Twin stars observed in the Orion Nebula, a stellar nursery 1,500 light years from Earth. At this distance the twin stars appear as a single point of light. The observations were made with the NSF-supported SMARTS telescopes at the Cerro Tololo Inter-American Observatory in Chile, and with access provided by NSF to the Hobby-Eberly Telescope at the MacDonald Observatory in Texas.
Click on image for full size
Image Courtesy of NASA-JPL/HST and David James (Vanderbilt)
Newly Born Twin Stars are Far From Identical
News story originally written on June 18, 2008
Two stars, each with the same mass and in orbit around each other, are twins that one would expect to be identical. So astronomers were surprised when they discovered that twin stars in the Orion Nebula, a well-known stellar nursery 1,500 light years away, were not identical at all. In fact, these stars exhibited significant differences in brightness, surface temperature and possibly even size.
The study, which is published in the June 19 issue of the journal Nature, suggests that one of the stars formed significantly earlier than its twin. Because astrophysicists have assumed that binary stars form simultaneously, the discovery provides an important new challenge for today's star formation theories, forcing theorists to reexamine their models to see if the models can indeed produce binaries with stars that form at different times.
Because mass and age estimates for stars less than a few million years old are based on models that were calibrated with measurements of binary stars presumed to have formed simultaneously, this new discovery may cause astronomers to readjust their estimates for thousands of young stars.
The newly formed twin stars are about 1 million years old. With a full lifespan of about 50 billion years, that makes them equivalent to one-day-old human babies.
"The easiest way to explain the observed differences is if one star was fully formed about 500,000 years before its twin. That would be equivalent to a human birth-order difference of about half a day," said Keivan Stassun, associate professor of astronomy at Vanderbilt University.
Stassun and Robert D. Mathieu from the University of Wisconsin-Madison headed up the project, with significant funding from the National Science Foundation.
Text above is courtesy of the National Science Foundation
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, ranging from seismology
, rocks and minerals
, and Earth system science
You might also be interested in:
Would it be more difficult to pull an elephant or a mouse? If you pulled each animal with the same amount of force, the elephant would respond less to pulling, even if he didnít pull back at all. Thatís...more
Astronomers use the term "magnitude" to describe the brightness of an object. The magnitude scale for stars was invented by the ancient Greeks, possibly by Hipparchus around 150 B.C. The Greeks grouped...more
A new study has found that a mixing of two different types of magma is the key to the historic eruptions of Mount Hood, Oregon's tallest mountain, and that eruptions often happen in a relatively short...more
Researchers have found a primitive Earth mantle reservoir on Baffin Island in the Canadian Arctic. Geologist Matthew Jackson and his colleagues from a multi-institution collaboration report the finding--the...more
Some geologic faults that appear strong and stable, slip and slide like weak faults. Now an international team of researchers has laboratory evidence showing why some faults that 'should not' slip are...more
A new analysis of the unusually long solar cycle that ended in 2008 suggests that one reason for the long cycle could be a stretching of the sun's conveyor belt, a current of plasma that circulates between...more
Anyone who has ever cut down a tree is familiar with the rings radiating out from the center of a tree trunk marking the tree's age. Careful study of tree rings can offer much more: a rich record of history...more