Question: why is oumuamua speeding up?
Answer: The pull of the Sun's gravity caused it to speed up until it reached its maximum speed of 87.71 km/s (315,800 km/h) as it passed south of the ecliptic on 6 September and made a sharp turn northward at its closest approach to the Sun (perihelion) on 9 September at a distance of 0.255 AU (23,700,000 mi; 38,100,000 km) ...