Here&#x27;s a link to the Caltech (which runs Palomar and Keck) ToO policy:<p><a href="http:&#x2F;&#x2F;www.astro.caltech.edu&#x2F;observatories&#x2F;coo&#x2F;TOO&#x2F;ToOpolicy.html" rel="nofollow">http:&#x2F;&#x2F;www.astro.caltech.edu&#x2F;observatories&#x2F;coo&#x2F;TOO&#x2F;ToOpolicy...</a><p>You can ask for ToO time (<a href="http:&#x2F;&#x2F;www.astro.caltech.edu&#x2F;observatories&#x2F;coo&#x2F;solicit&#x2F;2016A&#x2F;Call2016A.html" rel="nofollow">http:&#x2F;&#x2F;www.astro.caltech.edu&#x2F;observatories&#x2F;coo&#x2F;solicit&#x2F;2016A...</a>), but it has to be approved as part of the semi-annual solicitation for observing time.  When you use it, you have to notify the PI you bumped and a committee, and later report back to them on the results.<p>Postdocs don&#x27;t have to give up their observing for a ToO, but faculty do.<p>In Caltech&#x27;s policy, interrupted observers don&#x27;t get payback time.