Black Hole Jet Makes a Sharp Turn express
The black hole in GRS 1915+105 behaves like a lighthouse with a shaky foundation: its jet, normally aimed in one direction, suddenly veered off by 34 degrees in just a month. Astronomers spotted this during a radio burst in 2025. It turns out that since 2023, the "beam" had been wandering within a 70-degree range, but the abrupt jump in 37 days set a record. The reason is a warped gas disk around the hole. Like a tilted lighthouse support, it wobbles and makes the jet swerve. X-ray observations show that the disk is even irregularly shaped inside, causing the jet to fan out sideways. The jet itself races at nearly light speed, creating the illusion of superluminal motion — an optical trick due to its direction toward us. This discovery, made in our own Galaxy, brings us closer to understanding how black holes eject matter.
Original abstract
as written by the authors arXiv:2606.16228
We report large day-timescale variations in the orientation of the southeast--northwest jet in the prototype microquasar GRS 1915+105. These results are based on three-epoch East Asia VLBI Network (EAVN) observations at 6.7 GHz, obtained during giant radio flares in 2025 detected by the RATAN-600 monitoring program. Our observations reveal the smallest position angle (PA) of $$118^\circ \pm 7^\circ$$ ever measured for the jet in GRS 1915+105, which increases to $$152^\circ \pm 2^\circ$$ within 37 days. Based on the literature results, we further suggest that the jet orientation has exhibited significant variations over a PA range of $$118^\circ$$--$$188^\circ$$ since 2023. This unusual jet orientation behavior in GRS 1915+105 during its current X-ray-obscured state may arise from a warped, precessing inner accretion disk, as implied by recent X-ray spectroscopy. Notably, one image reveals a peculiar morphology in GRS 1915+105, which likely indicates lateral spreading of the approaching southeast jet. Future observations are essential to clarify the issues raised in this work.
Jets from such systems can appear to move faster than light — an optical illusion caused by their direction nearly pointing our way.
In Star Trek, black holes fire straight beams, but in reality their jets perform unexpected pirouettes.