8 in 10 Stars in the Milky Way Bulge Experience Stellar Encounters
  Within 1000 AU in a Gigayear
  The Galactic bulge is a tumultuous dense region of space, packed with stars
separated by far smaller distances than those in the Solar neighborhood. A
quantification of the frequency and proximity of close stellar encounters in
this environment dictates the exchange of material, disruption of planetary
orbits, and threat of sterilizing energetic events. We present estimated
encounter rates for stars in the Milky Way bulge found using a combination of
numerical and analytical methods. By integrating the orbits of bulge stars with
varying orbital energy and angular momentum to find their positions over time,
we were able to estimate how many close stellar encounters the stars should
experience as a function of orbit shape. We determined that ~80% of bulge stars
have encounters within 1000 AU and that half of bulge stars will have >35 such
encounters, both over a gigayear. Our work has interesting implications for the
long-term survivability of planets in the Galactic bulge.
