Showing posts with label telescope. Show all posts
Showing posts with label telescope. Show all posts

Saturday, March 22, 2008

Hubble Discovers Life Basics On Distant Sphere

A NASA developed rendering of HD 189733b, an extrasolar planet, is located more than 60 light years from Earth, which has the organic molecule methane in its atmosphere. Image Credit: NASA, ESA, and G. Bacon (STScI)

Hubble Discovers Life Basics On Distant Sphere

The upgraded Hubble telescope, with its perch circling above the Oblate Spheroid out in space, has discovered what is considered the basic evidence of the “signature” that life (as we understand it) could exist on another planet. The distant sphere is located 63 million light years away and is known as HD 189733b.

The process of the creation of life requires the existence of carbon based gasses and other chemicals on which bacteria and other life forms are composed. It is believed that without these signature compounds, life could and would not develop.

Stellar spectrography by a flame-cutting grid - Capella's Spectrum, order 1 spectral image taken by a Philips vesta webcam. Image Credit: lightfrominfinity.org

So the discovery of such signature evidence through spectrography with instruments on platforms like the Hubble Telescope, on spheres that exist in other solar systems, makes for a better understanding and pushes the envelop of current scientific techniques.

This excerpted from WIRED -

Molecular Basis of Life Discovered on Extrasolar Planet
By Alexis Madrigal, Wired - 03.19.08 6:15 PM

Scientists using the Hubble Space Telescope have for the first time found the telltale signature of methane, an organic molecule, in the atmosphere of a planet outside our solar system.

Methane is one of the chemicals of life, an organic compound in the class of molecules containing carbon. However, no life is likely to exist on the large, gaseous planet known as HD 189733b. Its daily temperatures can reach 1,340 degrees Fahrenheit.

"These measurements are a dress rehearsal for future searches for life," said
Mark Swain, a scientist at NASA's Jet Propulsion Laboratory and the lead author of a new study that appears in Nature tomorrow. "If we were able to detect [methane] on a more hospitable planet in the future, it would really be something exciting."
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Since the discovery of the first so-called exoplanet 13 years ago, scientists have been able to glean little about the 270-plus known extrasolar planets. Even rough sizes and masses have been calculated for a mere 30 of those planets. It is only in the last year that scientists have begun to characterize the conditions on these planets, like their surface temperatures, and as in this case, the chemical composition of their atmosphere. Such findings not only shed light on other solar systems, but also on our own.
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HD 189733b, a so-called "hot Jupiter," located 63 light years away, has proven a boon for scientists studying exoplanets. Its large size and proximity to its star mean that it dims the star's light more than any other known exoplanet. Combine that with its home star's high brightness, and scientists find that the system creates the best viewing conditions of any known extrasolar system.
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At different wavelengths, every atom and molecule has its own telltale footprint, so scientists can convert what are known as absorption spectra into the chemical composition of the object they're looking at.

The technique, known as spectrography, will remain the main scientific technique for learning about exoplanets into the future with planets that could support life.
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"Twenty years from now, we'll be able to do this for superearths," said
Jonathan Fortney, an astronomy professor at the University of California, Santa Cruz. "We'll be able to see methane in the atmosphere of an Earth-like planet."

To do so, however, astronomers will need new tools. Swain's team used Hubble's Near Infrared Camera and Multi-Object Spectrometer to capture rough spectrographic data. They were forced to use the low-resolution tool because the dedicated instrument for spectrography -- the Space Telescope Imaging Spectrograph -- broke in 2003, Redfield said.

"The STIS spectrograph would get resolutions several orders of magnitude higher than the tool they used," said
Seth Redfield, a Hubble postdoctoral fellow at the University of Texas at Austin, who previously identified sodium in HD 189733b's atmosphere.

He said NASA was planning to try to fix the tool in late summer of this year, and that access to the tool could lead to new discoveries. In the meantime, scientists will keep plugging away, revealing the properties of planets dozens of light years away, molecule by molecule.

"We know so little observationally about these planetary atmospheres that any sort of measurement is tremendously exciting," Redfield said.

Reference Here>>

Saturday, October 27, 2007

Dusty Galaxies Yield Up Hundreds Of Black Holes

A long-lost population of active supermassive black holes, or quasars, has been uncovered by NASA's Spitzer and Chandra space telescopes. This image, taken with Spitzer's infrared vision, shows a fraction of these black holes, which are located deep in the bellies of distant, massive galaxies (circled in blue). This image was taken by Spitzer's multiband imaging photometer at a wavelength of 24 microns. It shows the faintest distant objects ever observed with Spitzer at this wavelength. -- Image Credit: NASA/JPL-Caltech/ Commissariat a l'Energie Atomique

Dusty Galaxies Yield Up Hundreds Of Black Holes

Astronomers using specialized NASA telescopes have found hundreds of quasar/black holes hiding deep inside dusty galaxies billions of light-years away.

For decades, astronomers have long suspected that the universe held more quasars/black holes but were unable to discover where to look to find them until recently.

The newfound quasars are helping answer fundamental questions about how massive galaxies evolve. For example, astronomers have learned that most massive galaxies steadily build up their stars and black holes simultaneously until they get too big and their black holes suppress star formation.

The observations also suggest that collisions between galaxies might not play as large a role in galaxy evolution as previously believed, here on this Oblate Spheroid.

A growing black hole, called a quasar, can be seen at the center of a faraway galaxy in this artist's concept. Astronomers using NASA's Spitzer and Chandra space telescopes discovered swarms of similar quasars hiding in dusty galaxies in the distant universe. The Spitzer observations were made as part of the Great Observatories Origins Deep Survey program, which aims to image the faintest distant galaxies using a variety of wavelengths. -- Image Credit: NASA/JPL-Caltech

This from NASA (National Aeronautics and Space Administration) Mission News -

Missing Black Hole Report: Hundreds Found!

NASA -- Pasadena, Calif. -- 10.25.07

Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away.

The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there were hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance.

"Active, supermassive black holes were everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Dickinson is a co-author of two new papers appearing in the Nov. 10 issue of the Astrophysical Journal. Emanuele Daddi of the Commissariat a l'Energie Atomique in France led the research.

The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spent their youths building monstrous black holes at their cores.

For decades, a large population of active black holes has been considered missing. These highly energetic structures belong to a class of black holes called quasars. A quasar consists of a doughnut-shaped cloud of gas and dust that surrounds and feeds a budding supermassive black hole. As the gas and dust are devoured by the black hole, they heat up and shoot out X-rays. Those X-rays can be detected as a general glow in space, but often the quasars themselves can't be seen directly because dust and gas blocks them from our view.
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Daddi and his team initially set out to study 1,000 dusty, massive galaxies that are busy making stars and were thought to lack quasars. The galaxies are about the same mass as our own spiral Milky Way galaxy, but irregular in shape. At 9 to 11 billion light-years away, they existed at a time when the universe was in its adolescence, between 2.5 and 4.5 billion years old.

When the astronomers peered more closely at the galaxies with Spitzer's infrared eyes, they noticed that about 200 of the galaxies gave off an unusual amount of infrared light. X-ray data from Chandra, and a technique called "stacking," revealed the galaxies were, in fact, hiding plump quasars inside. The scientists now think that the quasars heat the dust in their surrounding doughnut clouds, releasing the excess infrared light.

"We found most of the population of hidden quasars in the early universe," said Daddi. Previously, only the rarest and most energetic of these hidden black holes had been seen at this early epoch.
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"Theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharassed galaxies," said co-author David Alexander of Durham University, United Kingdom.
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The new observations were made as part of the Great Observatories Origins Deep Survey, the most sensitive survey to date of the distant universe at multiple wavelengths.

Consistent results were recently obtained by Fabrizio Fiore of the Osservatorio Astronomico di Roma, Italy, and his team. Their results will appear in the Jan. 1, 2008, issue of Astrophysical Journal.
Reference Here>>