Data from: A pulsar-helium star compact binary system formed by common envelope evolution

A stellar common envelope occurs in a binary system when the atmosphere of
an evolving star expands to encompass an orbiting companion object. Such
systems are predicted to evolve rapidly, ejecting the stellar envelope and
leaving the companion in a tighter orbit around a stripped star. We use
radio timing to identify a pulsar, PSR J1928+1815, with a spin period of
10.55 ms in a compact binary system with an orbital period of 3.60 hours.
The companion star has 1.0 to 1.6 solar masses and eclipses the pulsar for
about 17% of the orbit, so is most likely a stripped helium star but is
undetected at other wavelengths. We interpret this system as having
recently undergone a common envelope phase, producing a compact binary.