The Vera Rubin Observatory is built, and preparing to start its Legacy Survey of Space and Time. These preparations, with early trials looking okay, are mainly fine tuning of optical parameters and data processes. But there’s a non-main process: targets of opportunity (ToO):
https://gcn.nasa.gov/circulars/42707
Gravity-wave detection S251112cm occurred on November 12, 2025- hence, the encoded name. The LIGO–Virgo–KAGRA combined gravity network localized the gravitational disturbance to some area of the sky. Unlike prior gravity-wave detections, Vera Rubin was operating (in some sense). An executive decision was then made to image inside the LIGO-Virgo-KAGRA area given, which costs time at other areas of the sky. In practice, ToO studies will happen during the general sky survey. The stereotypical ToO event is a supernova alert. Some other observatory or observatories will send an alert, and Rubin will be shunted from other tasks to the supernova location, to track its dimming. If the alert is soon enough, and Vera Rubin quick enough, the supernova’s buildup and peak may be seen.
But there are other ToO justifications, even aside from gravity-wave alerts. Should a new comet or asteroid be deemed ‘interesting’ (Earth-approaching, interstellar, or simply too dim for lesser telescopes), Rubin may also be swung into action. (Assuming, of course, Rubin hadn’t caught the target already by pure chance- this has already happened.) Entire teams have been set up for these ToOs.
I’ve said it before, and I’ll say it again: Vera Rubin will (any day now) be a game-changer.