  In this short letter, we find that a magnetic transition dipole moment
between tau and sterile neutrinos can account for the XENON1T excess events.
Unlike the ordinary neutrino dipole moment, the introduction of the new sterile
mass scale allows for astrophysical bounds to be suppressed. Interestingly, the
best-fit regions that are compatible with the SN1987A imply either boron-8 or
CNO neutrinos as the source flux. We find that sterile neutrinos of either
$\sim$ 260 keV or in the $\sim$(500 - 800) keV mass range are capable of
evading astrophysical constraints while being able to successfully explain the
XENON1T event rate. The sterile neutrino in the best fit parameter space may
have significant effects on big bang nucleosynthesis (BBN). We show the region
in which a low reheating temperature of the Universe may allow the BBN
constraints to be alleviated.
