Official website page: Successful Deep Space Maneuver

The graph shows the spacecraft speed wrt the Sun during the DSM-1 and the resulting acceleration.

The change in the velocity vector was 431.9 m/s, while the change in the magnitude of the heliocentric velocity was 422.65 m/s.

Official website page: OSIRIS-REx Asteroid Search

Here's the heliocentric mean ecliptic and equinox of J2000 position of the spacecraft and of the fourth Lagrange point (L4) during the "close" encounter on Feb 16. The yellow circle is the Sun.

According to the NAIF's data file, the minimum distance between the two objects was 25 628 797 km at the time 2017-02-16 10:36:06 UTC.

If you hover the mouse over a point, a label appears showing the date and the distance (in millions of kilometers) between the spacecraft (black plot) and L4 (orange plot).

Here's the same as above, but L4-Centered.
The labels also show the spacecraft speed (km/s) wrt L4.