  Prompted by X-ray detections from multiple surveys, we investigated the
A-type star HD 63021 and found that it is a double-lined spectroscopic binary
with highly variable emission associated with the primary star. Analysis of our
multi-epoch spectroscopic observations, the majority of which were carried out
on small aperture telescopes, indicates a very short orbital period of just
$2.9$ days, and a mass ratio M$_2$/M$_1$ of $0.23$. The A1 V star is a slow
rotator, with a rotational speed of $\sim34$ km/s. Assuming its mass is $2.3$
M$_{\odot}$, the present-day secondary is an evolved star of $\sim0.5$
M$_{\odot}$ that nearly fills its Roche lobe. This secondary star rotates
comparatively rapidly at $\sim44$ km/s, and we see evidence that it is
chromospherically active. Analysis of a photometric lightcurve from TESS
reveals two strong periods, one at the orbital period for the system and
another at half the orbital period. These findings suggest that HD 63021 is a
close binary system undergoing mass transfer from the secondary star onto the
primary star -- in all ways like an Algol eclipsing binary system, except
without the eclipse. We discuss the system's mass transfer, which is not steady
but seems to run in fits and bursts, and infer the system's basic physical
properties from an orbital parameter study, the Roche lobe geometry, and its
extant X-ray emission.
