From a search, I found a list of some preparatory HST observations made for the August 4, 2018 occultation of a star by the asteroid 2014 MU69
We propose observations in support of the upcoming New Horizons encounter for 2014MU69. One visit is for support observations of a star to be occulted by 2014MU69 on 2018 August 4 from which ultra-precise astrometry and shape information about the target can be derived. The second visit is for a backup epoch of astrometry on 2014MU69 itself at the end of the 2018 observing window at a time when New Horizons will also be observing the target. (minor typographical edits made)
Five lines are shown, for measurements between
2018-04-30 01:03 and
01:48. The target is listed as
MU20180804 but that name seems to be the identification of an occultation, not the name of a star.
So far I have not figured out the actual identity of the star that was predicted to be occulted by 2014 MU69 on
Here is a very nice prediction for three occultations by 2014 MU69 last year (2017). However when I go to the main page for that asteroid occultation site and look at
2018-08-04 I don't see any events with MU69 as the asteroid!