NASA’s Chandra X-ray Observatory has uncovered a remarkable object that could be the crucial link between a concealed “black hole star” and a fully visible supermassive black hole, shedding light on the growth of the universe’s earliest giants.
Optical and infrared images from Hubble depict the region around the X-ray dot, while Chandra X-ray images illustrate its surroundings. Image credits: NASA / CXC / Max Plank Inst / Hviding et al. / ESA / STScI / HST / CXC / SAO / N. Walk.
Shortly after the NASA/ESA/CSA James Webb Space Telescope initiated its scientific observations, new reports surfaced regarding a novel class of enigmatic astronomical entities.
Astronomers have identified numerous small red objects situated approximately 12 billion light-years away from Earth, dubbed “little red dots” (LRDs).
Many researchers suspect that LRDs are supermassive black holes encapsulated in dense gas clouds, obscuring features that typically help astronomers detect these celestial objects, including X-rays.
Unlike conventional growing supermassive black holes, which are not surrounded by dense gas, LRDs’ light emissions are hindered, preventing the escape of bright ultraviolet and X-rays from the material orbiting the black hole.
A recently identified “X-ray dot,” located about 11.8 billion light-years from Earth, might serve as a pivotal connection between black hole stars and typical growing supermassive black holes.
This object, known as 3DHST-AEGIS-12014, exhibits characteristics of an LRD—small, red, and distant—but uniquely emits X-ray light.
“Astronomers have been trying to decipher the nature of the little red dot for years,” commented Dr. Raphael Widing from the Max Planck Institute for Astronomy.
“This singular X-ray phenomenon could be the key to connecting all the dots, so to speak.”
This exceptional object was discovered through a comparison of new Webb data against comprehensive previous surveys conducted by Chandra.
“If this little red dot is a rapidly growing supermassive black hole, why does it not emit X-rays like its counterparts?” questioned Dr. Anna de Graaf from Harvard University and the Smithsonian Center for Astrophysics.
“Identifying small red dots that exhibit differing properties from other dots offers crucial new insights into the mechanisms behind their power.”
The researchers propose that this X-ray dot signifies a transitional phase from an LRD to a typical growing supermassive black hole.
As a black hole star consumes gas from its surroundings, gaps in the gas cloud form.
This allows X-rays from the matter descending into the black hole to penetrate and be detected by Chandra.
Ultimately, as the gas is fully consumed, the black hole star will cease to exist.
Chandra’s X-ray dot data also hints at fluctuations in the brightness of the X-rays, supporting the notion of a partially obscured black hole.
As the gas cloud rotates, varying densities of gas encircle the black hole, affecting X-ray brightness.
“If we confirm that the X-ray dot is indeed a small red dot in transition, it could be unprecedented and may reveal the core of a small red dot for the first time,” stated Princeton University’s Hanpu Liu.
“This would also provide strong evidence that a growing supermassive black hole resides at the center of some, if not all, of the tiny red dot population.”
Another hypothesis about the X-ray dot is that it could be a common type of growing supermassive black hole, albeit shrouded in an unusual type of dust yet to be documented.
Future observations are planned to uncover the truth behind this discovery.
“The X-ray dot has been part of our Chandra survey data for over a decade, but we only recognized its significance after Webb observed the region,” remarked Dr. Andy Golding of Princeton University.
“This exemplifies the strength of collaboration between two remarkable observatories.”
This discovery is documented in the following article: paper in Astrophysical Journal Letters.
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Raphael E. Viding et al. 2026. X-ray dots: exotic dust or late-stage tiny red dots? APJL 1000, L18; doi: 10.3847/2041-8213/ae4c88
Source: www.sci.news
