Transits Probabilities Around Hypervelocity and Runaway Stars
  In the blooming field of exoplanetary science, NASA's Kepler Space Telescope
has revolutionized our understanding of exoplanets. Kepler's very precise and
long-duration photometry is ideal for detecting planetary transits around
Sun-like stars. The forthcoming Transiting Exoplanet Survey Satellite (TESS) is
expected to continue Kepler's legacy. Along with transits, the Doppler
technique remains an invaluable tool for discovering planets. The next
generation of spectrographs, such as G-CLEF, promises precision radial velocity
measurements. In this paper, we explore the possibility of detecting planets
around hypervelocity and runaway stars, which should host a very compact system
as consequence of their turbulent origin. We find that the probability of a
multi-planetary transit is $10^{-3}\lesssim P\lesssim 10^{-1}$. We therefore
need to observe $\sim 10-1000$ high-velocity stars to spot a transit. However,
even if transits are rare around runaway and hypervelocity stars, the chances
of detecting such planets using radial velocity surveys is high. We predict
that the European Gaia satellite, along with TESS and the new-generation
spectrographs G-CLEF and ESPRESSO, will spot planetary systems orbiting
high-velocity stars.
