Z Camelopardalis (Z Cam) is a
cataclysmic variable
Variable may refer to:
* Variable (computer science), a symbolic name associated with a value and whose associated value may be changed
* Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...
star system in the northern
constellation of
Camelopardalis. 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. Dwa ...
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
The Carte du Ciel (literally, 'Map of the Sky') and the Astrographic Catalogue (or Astrographic Chart) were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue an ...
.[ 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.][
]
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 radiation ...
References
External links
*
G-type main-sequence stars
Dwarf novae
Camelopardalis (constellation)
Camelopardalis, Z
J08251318+7306391
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