

We can\u2019t explicitly say that we are seeing a decrease in star formation because of M32. But it\u2019s right there, and it\u2019s definitely the most likely suspect.<\/p>\n

\"ObliqueView at EarthSky Community Photos<\/a>. | Shaurya Salunkhe<\/a> in Velhe, Maharashtra, India, used a telephoto lens to capture this view of Messier 31, the Andromeda Galaxy, on January 11, 2026. Shaurya wrote: \u201cI captured the Andromeda Galaxy, the Milky Way\u2019s<\/a> closest neighbor and the largest galaxy of the Local Group<\/a>. This is the farthest object that is visible to the unaided eye.\u201d Thank you, Shaurya! M32 is the little fuzzy oval near the galaxy at lower right.
\nWhat\u2019s next?<\/p>\n

Next, the team plans to combine ground-based observations with the Hubble data. They\u2019re hoping to learn even more about our next door neighbor. Co-author Raja GuhaThakurta<\/a> of the University of California Santa Cruz said:<\/p>\n

There\u2019s a strong scientific value to this archival data. Andromeda is important because it\u2019s a neighbor that is close enough that we can see it in great detail while also getting a global perspective.<\/p>\n

With the upcoming Nancy Grace Roman Space Telescope<\/a>, astronomers hope to get an even better look at the giant spiral next door. Roman\u2019s field of view is around 100 times as large as Hubble\u2019s with a single observation. One of Roman\u2019s observing programs will be to image Andromeda\u2019s entire disk and parts of its halo. This will give astronomers hundreds of millions of more stars to analyze.<\/p>\n

Bottom line: Star formation in Andromeda \u2013 the giant spiral next door to us \u2013 is winding down, astronomers said. And it could be related to M32, the dwarf satellite galaxy that lies nearby.<\/p>\n

Source: The Panchromatic Hubble Andromeda Southern Treasury (PHAST). II. The Spatially Resolved Recent Star Formation History in M31<\/a><\/p>\n

Via NASA<\/a><\/p>\n

Kelly Kizer Whitt
\n View Articles<\/a><\/p>\n

About the Author:<\/p>\n

Kelly Kizer Whitt – EarthSky\u2019s nature and travel vlogger on YouTube – writes and edits some of the most fascinating stories at EarthSky.org. She’s been writing about science, with a focus on astronomy, for decades. She began her career at Astronomy Magazine and made regular contributions to other outlets, including AstronomyToday and the Sierra Club. She has nine published books, including a children’s picture book, Solar System Forecast, and a young adult dystopian novel, A Different Sky.<\/p>\n