  The aging and gradual brightening of the Sun will challenge Earth's
habitability in the next few billion years. If life exists elsewhere in the
Universe, the aging of its host star similarly poses an existential threat. One
solution, which we dub a Lazarus star, is for an advanced civilization to
remove (or star-lift) mass from their host star at a rate that offsets the
increase in luminosity, keeping the flux on the habitable planet(s) constant
and extending the lifetime of their star. While this idea has existed since
1985 when it was first proposed by Criswell, numerical investigations of
star-lifting have been lacking. Here, we use the stellar evolution code MESA to
find mass vs. age and $\dot{M}$ vs. age relations which would hold the flux on
surrounding planets constant. We explore initial mass ranging from $0.2{\rm
M}_{\odot}$ to $1.2{\rm M}_{\odot}$. For most stars with a mass initially below
about $ 0.4 {\rm M}_{\odot}$, we find that star-lifting increases their
main-sequence lifetimes up to $500$ Gyr until they approach the hydrogen
burning limit and star-lifting is no longer possible. For more massive stars,
star-lifting increase main-sequence lifetimes by 1 Gyr to 100 Gyr, though they
still enter the red-giant phase. For example, a Sun-like star has a
main-sequence lifetime which can be increased by up to 3 Gyr. This requires a
mass-loss rate of about $0.05 {\rm M}_{\mathrm{Ceres}}$ per year. We compare
star-lifting to other survival strategies and briefly discuss methods for
detecting these engineered stars.
