What is a cataclysmic variable binary star?


What is a cataclysmic variable binary star?

Cataclysmic Variable stars (CVs) are binary star systems where an ultra-dense star (a white dwarf) pulls material off of its companion star, steadily consuming it over time.

What are the variables listed on the H-R diagram?

The Hertzsprung-Russell (H-R) Diagram: changes also – so the H-R diagram can also be thought of as a graphical plot of stellar evolution. From the location of a star on the diagram, its luminosity, spectral type, color, temperature, mass, age, chemical composition and evolutionary history are known.

Where on the H-R diagram will you find variable stars?

The Mira instability strip on the H-R diagram is located in a region between mid-sized stars on the main sequence and the giant branch. Semiregular variables are giants and supergiants showing periodicity accompanied by intervals of semiregular or irregular light variation.

What are the 3 categories of stars on the H-R diagram?

The group called the main sequence extends in a rough diagonal from the upper left of the diagram (hot, bright stars) to the lower right (dim and cool). Large, bright, though cool, stars called giants and supergiants appear in the upper right, and the white dwarfs, dim, small, and hot, lie in the lower left.

What causes cataclysmic variables?

There are two principal energy sources in a cataclysmic variable: accretion and nuclear fusion. Since the white dwarf is very dense, the gravitational potential energy is enormous, and it is converted into X-rays during the accretion process.

Are cataclysmic variable stars common?

Cataclysmic variables have much in common with X-ray binaries, and are often brighter at X-ray and ultraviolet wavelengths than in the optical universe. The X-rays are produced by the extreme temperatures generated where the accretion disk hits the surface of the white dwarf.

What are the independent and dependent variables of the HR diagram?

Manipulated (independent) variable of the HR diagram. Also tells color and spectral class. The amount of light a star releases. Responding (dependent) variable of the HR diagram.

What variable is on the Y axis on an HR diagram?

In a true HR diagram, you would plot the effective temperature of a star on the X-axis and the luminosity of a star on the Y-axis.

Are variable stars on the main sequence?

Eruptive variable stars: They include protostars, which in the process of becoming main sequence stars, often have variations in their brightness.

What does HR diagram tell us about stars?

The Hertzsprung-Russell diagram shows the relationship between a star’s temperature and its luminosity. It is also often called the H-R diagram or colour-magnitude diagram. The chart was created by Ejnar Hertzsprung and Henry Norris Russell in about 1910.

What types of phenomena are considered cataclysmic variables?

Cataclysmic variables (CVs) are binary star systems that have a white dwarf and a normal star companion. They are typically small – the entire binary system is usually the size of the Earth-Moon system – with an orbital period of 1 to 10 hours.

What is dependent variable of HR diagram?

Absolute Magnitude. The amount of light a star releases. Responding (dependent) variable of the HR diagram. Also called luminosity.

What two variables does the HR diagram compare?

The Hertzsprung–Russell diagram, abbreviated as H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

What is the independent variable for the HR diagram?