Astronomers have long been captivated by a mysterious cluster of faint red objects known as “little red dots,” discovered by the NASA/ESA/CSA James Webb Space Telescope. Recently, Vasily Kokolev, an astronomer at the University of Texas at Austin, and his team utilized the Webb’s NIRCam and NIRSpec instruments to capture the deepest spectrum of a tiny red dot, named GLIMPSE-17775, ever recorded. The findings reinforce the theory that this object is a supermassive black hole enveloped in a thick cocoon of partially ionized gas, aligning with the BH* (black hole star) model.
This web image depicts the small red dot GLIMPSE-17775 behind galaxy cluster Abel S1063. Credit: NASA / ESA / CSA / Vasily Kokorev, UT Austin / Alyssa Pagan, STScI.
“There is a growing consensus in the scientific community that this little red dot can be explained by the black hole star model,” said Kokolev.
“However, none of the other little red dots have presented all the necessary evidence together until now.”
“GLIMPSE-17775 provides an exceptional opportunity to test these models due to its remarkable spectrum,” Kokolev added.
With a cosmological redshift of 3.5, GLIMPSE-17775 existed approximately 1.8 billion years after the Big Bang.
This intriguing object came into view serendipitously during Webb’s observations of the galaxy cluster Abel S1063, which aimed to identify Population III stars and faint early galaxies.
Positioned behind the star cluster, the brightness of the small red dot is enhanced through the phenomenon of gravitational lensing.
“When I first examined the spectrum, it felt like I had scattered puzzle pieces on the floor,” Dr. Kokolev remarked.
“We meticulously measured the lines, fitting the pieces together to form a cohesive picture.”
“Some initial fragments that appeared insignificant suddenly revealed a deeper connection.”
The spectroscopic data gathered by Webb contains multiple lines of evidence confirming the interpretation of GLIMPSE-17775 as a black hole star. This phenomenon occurs when a rapidly accreting black hole is shielded by a dense gas cocoon, which modifies the light emitted near the black hole, producing distinct spectral features.
“Everything aligns perfectly, and this adds depth to our understanding of the universe,” Kokolev expressed.
“In the future, I aspire to delve deeper into what powers the core of this little red dot.”
“While we believe it is a black hole, alternative theories are also intriguing and deserve consideration.”
“We anticipate that, within a year or two, we will have a definitive understanding of the energy sources that drive these phenomena.”
Details from the team’s findings will be published in the Astrophysical Journal.
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Vasily Kokolev and colleagues. 2026. Insights into the dense gas cocoon surrounding GLIMPSE-17775. APJ 1004, 153; doi: 10.3847/1538-4357/ae4ed7.
Source: www.sci.news
