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Latest Variable star Stories

42db470519956e7d7d10e9eb2969ec811
2010-11-24 12:50:00

By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory...

a032652b36ab66241b73a3978837b4211
2009-12-16 09:05:45

A team of Chinese astronomers have discovered a giant planet close to the exotic binary star system QS Virginis. Although dormant now, in the future the two stars will one day erupt in a violent nova outburst. Professor Shengbang Qian of Yunnan Observatory leads the team of scientists who report their work in the journal Monthly Notices of the Royal Astronomical Society. QS Virginis lies in the direction of the constellation of Virgo and is about 157 light years from the Sun. The system is...

52b6e04ea486fd86b7744aa05a59e9a71
2009-12-15 09:55:00

About 550 light-years from Earth, a star like our Sun is writhing in its death throes. Chi Cygni has swollen in size to become a red giant star so large that it would swallow every planet out to Mars in our solar system. Moreover, it has begun to pulse dramatically in and out, beating like a giant heart. New close-up photos of the surface of this distant star show its throbbing motions in unprecedented detail. "This work opens a window onto the fate of our Sun five billion years from now,...

ecfc4d40d06e561c7215b3ed6c2a5a1b
2009-12-07 07:30:00

Astronomers facing Socratic "ignorance" An extensive study made with ESO's Very Large Telescope deepens a long-standing mystery in the study of stars similar to the Sun. Unusual year-long variations in the brightness of about one third of all Sun-like stars during the latter stages of their lives still remain unexplained. Over the past few decades, astronomers have offered many possible explanations, but the new, painstaking observations contradict them all and only deepen the mystery. The...

2009-11-05 09:45:27

Cataclysmic variable stars This week, Astronomy & Astrophysics publishes a somewhat unusual research article because it is co-authored by German high-school students. Led by astronomer Klaus Beuermann (University of Göttingen, Germany), the team [1] involves a secondary school physics teacher, three students from two high schools in Göttingen [2], and three professional astronomers. The team made use of a remotely-controlled 1.2-meter telescope in Texas [3], funded by the...

bfee3fc89500505af6b838f397dbfa751
2009-06-08 13:25:00

Ohio State University researchers have found a way to measure distances to objects three times farther away in outer space than previously possible, by extending a common measurement technique.They discovered that a rare type of giant star, often overlooked by astronomers, could make an excellent signpost for distances up to 300 million light years -- and beyond.Along the way, they also learned something new about how these stars evolve.Cepheid variables -- giant stars that pulse in...

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2009-05-07 09:13:00

Whatever dark energy is, explanations for it have less wiggle room following a Hubble Space Telescope observation that has refined the measurement of the universe's present expansion rate to a precision where the error is smaller than five percent. The new value for the expansion rate, known as the Hubble constant, or H0 (after Edwin Hubble who first measured the expansion of the universe nearly a century ago), is 74.2 kilometers per second per megaparsec (error margin of...

1e57127d7cbed58bcd46a2c80eaf3cc11
2008-09-22 08:00:00

Pulsating stars enable a new precise determination of the rotation of our Galaxy New, very precise measurements have shown that the rotation of the Milky Way is simpler than previously thought. A remarkable result from the most successful ESO instrument HARPS, shows that a much debated, apparent 'fall' of neighborhood Cepheid stars towards our Sun stems from an intrinsic property of the Cepheids themselves. The result, obtained by a group of astrophysicists led by Nicolas Nardetto, will soon...

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2008-05-01 12:29:26

Discovery helps solve riddle of where the carbon white dwarfs come from, and what happens to their hydrogen and helium University of Texas at Austin astronomers Michael H. Montgomery and Kurtis A. Williams, along with graduate student Steven DeGennaro, have predicted and confirmed the existence of a new type of variable star, with the help of the 2.1-meter Otto Struve Telescope at McDonald Observatory. The discovery is announced in today's issue of Astrophysical Journal Letters. This research...

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2008-02-11 08:30:00

Astronomers calibrate the distance scale of the Universe Taking advantage of the presence of light echoes, a team of astronomers have used an ESO telescope to measure, at the 1% precision level, the distance of a Cepheid - a class of variable stars that constitutes one of the first steps in the cosmic distance "Our measurements with ESO's New Technology Telescope at La Silla allow us to obtain the most accurate distance to a Cepheid," says Pierre Kervella, lead-author of the paper reporting...


Latest Variable star Reference Libraries

6_f1577ee462b741c03ef6a7d23d2cd6905
2004-10-19 04:45:43

Variable Star -- Most stars are of nearly constant luminosity. Our own Sun is a good example which goes through practically no measurable variation in brightness. There are, however, stars which do vary in brightness, called variable stars. They fall into two main groups: Intrinsic variables These are stars which have intrinsic variations in brightness, that is the star itself gets brighter and dimmer. There are many types of intrinsic variables, the main types being: -- Mira...

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