At the center of galaxy VV 340a lies a supermassive black hole — an object with gravity so strong that even light cannot escape it. It emits a relativistic jet: a narrow stream of matter accelerated to near-light speeds. This jet does not keep a constant direction; its axis traces a cone, much like the axis of a slowing spinning top. Such a pattern is called precession. A full precession cycle takes about 820,000 years. The cause lies in the accreting material — gas and dust falling onto the black hole. This infalling material is not uniformly swirling, so the angular momentum is transferred in jerks, causing the jet to wobble.

The precessing jet acts like a giant 'fan', pushing hot gas out of the galaxy. Each year, about 19 solar masses of material are lost this way. This gas includes hydrogen, which, due to extreme heating, becomes ionized and glows intensely. This glow allows the use of spectral analysis — a method that splits radiation into wavelengths and reveals Doppler shifts of lines. From the shift, scientists determine the gas's radial velocity. Measurements show that gas is carried thousands of light-years from the galaxy's center.

The swept-out gas is the raw material for forming new stars. When the jet carries it beyond the galaxy, the reservoir for star formation is depleted, and the process fades. Thus, even a relatively modest black hole can govern the evolution of a huge stellar system, suppressing the birth of new stars.