> What happens if someone has scheduled time with the telescope. Do they get bumped? Who has priority? Yes they generally get bumped and they will generally g

> What happens if someone has scheduled time with the telescope. Do they get bumped? Who has priority? Yes they generally get bumped and they will generally get that time back later on in the telescope schedule. Folks who do these "target of opportunity" proposals apply like usual, but don't specify targets. If awarded time, they get the ability to "trigger" their observations once an interesting target appears. So their time allocation is (generally) capped like everyone else's, but isn't scheduled. So presumably the people who get bumped will have their observations rescheduled for later. In detail the question of priority is a bit more complicated, and sometimes the people observing can refuse to be bumped for a TOO, but that varies with the observatory and their rules. Edit: Also, people are frequently happy to even "donate" a little bit of their telesocpe time to observe interesting transient sources (sometimes in exchange for co-authorship or acknowledgements in papers, sometimes not). This is partly because astronomy is a reasonably friendly field. And it's also because we can't design and carry out experiments like other fields of science – we have to take what the Universe gives us. So it's good to take advantage of opportunities to view interesting and new sources when they happen.