The asteroid Vesta reaches opposition in Ophiuchus on the 19th of June.
This asteroid was explored by the Dawn Spacecraft between 2011 and 2012, before going on to explore Ceres.
Its current eastwards retrograde movement takes it just south of the open star cluster M23 on the 14th of June.
Its maximum magnitude is about +5.3 at it’s brightest means that it is (theoretically, at least) a naked eye object.
Failing that, binoculars or a small telescope should help you identify this asteroid against the background stars. Its movement over a day or so should reveal its non-stellar nature.
Make a sketch of the star field or take a picture of its position a day or so either side of each other to reveal the asteroids movement.
Happy Hunting.
The map below shows the path during June and July.
Position shown at 1 day intervals.
(Click on map for bigger version).
