A pair of white dwarf stars have been discovered in an eclipsing binary system, offering astronomers the first chance to directly measure the radius of a rare white dwarf composed of pure helium.
eclipsing binary system: A binary star system in which the stars eclipse each other.
ecliptic: The apparent path of the sun around the sky.
ejecta: Pulverized rock scattered by meteorite impacts on a planetary surface.
α CrB is an eclipsing binary system similar to Algol (β Per). Its period is 17.36 days, with magnitude varying from +2.21 to +2.32, which is hardly noticeable to the unaided eye.
An eclipsing binary system. The variation of the brightness (the graph at the bottom) due to eclipsing stars depends upon the brightness of the individual stars. When the stars are both visible, the brightness is at a maximum value.
Light curve of an eclipsing binary system
Credit: Swinburne
Light curves of Supernovae
Credit: NASA/CXC/UC Berkeley/N.Smith et al.
a) This light curve is typical of an eclipsing binary system.
b) An eclipsing binary is where two stars alternately eclipse each other. Their orbital plane is side-on or almost side-on to Earth.
The maximum luminosity of an eclipsing binary system is equal to the sum of the luminosity contributions from the individual stars. When one star passes in front of the other, the luminosity of the system is seen to decrease.
Astrophysicists at UC Santa Barbara are the first scientists to identify two white dwarf stars in an eclipsing binary system, allowing for the first direct radius measurement of a rare white dwarf composed of pure helium.
This is called an eclipsing binary system. In the case of an eclipsing binary, we see each star pass directly in front of the other one. In these cases, the masses can be directly determined for the stars.
Figure: See Figure 9-19. In an eclipsing binary system changes in the light curve correspond to various points in the binary orbit. The light drops when one or the other of the stars is eclipsed.
Richardson, an African-American sophomore at Fisk, also majoring in physics as part of the FASST program, has likewise dived head first into astronomy research. His main task has been to process measurements from an eclipsing binary system -- a ...
Castor also has a faint companion star, an eclipsing binary system, which makes it a sextuple system, one composed of hot, bluish-white stars and faint red dwarfs.
Eclipsing Binary: Sometimes, in a binary star system, one star will pass in front of the other producing what we call eclipsing binary. It can be treated as a special kind of visual binary. Eclipsing binary systems are variable stars (see below).
Surprisingly, the more massive of the two also turned out to be the least luminous.K.G. Stassun, R.D. Mathieu and J.A. Valenti, "Discovery of two young brown dwarfs in an eclipsing binary system", Nature, 440, 311-314, 16 March 2006.
Structure ...
 See also: Binary system, Eclipsing Binary, Star, Light, Earth
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