  With a one-dimensional stellar evolution model, we find that massive
main-sequence stars can accrete mass at very high mass accretion rates without
expanding much if they lose a significant fraction of this mass from their
outer layers simultaneously with mass accretion. We assume the accretion
process is via an accretion disk that launches powerful jets from its inner
zones. These jets remove the outer high-entropy layers of the mass-accreting
star. This process operates in a negative feedback cycle, as the jets remove
more envelope mass when the star expands. With the one-dimensional model, we
mimic the mass removal by jets by alternative mass addition and mass removal
phases. For the simulated models of 30Mo and 60Mo, the star does not expand
much if we remove more than about half of the added mass in not-too-short
episodes. This holds even if we deposit the energy the jets do not carry into
the envelope. As the star does not expand much, its gravitational potential
well stays deep, and the jets are energetic. These results are relevant to
bright transient events of binary systems powered by accretion and the
launching of jets, e.g., intermediate luminosity optical transients, including
some luminous red novae, the grazing envelope evolution, and the 1837-1856
Great Eruption of Eta Carinae.
