(PhysOrg.com) -- In 1908, Harvard astronomer Henrietta Swan Leavitt discovered that a class of stars called Cepheids have brightnesses that vary regularly with periods that are directly related to their intrinsic ...
Jan 29, 2010
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(Phys.org) -- The Earth is not at rest. It orbits the Sun, which in turn orbits the center of the Milky Way Galaxy, which in turn moves within the Local Group of Galaxies - a collection of about fifty four ...
Apr 18, 2012
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(Phys.org) —At some stage after its birth in the big bang, the universe began to make galaxies. No one knows exactly when, or how, this occurred. For that matter, astronomers do not know how the lineages ...
Apr 12, 2013
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Of the roughly 420 extra-solar planets now known, about a dozen are in the newly named category of "super-earths," planets whose masses are in between of two and about fifteen earth-masses.
Jan 22, 2010
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Seven years ago, astronomers boggled when they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour. The discovery intrigued theorists, who wondered: If a star can ...
Mar 22, 2012
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A "super-Earth" is a planet around another star (an "exoplanet") whose mass is less than about ten times that of the Earth. Of the 480 or so extrasolar planets now known, most have masses larger than the mass ...
Aug 27, 2010
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(PhysOrg.com) -- Astronomers, in addition to discovering extrasolar planets (about 500 of them currently have known orbital parameters), have detected excess, warm infrared dust emission around many stars.
Sep 24, 2010
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(PhysOrg.com) -- When a treasure hunt comes up empty-handed, the hunters are understandably disappointed. But when astronomers don't find what they are looking for, the defeat can provide as much information as a successful ...
Oct 03, 2008
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How do astronomers weigh a star that's trillions of miles away and way too big to fit on a bathroom scale? In most cases they can't, although they can get a best estimate using computer models of stellar structure.
Oct 15, 2010
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(PhysOrg.com) -- Does a twin Earth exist somewhere in our galaxy? Astronomers are getting closer and closer to finding an Earth-sized planet in an Earth-like orbit. NASA's Kepler spacecraft just launched to ...
Mar 20, 2009
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Beyond the orbit of Neptune reside countless icy rocks known as trans-Neptunian objects (TNOs). One of the biggest, Pluto, is classified as a dwarf planet. The region also supplies us with comets such as famous ...
Sep 13, 2010
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(Phys.org) —In the spring of the year 1006, one thousand and seven years ago this April, observers in China, Egypt, Iraq, Japan, Switzerland (and perhaps North America) reported seeing what might be the ...
Apr 22, 2013
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On Earth, making a map is as easy as taking aerial photographs or surveying a patch of land on foot. In contrast, mapping the Milky Way galaxy is a tremendous challenge. The distances are too large to travel, ...
Jun 03, 2008
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A new image from NASA's Spitzer Space Telescope tells a tale of life and death, and reveals a rich family history. The striking infrared picture shows a colorful cosmic cloud, called W5, studded with multiple ...
Aug 22, 2008
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A thousand years ago, a brilliant beacon of light blazed in the sky, shining brightly enough to be seen even in daytime for almost a month. Native American and Chinese observers recorded the eye-catching event. ...
Oct 06, 2011
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