The Light That Bends!
When a small star like our Sun runs out of hydrogen fuel, its core collapses, and it puffs its outer layers of beautiful varicolored gases into Space, leaving behind a dense little stellar remnant--its former core--called a White Dwarf.
In April 2013, astronomers announced that NASA's highly prolific Kepler Space Telescope, had beamed back evidence of a White Dwarf bending and magnifying the light of its sister star and companion, a still-"living" Red Dwarf.
Kepler was launched on March 6, 2009, aboard a Delta II rocket from Cape Canaveral Air Force Station in Florida.
Kepler's primary mission is to scan for small aberrations that might indicate an extrasolar planet has transited the face ofa Red Dwarf--but sometimes other discoveries are serendipitously made, as well! Serendipity means that you are looking for one thing, but find something else.
This newly observed light bending feat is yet another piece of evidence that Albert Einstein was right about General Relativity, one prediction of which is that light can be bent, or warped, by gravity.
Mass causes a warpage in Spacetime due to its gravity, and this warpage can bend light.
Imagine a trampoline.
Now, imagine a heavy bowling ball thrown onto the center of the trampoline, causing a warpage, or a dimple, in the stretchy fabric.
Now imagine a handful of marbles tossed to where the bowling ball is now dimpling the fabric of the trampoline.
The marbles circle around the bowling ball, and do not travel the straight lines that they normally would, if the bowling ball were not there to warp the fabric of the trampoline.
Now, imagine that the marbles are light, and that this light is being bent around the bowling ball that is warping the fabric of the trampoline.
The trampoline is Spacetime, the bowling ball is a heavy mass--such as that of a star--whose gravity warps the fabric of the trampoline, and the marbles are light emanating from another luminous cosmic object that is being bent as it travels near this warpage.
Almost a century ago, the British astrophysicist Sir Arthur Eddington led a historic expedition to Brazil and to the island of Principe, with the intention of studying solar eclipses.
In this way, Eddington was seeking to test an experimental prediction of Albert Einstein's revolutionary new theory of gravity, the General Theory of Relativity.
Eddington's observations proved to be one in a very long series of tests strongly indicating that Einstein's novel theory is correct.
In 1919, a journalist asked Einstein what his reaction would be if Eddington's observations failed to match the predictions of General Relativity.
Einstein famously answered, with a healthy dose of characteristic self-confidence: "Then I would feel sorry for the good Lord.
The theory is correct.
" Einstein's self-confidence proved to be justified, however, because, over the years, "the theory" has been shown to be correct many times over.
Einstein's first theory of Relativity, his Special Theory of Relativity (1905), describes a Universe that has often been compared to an artist's canvas.
The artist paints lines and points on this wonderful canvas that records all that has ever occurred, is occurring, and will occur.
This painted canvas is the stage where the drama is being played out, rather than the drama itself.
The great achievement uniting the stage with the play came later when, in 1915, Einstein presented his Theory of General Relativity.
Here, Spacetime became one of the major stars in this greatest of all stage plays.
In this universal drama, Spacetime determines how mass moves, and mass determines how Spacetime curves.
Spacetime is as stretchy, as flexible, as the fabric of a trampoline.
The trampoline is just as much of an actor in the play as a bowling ball warping its fabric, or as marbles traveling around the bowling ball.
The drama will continue for as long as the main performers exist.
Light takes a curved path when it has been deflected by a massive object.
This occurs when the heavy mass of an object--such as a star--bends and distorts the light emanating from another luminous object.
The light need not be exclusively visible light--it can be any type of radiation.
As a result of this prediction of General Relativity, light rays are bent away from their normal paths.
The Light That Bends! Red Dwarfs are the smallest main-sequence (hydrogen-burning) stars in the Cosmos, as well as the most numerous.
In fact, the largest Red Dwarfs are only approximately 40% as big as our Sun, and are also considerably cooler.
Because these tiny stars are so small and cool, they can "live"for, perhaps, trillions of years.
This is because their rate of nuclear fusion is comparatively slow.
The bigger the star, the shorter its "life".
Very massive stars are extremely hot; they live fast and die young--generally in the fiery incandescent rage of a supernova explosion.
Because they are so searing-hot, very massive stars have a fast rate of nuclear fusion--and so they burn themselves up very quickly, by star-standards, in a matter of mere millions as opposed to billions of years.
Our Sun, a small star, is almost five billion years old, and will not die for another five billion years.
Red Dwarfs, being cooler and even smaller than our Sun, take their time fusing their precious supply of hydrogen fuel into helium, as well as into an assortment of other heavier elements.
As a star forms from contracting gas within a dense glob within a cold, dark, molecular cloud, the temperature at the heart of this dense glob where the star is forming, soars to such a searing-hot temperature that hydrogen (the lightest atomic element) begins to fuse into helium (the next-lightest element).
This process produces immense quantities of energy, which is the reason why stars shine with their beautiful glittering fires.
Stellar nuclear fusion continues for as long as a "living" star remains on the main-sequence.
The discovery of a White Dwarf bending the light of its companion Red Dwarf, by astronomers using Kepler data, is important because it represents one of the first times this phenomenon has been seen in a binary, or double, star system.
"This White Dwarf is about the size of Earth but has the mass of the Sun.
It's so hefty that the Red Dwarf, though larger in physical size, is circling around the White Dwarf," explained Dr.
Phil Muirhead in an April 4, 2013 NASA Jet Propulsion Laboratory (JPL) Press Release.
Dr.
Muirhead is of the California Institute of Technology (Caltech) in Pasadena, California.
The White Dwarf is bonded to its Red Dwarf star companion in a gravitational dance! Dr.
Muirhead and his team regularly use Kepler data to hunt for and confirm extrasolar planets circling around small Red Dwarfs (M Dwarfs).
When the team first studied Kepler data for a target star dubbed KOI-256, they believed they had spotted an enormous gas-giant extrasolar planet eclipsing the tiny star.
"We saw what appeared to be huge dips in the light from the star, and suspected it was from a giant planet, roughly the size of Jupiter, passing in front," Dr.
Muirhead continued to explain in the April 4, 2013 JPL Press Release.
The team went on to continue their observations of KOI-256 using the Hale Telescope at Palomar Observatory near San Diego, California.
It was then that they discovered that the Red Dwarf was wobbling in a way that was uncharacteristically extreme for the gravitational tug of a mere planet.
They then concluded that a massive White Dwarf was passing behind the Red Dwarf star.
This was subsequently confirmed by ultraviolet measurements of KOI-256 made by the Galaxy Evolution Explorer (GALEX), launched in April 2003.
After the team of astronomers again went back to study the Kepler data, they discovered that when the White Dwarf traveled in front of its sister Red Dwarf star, its gravity caused the starlight to bend and brighten--as predicted by General Relativity.
The light that bends in this starry duo is not unique in astronomy.
In fact, one effect of light-bending, termed gravitational lensing, has helped astronomers to study ancient star-birth, dark energy, and dark matter.
In gravitational lensing, the light of a background object is warped around a massive foreground structure, and is thereby magnified.
This natural magnifying lens has served astronomers very well, enabling them to see objects that would otherwise be difficult to observe.
Gravitational lensing has also been used to spot new extrasolar planets and to find so-called free-floating extrasolar planets that wander lost and alone around our Milky Way Galaxy with no star to call their own.
These orphaned free-floaters wereflung unceremoniously out of their original families, around their parent stars, due to gravitational interactions.
"Only Kepler could detect this tiny, tiny effect.
But with this detection, we are witnessing Einstein's Theory of General Relativity at play in a far-flung star-system," commented Dr.
Doug Hudgins to the press on April 4, 2013.
Dr.
Hudgins is Kepler program scientist at NASA Headquarters, in Washington D.
C.
This research is published in the April 20, 2013 issue of The Astrophysical Journal.
In April 2013, astronomers announced that NASA's highly prolific Kepler Space Telescope, had beamed back evidence of a White Dwarf bending and magnifying the light of its sister star and companion, a still-"living" Red Dwarf.
Kepler was launched on March 6, 2009, aboard a Delta II rocket from Cape Canaveral Air Force Station in Florida.
Kepler's primary mission is to scan for small aberrations that might indicate an extrasolar planet has transited the face ofa Red Dwarf--but sometimes other discoveries are serendipitously made, as well! Serendipity means that you are looking for one thing, but find something else.
This newly observed light bending feat is yet another piece of evidence that Albert Einstein was right about General Relativity, one prediction of which is that light can be bent, or warped, by gravity.
Mass causes a warpage in Spacetime due to its gravity, and this warpage can bend light.
Imagine a trampoline.
Now, imagine a heavy bowling ball thrown onto the center of the trampoline, causing a warpage, or a dimple, in the stretchy fabric.
Now imagine a handful of marbles tossed to where the bowling ball is now dimpling the fabric of the trampoline.
The marbles circle around the bowling ball, and do not travel the straight lines that they normally would, if the bowling ball were not there to warp the fabric of the trampoline.
Now, imagine that the marbles are light, and that this light is being bent around the bowling ball that is warping the fabric of the trampoline.
The trampoline is Spacetime, the bowling ball is a heavy mass--such as that of a star--whose gravity warps the fabric of the trampoline, and the marbles are light emanating from another luminous cosmic object that is being bent as it travels near this warpage.
Almost a century ago, the British astrophysicist Sir Arthur Eddington led a historic expedition to Brazil and to the island of Principe, with the intention of studying solar eclipses.
In this way, Eddington was seeking to test an experimental prediction of Albert Einstein's revolutionary new theory of gravity, the General Theory of Relativity.
Eddington's observations proved to be one in a very long series of tests strongly indicating that Einstein's novel theory is correct.
In 1919, a journalist asked Einstein what his reaction would be if Eddington's observations failed to match the predictions of General Relativity.
Einstein famously answered, with a healthy dose of characteristic self-confidence: "Then I would feel sorry for the good Lord.
The theory is correct.
" Einstein's self-confidence proved to be justified, however, because, over the years, "the theory" has been shown to be correct many times over.
Einstein's first theory of Relativity, his Special Theory of Relativity (1905), describes a Universe that has often been compared to an artist's canvas.
The artist paints lines and points on this wonderful canvas that records all that has ever occurred, is occurring, and will occur.
This painted canvas is the stage where the drama is being played out, rather than the drama itself.
The great achievement uniting the stage with the play came later when, in 1915, Einstein presented his Theory of General Relativity.
Here, Spacetime became one of the major stars in this greatest of all stage plays.
In this universal drama, Spacetime determines how mass moves, and mass determines how Spacetime curves.
Spacetime is as stretchy, as flexible, as the fabric of a trampoline.
The trampoline is just as much of an actor in the play as a bowling ball warping its fabric, or as marbles traveling around the bowling ball.
The drama will continue for as long as the main performers exist.
Light takes a curved path when it has been deflected by a massive object.
This occurs when the heavy mass of an object--such as a star--bends and distorts the light emanating from another luminous object.
The light need not be exclusively visible light--it can be any type of radiation.
As a result of this prediction of General Relativity, light rays are bent away from their normal paths.
The Light That Bends! Red Dwarfs are the smallest main-sequence (hydrogen-burning) stars in the Cosmos, as well as the most numerous.
In fact, the largest Red Dwarfs are only approximately 40% as big as our Sun, and are also considerably cooler.
Because these tiny stars are so small and cool, they can "live"for, perhaps, trillions of years.
This is because their rate of nuclear fusion is comparatively slow.
The bigger the star, the shorter its "life".
Very massive stars are extremely hot; they live fast and die young--generally in the fiery incandescent rage of a supernova explosion.
Because they are so searing-hot, very massive stars have a fast rate of nuclear fusion--and so they burn themselves up very quickly, by star-standards, in a matter of mere millions as opposed to billions of years.
Our Sun, a small star, is almost five billion years old, and will not die for another five billion years.
Red Dwarfs, being cooler and even smaller than our Sun, take their time fusing their precious supply of hydrogen fuel into helium, as well as into an assortment of other heavier elements.
As a star forms from contracting gas within a dense glob within a cold, dark, molecular cloud, the temperature at the heart of this dense glob where the star is forming, soars to such a searing-hot temperature that hydrogen (the lightest atomic element) begins to fuse into helium (the next-lightest element).
This process produces immense quantities of energy, which is the reason why stars shine with their beautiful glittering fires.
Stellar nuclear fusion continues for as long as a "living" star remains on the main-sequence.
The discovery of a White Dwarf bending the light of its companion Red Dwarf, by astronomers using Kepler data, is important because it represents one of the first times this phenomenon has been seen in a binary, or double, star system.
"This White Dwarf is about the size of Earth but has the mass of the Sun.
It's so hefty that the Red Dwarf, though larger in physical size, is circling around the White Dwarf," explained Dr.
Phil Muirhead in an April 4, 2013 NASA Jet Propulsion Laboratory (JPL) Press Release.
Dr.
Muirhead is of the California Institute of Technology (Caltech) in Pasadena, California.
The White Dwarf is bonded to its Red Dwarf star companion in a gravitational dance! Dr.
Muirhead and his team regularly use Kepler data to hunt for and confirm extrasolar planets circling around small Red Dwarfs (M Dwarfs).
When the team first studied Kepler data for a target star dubbed KOI-256, they believed they had spotted an enormous gas-giant extrasolar planet eclipsing the tiny star.
"We saw what appeared to be huge dips in the light from the star, and suspected it was from a giant planet, roughly the size of Jupiter, passing in front," Dr.
Muirhead continued to explain in the April 4, 2013 JPL Press Release.
The team went on to continue their observations of KOI-256 using the Hale Telescope at Palomar Observatory near San Diego, California.
It was then that they discovered that the Red Dwarf was wobbling in a way that was uncharacteristically extreme for the gravitational tug of a mere planet.
They then concluded that a massive White Dwarf was passing behind the Red Dwarf star.
This was subsequently confirmed by ultraviolet measurements of KOI-256 made by the Galaxy Evolution Explorer (GALEX), launched in April 2003.
After the team of astronomers again went back to study the Kepler data, they discovered that when the White Dwarf traveled in front of its sister Red Dwarf star, its gravity caused the starlight to bend and brighten--as predicted by General Relativity.
The light that bends in this starry duo is not unique in astronomy.
In fact, one effect of light-bending, termed gravitational lensing, has helped astronomers to study ancient star-birth, dark energy, and dark matter.
In gravitational lensing, the light of a background object is warped around a massive foreground structure, and is thereby magnified.
This natural magnifying lens has served astronomers very well, enabling them to see objects that would otherwise be difficult to observe.
Gravitational lensing has also been used to spot new extrasolar planets and to find so-called free-floating extrasolar planets that wander lost and alone around our Milky Way Galaxy with no star to call their own.
These orphaned free-floaters wereflung unceremoniously out of their original families, around their parent stars, due to gravitational interactions.
"Only Kepler could detect this tiny, tiny effect.
But with this detection, we are witnessing Einstein's Theory of General Relativity at play in a far-flung star-system," commented Dr.
Doug Hudgins to the press on April 4, 2013.
Dr.
Hudgins is Kepler program scientist at NASA Headquarters, in Washington D.
C.
This research is published in the April 20, 2013 issue of The Astrophysical Journal.
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