Once they had this information, academics were able to calculate the distance to tens of thousands of stars.īut although it was a major breakthrough in star measurement, arguments raged over whether Hipparcos' data contained systematic errors.
HIPPARCOS ASTROMETRY RECOMPUTED LEUWEN FREE
The Hipparcos satellite was launched into space to a point where, free of the Earth's atmosphere (which can blur the effect) it was able to provide a clear set of parallax measurements. In the same way that the finger appears to change position against the background, so stars appear to change their position when viewed from different points on the earth's orbital path. Parallaxes are the same phenomenon we see when we hold a finger in front of our face and view it first with one eye, then the other. The distances were calculated by measuring parallaxes - tiny shifts in the apparent position of stars against a further-flung background. With its help, astronomers were able to recalculate both the date of the Big Bang, and the point at which the very first stars were formed. The original star catalogue was published in 1997 following the European Space Agency's Hipparcos satellite mission, and was described by some as a "quiet revolution" in the study of space. One way or another, everything else astronomers study depends on it." This catalogue marks a huge improvement to the foundations on which we build the entire discipline. "Without reliable distances, everything else is unreliable.
"Knowing the distances of stars is fundamental to everything in astronomy," Dr van Leeuwen explained. Getting the first step as correct as possible is vital for the rest of astronomy, with implications for the scale of the Universe itself. Similarly, the distances to the stars are the first stepping stone in the process of inferring the distance to ever-more remote galaxies and quasars. Without an accurate measurement of distance, the star's true luminosity or size cannot be known. Astronomers can only determine the physical properties of stars by comparing their luminosity with their distance from the earth. Without that type of information, it would be much more difficult to compare the properties of stars or galaxies.
In some cases, its contents are up to five times more accurate than the previous guide, offering scholars what in astronomical terms is the closest they can get to pinpoint accuracy. The book has been compiled almost single-handedly by Dr Floor van Leeuwen at the University's Institute of Astronomy. Today, scientists will be better able than ever to answer the age-old question, with the release of the most accurate guide to the distances between us and the heavens' far-flung diamonds.Ī new catalogue of stars, the result of a decade's painstaking research at Cambridge University, is being published, giving the distances to almost 118,000 stellar bodies.įor astronomers, "Hipparcos - The New Reduction of the Raw Data" promises to open up a new chapter in the study of the age, size and properties of stars, helping them to tackle fundamental questions about the origins of the universe with greater precision than before. A New Cambridge University star catalogue is the “most accurate ever”.įor thousands of years, people all over the world have gazed at the night sky and wondered just how far they would have to travel to reach the stars.
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