  MAXI J1621-501 is the first Swift/XRT Deep Galactic Plane Survey transient
that was followed up with a multitude of space missions (NuSTAR, Swift,
Chandra, NICER, INTEGRAL, and MAXI) and ground-based observatories (Gemini,
IRSF, and ATCA). The source was discovered with MAXI on 2017 October 19 as a
new, unidentified transient. Further observations with NuSTAR revealed 2 Type I
X-ray bursts, identifying MAXI J1621-501 as a Low Mass X-ray Binary (LMXB) with
a neutron star primary. Overall, 24 Type I bursts were detected from the source
during a 15 month period. At energies below 10 keV, the source spectrum was
best fit with three components: an absorbed blackbody with kT = 2.3 keV, a
cutoff power law with index $\Gamma{}$ = 0.7, and an emission line centered on
6.3 keV. Timing analysis of the X-ray persistent emission and burst data has
not revealed coherent pulsations from the source or an orbital period. We
identified, however, a super-orbital period $\sim{}$78 days in the source X-ray
light curve. This period agrees very well with the theoretically predicted
radiative precession period of $\sim{}$82 days. Thus, MAXI J1621-501 joins a
small group of sources characterized with super-orbital periods.
