Answer the following about hypervelocity stars, for 10 points each.
[10e] Hypervelocity stars are typically defined as exceeding this velocity, the velocity required for an object to overcome a central body’s gravity.
ANSWER: escape velocity
[10h] Hypervelocity stars are generated from the three-body interaction between a supermassive black hole and a binary system in a mechanism named for this astronomer. He names the hypothesized circumstellar disk that spans the interior of the Oort cloud.
ANSWER: Jack G. Hills [or Hills cloud; reject “Hill” or “Hill sphere”]
[10m] Most hypervelocity stars were discovered by this now-retired ESA telescope, which was the successor to the Hipparcos mission. Its third data release includes data on nearly 2 billion stars, making it the most comprehensive survey of the Milky Way.
ANSWER: Gaia
<GC, Other Science>