We report on the optical identification of the companion star to the eclipsing millisecond pulsar PSR J1824-2452H in the galactic globular cluster M28 ( NGC 6626 ) .
This star is at only 0.2 \arcsec from the nominal position of the pulsar and it shows optical variability ( \sim 0.25 mag ) that nicely correlates with the pulsar orbital period .
It is located on the blue side of the cluster main sequence , \sim 1.5 mag fainter than the turn-off point .
The observed light curve shows two distinct and asymmetric minima , suggesting that the companion star is suffering tidal distortion from the pulsar .
This discovery increases the number of non-degenerate MSP companions optically identified so far in globular clusters ( 4 out of 7 ) , suggesting that these systems could be a common outcome of the pulsar recycling process , at least in dense environments where they can be originated by exchange interactions .