{"id":69128,"date":"2025-10-10T03:04:13","date_gmt":"2025-10-10T03:04:13","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/69128\/"},"modified":"2025-10-10T03:04:13","modified_gmt":"2025-10-10T03:04:13","slug":"webb-glimpses-doomed-star-before-its-explosion","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/69128\/","title":{"rendered":"Webb glimpses doomed star before its explosion"},"content":{"rendered":"

\"DoomedThis image shows a combined James Webb Space Telescope<\/a> and Hubble Space Telescope<\/a> view of the spiral galaxy NGC 1637. It is located some 40 million light-years<\/a> away. The box in the lower right (enlarged in the upper right) shows the doomed star, a supernova<\/a> known as SN2025pht. Image via Northwestern<\/a>\/ NASA\/ ESA\/ CSA\/ STScI\/ Charles Kilpatrick and Aswin Suresh (Northwestern).<\/p>\n

The article below is taken from a release by Northwestern University on October 8, 2025. Edits by EarthSky.<\/a><\/p>\n

Will this doomed star solve a decades-old mystery?<\/p>\n

Scientists at Northwestern University said on October 8, 2025, that they\u2019ve captured the most detailed glimpse yet of a doomed star before it exploded. And, they said, this star is the dustiest and reddest supernova progenitor<\/a> \u2013 or source star \u2013 yet observed.<\/p>\n

Astronomers detected the supernova<\/a>, dubbed SN2025pht, on June 29, 2025. The Northwestern research team then studied earlier James Webb Space Telescope<\/a> imagery of the galaxy in which the supernova was spotted to identify the progenitor star. They said:<\/p>\n

These observations \u2013 combined with archival images from the Hubble Space Telescope \u2013 revealed the explosion came from a massive red supergiant<\/a> star, cloaked in an unexpected shroud of dust.<\/p>\n

This marks the first time a supernova\u2019s source star has been identified at mid-infrared<\/a> wavelengths. <\/p>\n

The researchers said the discovery might help solve the decades-old mystery of why massive red supergiants are rarely seen to explode. That\u2019s surprising, because scientists\u2019 models predict these kinds of stars should make up the majority of core-collapse supernovae. That\u2019s when massive stars, typically over eight times more massive than our sun, explode because their iron cores can no longer hold out against the force of gravity. <\/p>\n

The new study suggests these stars do explode, but are simply hidden out of sight within thick clouds of dust. With Webb\u2019s new capabilities, astronomers can finally pierce through the dust to spot these phenomena, closing the gap between theory and observation.<\/p>\n

The peer-reviewed<\/a> study was published<\/a> on October 8, 2025, in The Astrophysical Journal Letters.<\/p>\n

\"3These images show views from the Webb and Hubble space telescopes of a red supergiant<\/a> star before and after it exploded. The star is not visible in the Hubble image before the explosion, but appears in the Webb image. The July 2025 view from Hubble shows the glowing aftermath of the explosion. Image via Northwestern<\/a>\/ NASA\/ ESA\/ CSA\/ STScI\/ Charles Kilpatrick and Aswin Suresh (Northwestern).
\nMeet researchers Charlie Kilpatrick and Aswin Suresh<\/p>\n

Northwestern\u2019s Charlie Kilpatrick led the study. He explained:<\/p>\n

For multiple decades, we have been trying to determine exactly what the explosions of red supergiant stars look like. Only now, with [the Webb Space Telescope], do we finally have the quality of data and infrared observations that allow us to say precisely the exact type of red supergiant that exploded and what its immediate environment looked like. <\/p>\n

We\u2019ve been waiting for this to happen, for a supernova to explode in a galaxy that Webb had already observed. <\/p>\n

We combined Hubble and Webb data sets to completely characterize this star for the first time.<\/p>\n

Kilpatrick is an expert on the lives and deaths of massive stars. He\u2019s a research assistant professor at Northwestern\u2019s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA<\/a>). <\/p>\n

Another key coauthor on the paper is Aswin Suresh<\/a>. He is a graduate student in physics and astronomy at Northwestern\u2019s Weinberg College of Arts and Sciences and member of Kilpatrick\u2019s research group.<\/p>\n

\"SmilingCharlie Kilpatrick<\/a> led the study. He is a research assistant professor at Northwestern\u2019s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). His research focuses on observing the life and death of massive stars and the extreme variability, mass loss, luminous explosions and compact remnants they leave behind. He leads time-domain<\/a> programs in optical and infrared<\/a> to search the local universe for these signatures, primarily using telescopes in Arizona, Hawaii and Chile. Image via Northwestern<\/a>.
\n\"VeryAswin Suresh<\/a> is a graduate student in physics and astronomy and a member of Kilpatrick\u2019s research group. He is a key co-author on the paper about SN2025pht. Image via Northwestern<\/a>.
\nReddest, dustiest progenitor ever observed<\/p>\n

The astronomers first detected the supernova on June 29, 2025, using the All-Sky Automated Survey of Supernovae<\/a>. They dubbed it SN2025pht. Its light had traveled from a nearby galaxy called NGC 1637, located 40 million light-years away from Earth.<\/p>\n

By comparing Hubble and Webb images of the galaxy NGC 1637 \u2013 from before and after the star\u2019s explosion \u2013 Kilpatrick, Suresh and their collaborators found SN2025pht\u2019s progenitor star. It was immediately striking because it was extremely bright and incredibly red. The star shined about 100,000 times more brightly than our sun. But a surrounding dust obscured much of this light. The dusty veil was so thick, in fact, that the star appeared more than 100 times dimmer in visible light than it would appear without the dust. <\/p>\n

Because dust blocked out shorter, bluer wavelengths of light, the star also appeared surprisingly red. Suresh commented:<\/p>\n

It\u2019s the reddest, dustiest red supergiant that we\u2019ve seen explode as a supernova.<\/p>\n

Massive stars in the late stages of their lives, red supergiants are among the largest stars in the universe. When their cores collapse, they explode as Type II supernovae<\/a>, leaving behind either a neutron star<\/a> or a black hole<\/a>. <\/p>\n

The most familiar example of a red supergiant is Betelguese<\/a>. It is the bright reddish star in the shoulder of the constellation Orion.<\/p>\n

Kilpatrick added<\/p>\n

SN2025pht is surprising because it appeared much redder than almost any other red supergiant we\u2019ve seen explode as a supernova. That tells us that previous explosions might have been much more luminous than we thought because we didn\u2019t have the same quality of infrared data that JWST can now provide.<\/p>\n

Clues hidden in dust<\/p>\n

The deluge of dust could help explain why astronomers have struggled to find red supergiant progenitors. Indeed, most massive stars that explode as supernovae are the brightest and most luminous objects in the sky. So, theoretically, they should be easy to spot before they explode. But that hasn\u2019t been the case.<\/p>\n

In addition, astronomers posit that the most massive aging stars also might be the dustiest. These thick cloaks of dust might dim the stars\u2019 light to the point of utter undetectability. And now, the new Webb observations support this hypothesis. Kilpatrick said:<\/p>\n

I\u2019ve been arguing in favor of that interpretation, but even I didn\u2019t expect to see such an extreme example as SN2025pht. It would explain why these more massive supergiants are missing because they tend to be dustier.<\/p>\n

In addition to the presence of dust itself, the dust\u2019s composition was also surprising. While red supergiants tend to produce oxygen-rich, silicate<\/a> dust, this star\u2019s dust appeared rich with carbon. This suggests that powerful convection in the star\u2019s final years may have dredged up carbon from deep inside, enriching its surface and altering the type of dust it produced. Kilpatrick added:<\/p>\n

The infrared wavelengths of our observations overlap with an important silicate dust feature that\u2019s characteristic of some red supergiant spectra. This tells us that the wind was very rich in carbon and less rich in oxygen, which also was somewhat surprising for a red supergiant of this mass.<\/p>\n

A new era for exploding stars?<\/p>\n

The new study marks the first time astronomers have used the Webb telescope to directly identify a supernova progenitor star. And they say this fact opens the door to many more discoveries. By capturing light across the near- and mid-infrared spectrum, they said, the Webb can reveal hidden stars and provide missing pieces for how the most massive stars live and die.<\/p>\n

Now, the team said they\u2019re searching for similar red supergiants that may explode as supernovae in the future. Observations by NASA\u2019s upcoming Nancy Grace Roman Space Telescope<\/a> might help this search. Roman will have the resolution, sensitivity and infrared wavelength coverage to see these stars and potentially witness their variability as they expel out large quantities of dust near the end of their lives. Kilpatrick said:<\/p>\n

With the launch of the Webb telescope and upcoming Roman launch, this is an exciting time to study massive stars and supernova progenitors. The quality of data and new findings we will make will exceed anything observed in the past 30 years.<\/p>\n

Bottom line: For decades, astronomers have wanted to know exactly what the explosion of a doomed star \u2013 a red supergiant due to go supernova \u2013 looks like. The Webb Space Telescope has made that knowledge possible.<\/p>\n

Source: The Type II SN 2025pht in NGC 1637: A Red Supergiant with Carbon-rich Circumstellar Dust as the First JWST Detection of a Supernova Progenitor Star<\/a><\/p>\n

Via Northwestern Now<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"This image shows a combined James Webb Space Telescope and Hubble Space Telescope view of the spiral galaxy…\n","protected":false},"author":2,"featured_media":69129,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":["post-69128","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/69128","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=69128"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/69128\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/69129"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=69128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=69128"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=69128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}