Z Camelopardalis

Z Camelopardalis (Z Cam) is a cataclysmicvariablestar system in the northern constellation of Camelopardalis. It has an apparent visual magnitude which varies between 9.8 and 14.5. This system is the prototype star for the family of Z Camelopardalis variable stars: dwarf novae with standstills at a brightness intermediate between their maxima and minima. It may have been the "guest star" that was recorded by Chinese astrologers in the autumn of 77 BCE, but a 2024 study argues that this guest star was likely a comet, while one observed in 369 CE may have been Z Camelopardalis.

Z Camelopardalis was discovered photographically in 1904 by Henry Park Hollis during work for the Astrographic Catalogue. It is surrounded by an extensive shell thought to have been ejected in a nova explosion, the largest known of its type. The size and expansion of this shell sets a firm lower limit since the last eruption of at least 220 years.