  The detection of a pulsed X-ray counterpart (RX J1824.2-2R52P) of the 3.05 ms
pulsar PSR 1821-24, suggests the possibility of a part of the rotational energy
loss of this high spindown rate pulsar being in the optical band. Archival HST
data for M28 is used here to set upper limits on the optical V-band magnitude
of PSR 1821-24. The optical limit extends the multiwavelength observations for
this source and provides a constraint for theoretical models of pulsar
emission.
