Event Horizon Telescope Pinpoints the Birthplace of the Colossal Jet from Supermassive Black Hole M87*

Astronomers from the Event Horizon Telescope (EHT) collaboration have reached a landmark milestone by identifying the precise origin point of the massive jet emanating from the supermassive black hole M87*. This significant discovery stems from a rigorous analysis of observational data collected during the 2021 EHT campaign. The findings provide the first concrete observational evidence of the exact location where these powerful streams of charged particles are launched into deep space.

Situated at the heart of the Messier 87 (M87) galaxy, roughly 55 million light-years from Earth, the black hole M87* has long been a subject of intense study. While the jet itself is a staggering 3,000 light-years in length, its base had previously remained obscured within the shadow of the black hole. Recent measurements have finally traced this foundation to a compact region located less than one-tenth of a light-year—specifically about 0.09 light-years—from the event horizon of the black hole.

The research involved an international team of experts, including group leader Saurabh from the Max Planck Institute for Radio Astronomy (MPIfR) and team member Hendrik Müller from the National Radio Astronomy Observatory (NRAO). Sebastiano von Fellenberg, currently with the Canadian Institute for Theoretical Astrophysics (CITA) and formerly of MPIfR, also played a vital role in the study, which has been published in the journal Astronomy and Astrophysics. The team determined that specific radio emissions detected in the 2021 dataset, which were notably absent in the 2017–2019 observations, originated from this near-horizon zone, marking the jet's base.

M87* holds a historic place in science as the first black hole to be visually captured, with its iconic shadow image released in April 2019 based on 2017 data. With a staggering mass of approximately 6.5 billion solar masses, it dwarfs Sagittarius A* (Sgr A*), the black hole at the center of our own Milky Way, which is estimated at only 4 million solar masses. To achieve this level of detail, the researchers utilized Very Long Baseline Interferometry (VLBI), a technique that allows for the resolution of cosmic structures on scales approaching the Schwarzschild radius.

The success of this study was bolstered by the integration of new astronomical instruments that significantly enhanced the EHT’s sensitivity. Specifically, the inclusion of the NOEMA array and the 12-meter telescope at Kitt Peak provided essential intermediate baselines, allowing the team to resolve structures at scales between 0.02 and 0.2 parsecs. This technical leap enabled the identification of the jet structure just 0.09 light-years from the black hole, showcasing the evolving precision of the EHT collaboration’s global network.

These findings align with established theoretical frameworks, such as the Blandford-Znajek (BZ) mechanism. This theory proposes that the immense energy required to power such jets is extracted from the rotational energy of the black hole itself, mediated by powerful magnetic fields that cross the event horizon. Looking ahead, the EHT team plans further observations that will be critical in confirming these results and potentially solving the long-standing mystery regarding the fundamental physics that launch these massive galactic jets.