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Most stars are of almost constant luminosity. Our own Sun is a good example of one which goes through relatively little variation in brightness (usually about 0.1% over an 11 year solar cycle). Many stars, however, undergo significant variations in luminosity, and these are known as variable stars.
Broadly speaking, variable stars are of two types:
- stars that are intrinsically variable, that is, their luminosity actually changes, for example because the star periodically swells and shrinks;
- eclipsing and rotating variables, where the apparent changes in brightness are a perspective effect.
Discovery history
More on [ Variable star ]
Millionaire Follows Dad's Footsteps — Into Space
Thu, 09 Oct 2008 08:41:00 -0400
Richard Garriott, a famous video game developer, is paying millions of dollars for a ride on a Russian rocket to the International Space Station. He has wanted to go to space since he was a kid. His father and all of his neighbors were NASA astronauts. It's the first time the child of an American astronaut will blast off into space.
Young Galaxy's Magnetic Field Is Surprisingly Strong
Fri, 03 Oct 2008 13:53:00 -0400
Current models indicate that the magnetic fields that enclose galaxies grow slowly over billions of years. But scientists have used a telescope to peer back millions of years in time and discovered a distant galaxy with a magnetic field at least 10 times the average strength.
SpaceX Celebrates First Successful Rocket Launch
Fri, 03 Oct 2008 13:53:00 -0400
SpaceX's flagship Falcon1 rocket has successfully launched from an island in the central Pacific, becoming the first privately-developed rocket to orbit the planet. NASA has already contracted SpaceX to begin private space flight missions to the International Space Station beginning in 2010.
Computer Malfunction Delays Hubble Mission
Fri, 03 Oct 2008 13:31:00 -0400
NASA has postponed a planned repair mission to the Hubble Space Telescope after a new problem developed with the orbiting observatory. Ed Weiler, associate administrator of the Science Mission Directorate at NASA, explains why repairs won't take place until Feb. 2009 — at the earliest.
For Young Chinese, Spacewalk An Indicator Of Might
Sat, 27 Sep 2008 17:05:00 -0400
China on Saturday will become only the third nation — after Russia and the United States — to carry out a spacewalk. The event will be broadcast live nationwide. This milestone underscores China's technological achievements and is boosting national pride.
Solar Winds, Crucial To Life On Earth, Decreasing
Fri, 26 Sep 2008 12:45:00 -0400
Solar winds — invisible gas plasma emitted by the Sun — protect the solar system from cosmic rays that are hostile to terrestrial life. But new data from the Ulysses NASA probe indicate solar wind output is lower than has ever been previously documented.
A Ritzian Interpretation of Variable Stars - A study on the nature of the speed of light in space using light curves and spectroscopic observations of variable stars as evidence.
Meta Description: [ Research into the nature of
the speed of light in space using observations of variable stars as
evidence ]
American Association of Variable Star Observers - The largest organization for variable stars: provides professional and amateur collaboration, research, and analysis of variable star observations.
Meta Description: [ The American Association of Variable Star Observers: Professional and Amateur
collection,
research, and analyses of variable star observations. ]
Astronomical Society of South Australia - ASSA's variable star group. News, FAQ, charts, and software.
Meta Description: [ Watch a variable for a change! ]
Astronomy On-Line - Collaborative Project aimed at getting new people involved in variable star observing.
Meta Description: [ ESO is the European Organisation for
Astronomical Research in the Southern Hemisphere. It operates the La Silla
Paranal Observatory in Chile and has its headquarters in Garching, near
Munich, Germany. ]
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Brigham Young University Variable Star Database - Currently contains 311 stars which have been classified as Delta Scutis or Gamma Doradus in some published source.
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Free Virtual Galaxy Project - By Jim Smith's. Purpose is to provide a zero cost, interactive 3D virtual reality system.
General Catalog of Variable Stars Research Group - Research group working on the GCVS, Sternberg Astronomical Institute, Moscow, Russia. Includes catalogs and publications.
Information Bulletin on Variable Stars - The IBVS is a bulletin of Commissions 27 and 42 of the International Astronomical Union, published by Konkoly Observatory, Budapest, Hungary.
Skyandtelescope.com - Variable Stars - Observing variable stars.
Meta Description: [ Sky & Telescope, the Essential Magazine of Astronomy. News, observing tips, how-to advice, and more! ]
The Cepheid Distance Scale: A History - A critical review of the Cepheid distance scale, from its inception, to the Hipparcos mission and beyond.
Meta Description: [ A critical review of the Cepheid distance scale, from its inception to the Hipparcos mission and beyond ]
The Minima of Algol - An article by Alan MacRobert from Sky and Telescope Magazine about the star Algol (Beta Persei) was the first eclipsing variable star ever discovered.
Meta Description: [ Now you can calculate the dates and times (local and Universal Times) when the eclipsing variable star Algol should be at its dimmest (magnitude 3.4 instead of its usual 2.1).
]
The Top Twelve Naked-Eye Variable Stars - An article by John Isles from Sky and Telescope Magazine.
Meta Description: [ Lurking in the seemingly changeless constellations are a few inconstant stars that pulse and eclipse. Here are a dozen variables that are easy to observe. ]
| Variable stars are stars that change brightness. The brightness changes of these stars can range from a thousandth of a ... | |
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