Variable Stars:
- Variable stars are simply stars
that change brightness, or apparent magnitude,
over a period of time; from seconds to years as
perceived on Earth.
- More than 100,000 variable stars
have been observed and cataloged with many more
still to go.
- One example of a variable star
is our Sun which has an output variance of 0.1%
or 1000th of its magnitude over an 11-year
cycle. (SPACE)
http://www.space.com/15396-variable-stars.html
- Three different types of variable
stars:
- Cepheid Variable : Very luminous,
500-300,000 times greater than the sun with
short periods of change that range from
1-100 days. Valuable to scientists because
of the intrinsic period of dimming and
brightening which forms the basis for
distance measurements. (This type is the
focus of this project.)
- Pulsating Variables : include RR Lyrae
stars, which are older, not as large as
Cepheid stars with short periods and RV
Tauri which are supergiants with longer
periods of large pulsating light.
- Cataclysmic Variables (AKA Explosive
Variables) : Due to thermonuclear processes
either on the surface of inside brighten.
(i.e. supernovae)
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