Looking Directly at Extrasolar Planets 92
D2Deek writes "Science Daily is reporting on a new device called an Optical Vortex Coronagraph that's been invented to directly image planets orbiting other stars by using a special lens that "spins out" the light from the star leaving only the reflected light from the planet." I just can't imagine trying to clean a lens shaped like a giant corkscrew.
The light of a planet (Score:2, Insightful)
I thought a planet must be illuminated by light from a star, and not emitting light itself?
Anyway, this technology might be useful for photography, so that one will never get an overexposed shot again.
Re:The light of a planet (Score:3, Informative)
I thought a planet must be illuminated by light from a star, and not emitting light itself?
What this is referring to is the light directly from the star outshining the planet's reflected light.
I would assume, at anyrate. I am still trying to load the article.
Re:The light of a planet (Score:1)
Re:The light of a planet (Score:4, Informative)
(Actually, I don't know if the proportions are even remotely close, but meh.)
Re:The light of a planet (Score:4, Insightful)
The point is, the analogy does get across the difficulty of this acheivement quite well, even moreso when you don't knitpick it to oblivion.
Re:The light of a planet (Score:1, Offtopic)
Advanced species (Score:1)
Re:The light of a planet (Score:1)
Uh... from the article summary:
"...using a special lens that "spins out" the light from the star leaving only the reflected light from the planet."
Re:The light of a planet (Score:4, Informative)
Re:The light of a planet (Score:2)
Re:The light of a planet (Score:2, Informative)
Re:The light of a planet (Score:3, Informative)
15years*300000km/s*86400s*364.25days = 14162040000000km, not 472068000km
Thus, the angle comes to 5.63e-7 degrees, or 0.002 arcseconds
Re:The light of a planet (Score:2)
That would explain why my answer was so big, eh.
Re:The light of a planet (Score:5, Informative)
Re:The light of a planet (Score:3, Informative)
I think you dropped a 300,000 km/s.
15 years
Re:The light of a planet (Score:2)
"I think you dropped a 300,000 km/s."
Hadn't you heard? The Galactic Senate, in an effort to save our endangered antimatter reserves, lowered the speed of light to 1 km/s in order to conserve energy. Phhzzggzztyt Abbmmmun, the senior senator from Hierantos VIII, said "Someone needs to think of the larvae."
Of course, it wasn't unanimous. L'fhong Di Tabax, representing the Chorabax Cluster suggested that it was "The Andromeda energy cartel's fault" and added that "if they don't shape up, we should bom
Re:The light of a planet (Score:2, Informative)
On a side note, Eps Eri C (the smaller planet) seems to orbit about 28 au from its parent star - I would think this would be a perfect candidate for this technology! (I'm too lazy to work out t
Re:The light of a planet (Score:5, Informative)
Re:Newbie buts in (Score:2)
Re:The light of a planet (Score:2)
It can reflect light from stars.
Re:The light of a planet (Score:1)
If you want to get really technical, planets emit light too, they just do it in really really small amounts, and in the infrared...
Erm... not so sure on the overexposure bit. (Score:1)
Re:The light of a planet (Score:1)
Re:The light of a planet (Score:1)
Do not... (Score:5, Funny)
Re:Do not... (Score:1)
That was my first thought when I read the headline. I guess
Optical Vortex Coronagraph (Score:5, Funny)
Re:Optical Vortex Coronagraph (Score:2, Funny)
lens-cleaning (Score:2, Funny)
Real Genius (Score:2)
Kent: My condolences on your meltdown.
Chris Knight: What meltdown, Kent?
Kent: I'm not saying you had one, because how would I know? But just in case you do.
Chris Knight: You slime!
Kent: It's your own fault, Knight. Didn't anyone tell you to make sure your optics are clean?
Actual Press Release text (Score:4, Informative)
A new optical device might allow astronomers to view extrasolar planets directly without the annoying glare of the parent star. It would do this by "nulling" out the light of the parent star by exploiting its wave nature, leaving the reflected light from the nearby planet to be observed in space-based detectors.
About ten years ago, the presence of planets around stars other than our sun was first deduced by the very tiny wobble in the star's spectrum of light imposed by the mutual tug between the star and its satellite. Since then, more than 100 extrasolar planets have been detected in this way. Also, in a few cases the slight diminution in the star's radiation caused by the transit of the planet across in front of the star has been observed. Many astronomers would, however, like to view the planet directly, a difficult thing to do.
Seeing the planet next to its bright star has been compared to trying to discern, from a hundred meters away, the light of a match held up next to the glare of an automobile's headlight. The approach taken by Grover Swartzlander and his colleagues at the University of Arizona is to eliminate the star's light by sending it through a special helical-shaped mask, a sort of lens whose geometry resembles that of a spiral staircase turned on its side.
The process works in the following way: light passing through the thicker and central part of the mask is slowed down. Because of the graduated shape of the glass, an "optical vortex" is created: the light coming along the axis of the mask is, in effect, spun out of the image. It is nulled, as if an opaque mask had been placed across the image of the star, but leaving the light from the nearby planet unaffected.
The idea of an optical vortex has been around for many years, but it has never been applied to astronomy before. In lab trials of the optical vortex mask, light from mock stars has been reduced by factors of 100 to 1000, while light from a nearby "planet" was unaffected (see figure).
Attaching their device to a telescope on Mt. Lemon outside Tucson, Arizona, the researchers took pictures of Saturn and its nearby rings to demonstrate the ease of integrating the mask into telescopic imaging system. This is, according to Swartzlander (520-626-3723, grovers@optics.arizona.edu), a more practical technique than merely attempting to cover the star's image, as is done in coronagraphs, devices for observing our sun's corona by masking out the disk of the sun. It could fully come into its own on a project like the Terrestrial Planet Finder, or TPF, a proposed orbiting telescope to be developed over the coming decade and designed to image exoplanets.
Foo et al., Optics Letters, 15 December 2005 Summary of articles related to optical vortex on Swartzlander's Web page
Someone more patient than I can put in the links to the figures. See http://aip.org/pnu/2005/755.html [aip.org] for everything.
Here's additional linkage (Score:3, Informative)
Optical Vortex Coronagraph Figures
Optics Letters Preprint (4.8 Mb) [nyud.net][pdf] --- To Appear 15 December (ol.osa.org)
This work first appeared in the Master Degree Thesis of Greg Foo:
OSC QC350.O77 Vol. 353, 2005.
I have a concern, or at least a question... (Score:2)
cleaning (Score:5, Funny)
Just run a lint-free Debian logo through it a couple of times.
Strip coating (Score:5, Interesting)
Beatles to Light Vortex Guys (Score:1)
Replacing coronography (Score:2, Interesting)
I wonder if it could be applied to observing galaxies too... I mean, I'd be curious to know what other uses could be found to this technique
Re:Replacing coronography (Score:4, Informative)
"These calculations assume no aberrations or other scattering sources, and they assume the vortex mask can be made achromatic."
http://www.u.arizona.edu/~grovers/ovc.html [arizona.edu]
In other words, the lens material is made from unobtanium and the rest of the system has to be perfect. The author certainly knows this will never happen.
Mike
Re: (Score:2, Informative)
That's... (Score:4, Funny)
Re:That's... (Score:1)
Rocket scientists being the best people to clean corkcrew shaped lenses, of course...
Re:That's... (Score:1)
Yep, it works like this;
Foo et al. (Score:5, Funny)
(The full paper title is "Optical Vortex Coronagraph" by Gregory Foo, David M. Palacios, Grover A. Swartzlander Jr., College of Optical Sciences, University of Arizona).
Re:Foo et al. (Score:5, Funny)
Re:Foo et al. (Score:1, Interesting)
Re:Foo et al. (Score:3, Funny)
Re:Foo et al. (Score:2)
Re:Foo et al. (Score:2, Funny)
Re:Foo et al. (Score:1)
One can always dream about the possibilities though...
logically speaking... (Score:1)
Elementary, my dear Watson!
Azathoth have mercy (Score:4, Funny)
"As Gilman looked into the Optical Vortex Coronagraph at the extrasolar planet, he became conscious of some formless alien presence watching him with horrible intentness. He felt entangled with something -- something which was not in the telescope, but which had looked through it at him. Something which would ceaselessly follow him.
"Cautious investigators will hesitate to challenge the common belief that Gilman was killed by lightning, or by some profound nervous shock derived from an electrical discharge. Archaeologists and astronomers, however, are still trying to explain the bizarre designs impressed on the special helical-shaped mask, whose inner side bore ominous stains."
Re:Azathoth have mercy (Score:1)
you need to seek for the tall black man, and the bizzare flute songs near the telescope main char
Re:Azathoth have mercy (Score:2)
Re:Azathoth have mercy (Score:1)
Re:Azathoth have mercy (Score:1)
The point (Score:5, Insightful)
Re:The point (Score:3, Informative)
And you know this because you have witnessed the entirety of nature? Or this has been deduced and isn't actually a fact, but an assumption?
Actually, O2 does appear in places other than our planet (places assumed to be devoid of life), just not in abundance. But even an abundance is only a hint that life exists. There are inorganic processes that can create oxygen. These usually don't create abundant amounts, but we'v
Re:The point (Score:2, Informative)
Indeed. The real catch is, oxygen tends to get consumed by other common geological and chemical processes. If all life on Earth died today, oxygen would become a trace element in the Earth's atmosphere within a few thousand years (i.e. practically instantaneously on a geological timescale). Whatever process was generating atmospheric O2 would have to be doing it currently and continuously and on a massive scale. Although alternatives are not impossible, so far, there is
Re:The point (Score:1)
What a pissy, arrogant thing to say. What are you, 12 years old?
I can imagine what it must be like for a teacher to have you as one of his students.
teacher: "All life evolved from simpler life forms."
pedrito: "AND U KNOW THIS B/C U PERSONALY WITNES IT??? NO! I THINK NOT!!!!111"
lol. get over yourself dude. What I said was a fact. This telescope isn't going to produce the kind of image that hubble does. Nobody is going to have a pictur
Re:Far too many assumptions (Score:2)
He doesn't say that at all. An implication is not necessarily an equivalence, or proposed to be one.
The problem... (Score:1)
Re:The problem... (Score:3, Insightful)
Re:The problem... (Score:2)
Extra-solar planets? (Score:2, Interesting)
I'm not saying it's unimportant to continue with research like this, only that I wish more effort were put into slightly less glamorous subjects like Pluto that could actually do us some tangible good one da
Re:Extra-solar planets? (Score:2, Informative)
Can this be done without vortex lens? (Score:3, Insightful)
100-to-1000 looks like a very poor efficiency (Score:2, Interesting)
Compared to this, the damping factor announced in the original paper (between 100 and 1000), would loo
Re:100-to-1000 looks like a very poor efficiency (Score:1, Funny)
Cheers,
Ben
Re:100-to-1000 looks like a very poor efficiency (Score:1)
in fact it means you'll shift half of the star light out of phase, so that instead of having "constructive interferometry" (ie, a dot of light at the center of the interferogram), the light from one of the arms of the interferometer cancels the other's.
This is supposed to happen *just* at the place of the star, and not at the planet location, which means the accuracy of this "cancelling" device must be indeed very great...
Hervé
marketing spin (Score:2)