Tidal, Radio & Variable

A close binary in which a white dwarf accretes matter from a companion through a disk, producing recurrent outbursts as the disk brightens — the dwarf novae and related variables of the time-domain sky.

Stars whose brightness changes irregularly through eruptions and flares — from the giant eruptions of luminous blue variables to the flares of young and magnetically-active stars.

Millisecond flashes of radio waves from far across the universe, immensely energetic for their brevity. At least some come from magnetars; most are one-off, though a few repeat. Their dispersion probes the matter between the galaxies.

The flare produced when a star wanders too close to a supermassive black hole and is torn apart by tides, some of its debris blazing as it falls in. TDEs light up otherwise-quiet galactic nuclei for months.