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| Supernova in Galaxy M82, 12 million light years distant. The closest supernova to us in 28 years. |
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Showing posts with label Supernova. Show all posts
Showing posts with label Supernova. Show all posts
Friday, January 24, 2014
Saw the Supernova in M82 Last Night!
Although there were thin, high cirrus clouds in the sky last night, we went out to try to see the supernova in M82. And there it was! Dim, visible only with averted vision, but a distinct bright dot towards the edge of the galaxy: an old star that blew itself to smithereens 12 million years ago, but just now visible due to the finite speed of light. I was using my 5" (130mm) APO refractor and had a hard time seeing it, but that was probably just due to the cirrus cloud cover. This supernova will continue to be visible for the next coupld of weeks and is still brightening!
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Thursday, January 23, 2014
New Supernova Erupts in Galaxy M82
A new supernova has erupted in M82, a nearby galaxy just 12 million light years away. The supernova has already reached magnitude 11.0, bright enough to be seen in small backyard telescopes. This is a Type 1a supernova which occurs when an old, super-dense white dwarf star pulls gas from a nearby companion star. When the mass of the white dwarf reaches 1.4x the mass of our sun the star blows itself to smithereens in a spectacular nuclear fusion event that releases more light and energy than over 400 billion stars. This is one bad explosion you don't want to be anywhere near. Fortunately, at a distance of 12 million light years we are safe.
This is one of the few times that such a bright supernova is easily seen in the northern hemisphere's night sky. It is the closest supernova to us in years. Supernovas are usually spotted in far distant galaxies, hundreds of millions or even billions of light years away, making them difficult to see without huge telescopes. This one in M82, just 12 million light years away, should be easy to see in backyard telescopes.
M82 is well positioned all night long after about 8:00 PM. You can find it along the line that diagonally connects the two bowl stars of the Big Dipper, Phecda and Dubhe.
I do not know if the supernova is visible in binoculars. I will try to check tonight. But it should easily be visible in small telescopes. M82 is well placed all night long since the Big Dipper will be rising in the eastern sky shortly after sunset.
Supernovas are nature's most powerful explosions. The bright dot you see above is just a single star, 12 million light years away, that has blown itself to smithereens in its old age. We should only die so gracefully. Try searching for it tonight. It is a rare wonder to behold such massive power at work in the universe.
This is one of the few times that such a bright supernova is easily seen in the northern hemisphere's night sky. It is the closest supernova to us in years. Supernovas are usually spotted in far distant galaxies, hundreds of millions or even billions of light years away, making them difficult to see without huge telescopes. This one in M82, just 12 million light years away, should be easy to see in backyard telescopes.
M82 is well positioned all night long after about 8:00 PM. You can find it along the line that diagonally connects the two bowl stars of the Big Dipper, Phecda and Dubhe.
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| Find M82 by running a diagonal line from Phecda to Dubhe in the bowl of the Big Dipper. Then extend that line an equal distance into the sky along the diagonal. That's where M82 is. |
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| This is an annimation of M82 before and after the appearance of the Supernova. |
Supernovas are nature's most powerful explosions. The bright dot you see above is just a single star, 12 million light years away, that has blown itself to smithereens in its old age. We should only die so gracefully. Try searching for it tonight. It is a rare wonder to behold such massive power at work in the universe.
Thursday, January 27, 2011
Is the Earth Destined to Have Two Suns?
In one of those displays of National Enquirerdom that seems to strike all too often on the Internet, the Huffington Post wrote an article that received alot of play about the star Betelgeuse going supernova and becoming a second sun in our day time sky. After I explained the bad science behind this "popularization" to an Astronomy Israel tour group from Birthright Israel, one of the students rightly concluded, "So you will have to pick up your children from daycare tomorrow."
Betelgeuse is my favorite star in my favorite constellation, Orion. It is (sometimes) the brightest star in the constellation (it is a variable brightness star), the eighth brightest star in the sky, and one of the most massive and largest stars known. It is one of the few stars whose nature is revealed to the naked eye since it is obviously red. Well, it is "obviously" red only after I point out to our guests that stars actually have naked-eye color and I ask them what color they think Betelgeuse is. Everyone is astonished to realize that Betelgeuse is red, although the women seem to see this more quickly than the men. I then like to do a color comparison with Rigel, the young, hot, white-blue star in Orion's knee.
Betelgeuse is what astronomers know as a red supergiant star, a massive star that is nearing the end of its life, has burnt most of its hydrogen and helium fuel in thermonuclear reactions that power it and has cooled, thereby glowing red, a condition visible to the naked eye. A star in this condition is ready to go supernova, that is blow itself to bits in one of the most massive explosions in the universe. A supernova can generate more energy and become brighter than the whole galaxy of stars that contain it, such is the power of a supernova explosion. This, apparently, was the excitement behind the Huffington Post article.
Of course, this has been know for years to astronomers, plus when we realize that "nearing the end of its life" in cosmological terms means "could happen in the next million years", there is no reason to think you will not have to pick your children up from daycare tomorrow. Indeed, even if Betelgeuse were to go supernova tomorrow (or 600 years ago, which it would have to do to go supernova tomorrow, since it is 600 light years distant) it is so far away, that it would be no brighter than the full moon in our daytime sky, and still just a point of light to our naked eye. Bright, yes, but not exactly a second sun. This could last for anywhere from a few days to a few months as the dying star collapsed to a neutron star core.
One of the more amazing things about Betelgeuse is that it is so huge that it was the first star whose stellar disk was resolved by telescopes on earth, the first such stellar disk besides our sun's ever seen. This was done using a technique called speckle interferometry in which the output of two telescopes separated by some distance is combined to create a single image of a star. In 1995 the Hubble Space Telescope was the first single telescope to reveal the disk of the star. Recently, using the Infrared Optical Telescope Array (IOTA), the disk of Betelgeuse was resolved using interferometry to reveal two hot spots.
Betelgeuse is so large that if it were in the place of our sun, its radius would extend to engulf the planet Jupiter, or much of our entire solar system.
But you're still going to have to pick up your kids from day care tomorrow. And probably for at least a few 100,000 years beyond that. Maybe even a million.
Keep on looking up!
Betelgeuse is my favorite star in my favorite constellation, Orion. It is (sometimes) the brightest star in the constellation (it is a variable brightness star), the eighth brightest star in the sky, and one of the most massive and largest stars known. It is one of the few stars whose nature is revealed to the naked eye since it is obviously red. Well, it is "obviously" red only after I point out to our guests that stars actually have naked-eye color and I ask them what color they think Betelgeuse is. Everyone is astonished to realize that Betelgeuse is red, although the women seem to see this more quickly than the men. I then like to do a color comparison with Rigel, the young, hot, white-blue star in Orion's knee.
Betelgeuse and Rigel, the two brightest stars in the constellation Orion. Betelgeuse is an aging red supergiant. Rigel is a bright, young, hot blue-white star. Their natures are revealed even to the naked eye. (Click for full size)
Betelgeuse is what astronomers know as a red supergiant star, a massive star that is nearing the end of its life, has burnt most of its hydrogen and helium fuel in thermonuclear reactions that power it and has cooled, thereby glowing red, a condition visible to the naked eye. A star in this condition is ready to go supernova, that is blow itself to bits in one of the most massive explosions in the universe. A supernova can generate more energy and become brighter than the whole galaxy of stars that contain it, such is the power of a supernova explosion. This, apparently, was the excitement behind the Huffington Post article.
Of course, this has been know for years to astronomers, plus when we realize that "nearing the end of its life" in cosmological terms means "could happen in the next million years", there is no reason to think you will not have to pick your children up from daycare tomorrow. Indeed, even if Betelgeuse were to go supernova tomorrow (or 600 years ago, which it would have to do to go supernova tomorrow, since it is 600 light years distant) it is so far away, that it would be no brighter than the full moon in our daytime sky, and still just a point of light to our naked eye. Bright, yes, but not exactly a second sun. This could last for anywhere from a few days to a few months as the dying star collapsed to a neutron star core.
Betelgeuse, as imaged by the Hubble Telescope in 1995, would extend beyond the orbit of Jupiter if in place of our sun, consuming 75% of our solar system.
One of the more amazing things about Betelgeuse is that it is so huge that it was the first star whose stellar disk was resolved by telescopes on earth, the first such stellar disk besides our sun's ever seen. This was done using a technique called speckle interferometry in which the output of two telescopes separated by some distance is combined to create a single image of a star. In 1995 the Hubble Space Telescope was the first single telescope to reveal the disk of the star. Recently, using the Infrared Optical Telescope Array (IOTA), the disk of Betelgeuse was resolved using interferometry to reveal two hot spots.
Two hot spots are imaged on the star Betelgeuse by the IOTA.
Betelgeuse is so large that if it were in the place of our sun, its radius would extend to engulf the planet Jupiter, or much of our entire solar system.
But you're still going to have to pick up your kids from day care tomorrow. And probably for at least a few 100,000 years beyond that. Maybe even a million.
Keep on looking up!
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