Not far from Tau Ceti is the prototype star for a class of red dwarf stars that can dramatically brighten in a very short period of time. This is UV Ceti. These are sometimes referred to as Flare Stars.
These are red dwarf stars with a mass of only a few tenths of that of the Sun. They are much cooler and dimmer than the Sun. Due to them being very faint they are not easily found and most are seen within 50 or so light years from the Sun.
UV Ceti is about 8.4 light years distant and normally is of magnitude 12 however it has been known to flare up in brightness to magnitude 6.8 in around 20 seconds before fading away again.
It is thought that this brightening could be caused by massive flares on these stars. These flares are totally unpredictable and at most will only last for a few minutes. If you are looking in near Tau Ceti through binoculars and suddenly a star appears you could be watching a flare from UV Ceti.