The James Webb Space Telescope has revealed BiRD, a bright infrared source hosting a supermassive black hole of roughly 100 million solar masses that was active during cosmic noon (about 4 billion years after the Big Bang). JWST NIRCam spectra show Paschen γ and helium features, enabling distance and mass estimates; BiRD’s light traveled ~10 billion years to Earth. BiRD belongs to the class of “little red dots” — infrared-bright but X-ray faint objects that may be dusty, growing black‑hole seeds. The discovery, published Oct. 30 in Astronomy & Astrophysics, highlights JWST’s power to reveal hidden populations and motivates follow-up studies of nearby LRDs.
JWST Unveils “BiRD”: a 100‑Million‑Solar‑Mass ‘Big Red Dot’ from Cosmic Noon
The James Webb Space Telescope has revealed BiRD, a bright infrared source hosting a supermassive black hole of roughly 100 million solar masses that was active during cosmic noon (about 4 billion years after the Big Bang). JWST NIRCam spectra show Paschen γ and helium features, enabling distance and mass estimates; BiRD’s light traveled ~10 billion years to Earth. BiRD belongs to the class of “little red dots” — infrared-bright but X-ray faint objects that may be dusty, growing black‑hole seeds. The discovery, published Oct. 30 in Astronomy & Astrophysics, highlights JWST’s power to reveal hidden populations and motivates follow-up studies of nearby LRDs.
13:21, 05.11.2025Science
JWST Unveils “BiRD”: a 100‑Million‑Solar‑Mass ‘Big Red Dot’ from Cosmic Noon
Using the James Webb Space Telescope (JWST), astronomers have identified an unusually bright infrared source they nickname BiRD (Big Red Dot) — a supermassive black hole with a mass of roughly 100 million times that of the Sun that shone during the era known as cosmic noon (about 4 billion years after the Big Bang). The discovery, made with JWST’s Near-Infrared Camera (NIRCam), may help researchers understand how supermassive black holes grow and why some elude detection in X-rays.
BiRD was detected near the well-studied quasar J1030+0524 (J1030) in images and spectra analyzed by a team from the National Institute for Astrophysics (INAF). The source is bright in the infrared but was absent from earlier X-ray and radio catalogs — a defining trait of a growing class of compact infrared objects dubbed “little red dots” (LRDs).
Spectroscopic analysis revealed clear signatures of hydrogen (notably the Paschen γ line) and helium absorption features. Those spectral fingerprints allowed the team to estimate the object’s distance and infer the central black hole’s mass at about 100 million solar masses. Light from BiRD has been traveling for roughly 10 billion years, putting its activity near the epoch of cosmic noon.
“Starting from the calibrated images, a catalog of the sources present in the field was developed. It was there that we noticed BiRD: a bright, point-like object that was not a star and did not appear in existing X-ray and radio catalogs,” said Federica Loiacono, the INAF research fellow who led the analysis. “The spectrum let us determine its composition and estimate the black hole mass.”
Little red dots are compact, infrared-bright objects with puzzling spectroscopic properties. A leading hypothesis is that many LRDs are actively accreting — and therefore growing — supermassive black holes. The puzzle is that such accretion typically produces strong X-ray emission, yet BiRD and many other LRDs are faint or undetected in X-rays.
One plausible explanation is heavy obscuration: BiRD-like objects may be massive black-hole “seeds” still enshrouded in dense gas and dust. Thick cocoons absorb high-energy X-rays while allowing longer-wavelength infrared light to escape, making these objects especially visible to JWST’s infrared instruments but not to earlier X-ray surveys.
BiRD resembles two other LRDs found at similar cosmic distances: the team reports comparable spectral line widths, absorption characteristics, estimated black hole masses and gas densities. That similarity suggests BiRD belongs to a recognizable family of sources and indicates LRDs were still relatively common during cosmic noon — contrary to previous expectations that they would have largely disappeared by that epoch.
The researchers emphasize the need to expand the sample of nearby LRDs, which can be studied in greater detail, to better understand their nature and role in black hole growth. JWST’s sensitivity in the infrared is opening a new window on previously hidden populations in the early universe.
The team’s results were published on Oct. 30 in the journal Astronomy & Astrophysics.