Z Camelopardalis (Z Cam) is a

cataclysmic Cataclysm is derived from the Greek (), 'down, against', and (), 'wash over, surge'. It may refer to: Common meanings *Generally, any large-scale disaster *Deluge (mythology) *Doomsday event, see hypothetical risks to civilization, humans, and ...

variable

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

system in the northern constellation of

Camelopardalis Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative fo ...

. It has an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

which varies between 9.8 and 14.5. This system is the prototype star for the family of Z Camelopardalis variable stars:

dwarf nova A U Geminorum-type variable star, or dwarf nova (pl. novae) is one of several types of cataclysmic variable star, consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion. ...

e with standstills at a brightness intermediate between their maxima and minima. It may be the same bright nova that was recorded by Chinese astrologers in the autumn of 77 BCE. 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 A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

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.

Gallery

File:Z Camelopardalis light curve.png, Z Camelopardalis

light curve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

showing a characteristic standstill interrupting the otherwise regular eruptions File:Gas Shell Around Z Cam.jpg, Gas shell Around Z Camelopardalis File:Z Camelopardalis GALEX.jpg, Z Camelopardalis in

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiati ...

References

External links

* G-type main-sequence stars Dwarf novae Camelopardalis (constellation) Camelopardalis, Z J08251318+7306391 {{var-star-stub