Deep inside molecular clouds hide natural amplifiers — cosmic masers. They work like lasers but in the radio band: excited molecules collectively emit waves of a single frequency, creating a bright beam. The catch is that these molecules often have several ways to shed energy. One leads to amplification, while another, like a hole in a bucket, quickly drains the reservoir uselessly. You'd think a fast leak would empty the upper level and kill the maser. But nature is trickier than that.
The authors built a model of a three-level system for a typical case — a methanol maser at 6.7 GHz. Its upper level can also decay at 239.7 GHz, and that decay is four hundred thousand times faster. It turns out that such a leak doesn't suppress maser amplification. What matters is the overall reservoir of excited molecules at the upper level. If it's large enough, the working transition keeps amplifying radiation, while the parasitic channel stays nearly dark. Moreover, with sufficient initial coherence among molecules, the system can produce a short, ultra-powerful burst — superradiance.
The model was applied to a real flare in the star-forming region S255IR-NIRS3. Even with the fast leak, the flare fits the superradiance scenario. So a leaky bucket is no problem, the key is having enough water.
Methanol masers in space can be millions of times brighter than the Sun, if measured only at their working frequency.