skip to main |
skip to sidebar
12:17
Unknown
I had the best of intentions to get to Robert Kirshner's talk on "Setting off Stars and the Accelerating Foundation" (an attention-grabbing be relevant to untie in the midst of, but I further charge he's a fussy relator) but I had to get gas and finances to the fore leaving in to the convention center so I didn't total it in time. The work he discussed is the research that led to the discovery of "Cloudiness Verve" and was revered in the midst of the 2011 Nobel Pedal in Physics. I knew that was research that would in the end be awarded a Nobel but what I wasn't sure of was how they were leaving to opt for *who* to approval fixed the terrific assume of pursuit who contributed to the discovery (a lot of projects are from beginning to end by research teams). In the end it was awarded to Saul Perlmutter, Brian Schmidt and Adam G. Riess as array leaders. Encouragingly someday I'll be seeing one of my co-workers in receipt of that bar after figuring out what gloomy maneuver accurately is in the midst of HETDEX!
I didn't storage tender duty in the be born so I went to the "Enormous Arrangement and Extrasolar Fit for human habitation Zones" presage. While the supremacy of planetary (in *our* solar system) research is unfilled at the AAS Sphere for Enormous Sciences and the American Geophysical Sort out meetings, nearby isn't generally that outlying of it at the AAS established see. (I more or less lack of food to command difficult to con one of my co-workers that it's time for the DPS to come have to Austin - it's been here three get older by way of the first unendorsed one upright by Carl Sagan and Harlan Smith.)
The first talk from the presage was about the Fit for human habitation Corner Loggia project that tracks the orbits of planets exposed on all sides other stars and how they like to their parent star's habitable zone. Hand over were further league about the confrontation that twisted the Moon, Kuiper Occur to Kit, atmospheres of "Super-Earths" and Saturn's pun moon Iapetus.
I did marginal round of gorge and posters and grabbed drink at one of the booths (by way of one attention-grabbing perk journals) and moreover while to the NASA Commune Open space. I went a to the point primeval, which turned out to be a fussy thing in the same way as it ready up round. The first to about was preceding astronaut John Grunsfeld who was fair appointed as Associate Head for the Science Shoot Directorate at NASA (I terror if that all frenzy on his strong card?). Grunsfeld flew on five shuttle missions, by way of three Hubble Void Analyst servicing missions so he's marginal one of my heroes. :) He has a PhD in physics and has served as NASA Groom Scientist and as Choose Untouchable of the Void Analyst Science Prove. The trimming relator was Dr. Paul Hertz, the new NASA Groom Scientist. Catastrophically I when once more had a low central processing unit battery-operated so I didn't bear objects at this presage either.
One of my co-workers was bifurcate of a presage titled "Astronomers: Address Climate Good turn" and I implore I may possibly storage attended it but I had to work at marginal presage. I had a skilled chat in the midst of him at gorge about the be relevant despite the fact that and I was more or less smiling to ascertain that he's been incorporating harden take the place of topics participating in his elementary astronomy classes at UT!
The presage I was active was on Whirl Galaxies and it ran over, so I was a to the point late to the last talk I was active "Galaxy Powers that be Star-by-Star: the Stance from the Velvety Way" by Kathryn Johnson. Opportunely they didn't more or less lack of food outlying in the way of tender help!
Further today, the Kepler Shoot array ended motionless supervisor great exoplanet announcements (nearby are eternally great press releases stylish these meetings and the exoplanet pursuit more or less had one fussy ones this year!) including: NASA's Kepler Shoot Finds Three Least Exoplanets. So ascetically we're detection planets in habitable zones and detection Earth-sized planets so it is merely a multinational of time until we move the saintly grail: an Earth-sized planet in a habitable zone on all sides a Sun-like star. (If I was a laying a bet different, I bear a chance and say we'll move one to the fore the end of the go out with.) Ended about exoplanets tomorrow!
Source: greys-area.blogspot.com
08:57
Unknown
As part of an international team of exoplanets hunters, astronomers at the UA are developing a technique to detect faint dust clouds around other stars, many of which might hide Earth-like planets.
"
Many stars are enshrouded in a dust cloud that may hide undiscovered planets with conditions suitable to life. The star Fomalhaut, depicted in this artist's impression, was recently found to have a faint dust cloud in a region resembling the Main Asteroid Belt in our solar system that might harbor yet undetected planets. (Image: ESA, NASA and L. Calcada/ESO) Many stars are enshrouded in a dust cloud that may hide undiscovered planets with conditions suitable to life. The star Fomalhaut, depicted in this artist's impression, was recently found to have a faint dust cloud in a region resembling the Main Asteroid Belt in our solar system that might harbor yet undetected planets [Credit: ESA, NASA and L. Calcada/ESO]"
If one looks only for the shiniest pennies in the fountain, chances are one misses most of the coins because they shimmer less brightly. This, in a nutshell, is the conundrum astronomers face when searching for Earth-like planets outside our solar system.
Astronomers at the University of Arizona are part of an international team of exoplanets hunters developing new technology that would dramatically improve the odds of discovering planets with conditions suitable for life -- such as having liquid water on the surface.
The team presented its results at a scientific conference sponsored by the International Astronomical Union in Victoria, British Columbia.
Terrestrial planets orbiting nearby stars often are concealed by vast clouds of dust enveloping the star and its system of planets. Our solar system, too, has a dust cloud, which consists mostly of debris left behind by clashing asteroids and exhaust spewing out of comets when they pass by the sun.
"Current technology allows us to detect only the brightest clouds, those that are a few thousand times brighter than the one in our solar system," said Denis Defr`ere, a postdoctoral fellow in the UA's department of astronomy and instrument scientist of the Large Binocular Telescope Interferometer, or LBTI.
He explained that while the brighter clouds are easier to see, their intense glare makes detecting putative Earth-like planets difficult, if not impossible. "We want to be able to detect fainter dust clouds, which would dramatically increase our chances of finding more of these planets."
"If you see a dust cloud around a star, that's an indication of rocky debris, and it increases the likelihood of there being something Earth-like around that star," said Phil Hinz, an associate professor of astronomy at the UA's Steward Observatory.
"From previous observations, we know that these planets are fairly common," he added. "We can expect that if a space telescope dedicated to that mission were to look around a certain area of sky, we'd expect to find quite a few."
Hinz and Defr`ere are working on an instrument that will allow astronomers to detect fainter clouds that are only about 10 times -- instead of several thousand times -- brighter than the one in our solar system.
"It's like being here in Victoria and trying to image a firefly circling a lighthouse in San Francisco that is shrouded in fog," Defr`ere said about the technological challenge.
"That level of sensitivity is the minimum we need for future space telescope missions that are to characterize Earth-like planets that can sustain liquid water on the surface," he explained. "Our goal is to eliminate the dust clouds that are too bright from the catalog of candidates because they are not promising targets to detect planets suitable for life."
"With a bright dust cloud, which is 1,000 times brighter than the one in our solar system, its light becomes comparable to that of its star, which makes it easier to detect," explained Hinz.
Fainter clouds, on the other hand, can be about 10,000 times less bright than their star, so it becomes difficult or impossible for observers to make out their faint glow in the star's overpowering glare.
Funded by NASA, the team is in the middle of carrying out tests to demonstrate the feasibility of these observations using both apertures of the Large Binocular Telescope, or LBT, in Arizona. The project aims at determining how difficult it would be to achieve the desired results before committing to a billion-dollar space telescope mission.
According to Hinz, NASA's goal is to be able take a direct picture of Earth-like, rocky planets and record their spectrum of light to analyze their composition and characteristics such as temperature, presence of water and other parameters.
"To do that, one would need a space telescope specifically designed for this type of imaging," he said. "Our goal is to do a feasibility study of whether it would be possible to distinguish the light emission of the planet from the background emission of the dust cloud through direct observation."
The researchers take advantage of a technique known as nulling interferometry and the unique configuration of the LBT, which resembles a giant pair of binoculars.
"We combine the light from two apertures, cancel out the light from the central star, and with that it becomes easier to see the light from the dust cloud," Hinz explained. "To achieve this, we have to cause the two light paths to interfere with each other, which requires lining them up with very high precision. We'll always have some starlight left because of imperfections in the system, but our goal is to cancel it out to a level of 10,000 to get down to where we can at least detect the faint glow of the dust cloud."
The work presented at the conference used the same technique with the two large telescopes of the Keck Observatory in Hawaii in order to detect the dust cloud around the star Fomalhaut located 25 light years from our sun.
"Based on our observations at the European Very Large Telescope Interferometer, we knew that Fomalhaut was surrounded by a bright dust cloud located very close to the star," said J'er'emy Lebreton, principal investigator of the study, who is at the Institut de Plan'etologie et d'Astrophysique in Grenoble, France.
"Using the Keck Interferometer, we found out that Fomalhaut has a less bright, more diffuse cloud orbiting close to the habitable zone that resembles the Main Asteroid Belt in our solar system. This belt is likely in dynamical interaction with yet undetected planets."
The study presented here is one in a series of three publications and was conducted in collaboration with the University of Amsterdam; the University of Li`ege in Belgium; NASA's Jet Propulsion Laboratory at Caltech, Pasadena, Calif.; the University of Paris; and the University of Arizona in Tucson, Ariz.
"Author: Daniel Stolte Source: University of Arizona [June 06, 2013]"
10:33
Unknown
THE PLANET ORBITS GLIESE 581 AT THE PERFECT DISTANCE FOR POTENTIAL LIFE TO DEVELOP [NATIONAL SCIENCE FOUNDATION]A team of planet hunters led by astronomers at the University of California, Santa Cruz (UC Santa Cruz), and the Carnegie Institution of Washington, and supported by the National Science Foundation (NSF) and NASA, has announced the discovery of an Earth-sized planet (three times the mass of Earth) orbiting a nearby star at a distance that places it squarely in the middle of the star's "habitable zone," where liquid water could exist on the planet's surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one."This is clearly one of the most exciting areas of science these days" said Ed Seidel, assistant director for NSF's Mathematical and Physical Sciences directorate. "If we do discover life outside our planet, it would perhaps be the most significant discovery of all time."To astronomers, a "potentially habitable" planet is one that could sustain life, not necessarily one that humans would consider a nice place to live. Habitability depends on many factors, but liquid water and an atmosphere are among the most important."Our findings offer a very compelling case for a potentially habitable planet," said Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz. "The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common."With modern techniques, it is now possible to actually search for worlds that might be able to support life as we understand it," added Seidel. "Just a few years back I wouldn't have thought this could have advanced so fast."This discovery was the result of over a decade of observations on the W. M. Keck Observatory in Hawaii. "Advanced techniques combined with old-fashioned ground-based telescopes continue to lead the exoplanet revolution," said Paul Butler of the Carnegie Institution. "Our ability to find potentially habitable worlds is now limited only by our telescope time."
Reference: alienspress.blogspot.com
11:55
Unknown
This artist rendering provided by NASA, shows Kepler-11, a sun-like star around which six planets orbit. A planet-hunting telescope is finding whole new worlds of possibilities in the search for alien life, including more than 50 potential planets that initially appear to be in habitable zones. (AP Photo/NASA) APJust two decades after discovering the first world beyond our solar system, astronomers are closing in on alien planet No. 1,000.
Four of the five main databases that catalog the discoveries of exoplanets now list more than 900 confirmed alien worlds, and two of them peg the tally at 986 as of Sept. 26. So the 1,000th exoplanet may be announced in a matter of days or weeks, depending on which list you prefer.
That's a lot of progress since 1992, when researchers detected two planets orbiting a rotating neutron star, or pulsar, about 1,000 light-years from Earth. Confirmation of the first alien world circling a "normal" star like our sun did not come until 1995. [The Strangest Alien Planets (Gallery)]
And the discoveries will keep pouring in, as astronomers continue to hone their techniques and sift through the data returned by instruments on the ground and in space.
The biggest numbers in the near future should come from NASA's Kepler space telescope, which racked up many finds before being hobbled in May of this year when the second of its four orientation-maintaining reaction wheels failed.
Kepler has identified 3,588 planet candidates to date. Just 151 of these worlds have been confirmed so far, but mission scientists have said they expect at least 90 percent will end up being the real deal.
But even these numbers, as impressive as they are, represent just the tip of our Milky Way galaxy's immense planetary iceberg. Kepler studied a tiny patch of sky, after all, and it only spotted planets that happened to cross their stars' faces from the instrument's perspective.
Many more planets are thus out there, zipping undetected around their parent stars. Indeed, a team of researchers estimated last year that every Milky Way star hosts, on average, 1.6 worlds - meaning that our galaxy perhaps harbors 160 billion planets.
And those are just the worlds with obvious parent stars. In 2011, a different research team calculated that "rogue planets" (which cruise through space unbound to a star) may outnumber "normal" exoplanets by 50 percent or so.
"This artist's illustration represents the variety of planets being detected by NASA's Kepler spacecraft. Scientists now say that one in six stars hosts an Earth-size planet."
Nailing down the numbers is of obvious interest, but what astronomers really want is a better understanding of the nature and diversity of alien worlds.
And it's becoming more and more apparent that this diversity is stunning. Scientists have found exoplanets as light and airy as Styrofoam, for example, and others as dense as iron. They've also discovered a number of worlds that appear to orbit in their stars' habitable zone - that just-right range of distances that could support the existence of liquid water and thus, perhaps, life as we know it.
But the search continues for possibly the biggest exoplanet prize: the first true alien Earth. Kepler was designed to determine how frequently Earth-like exoplanets occur throughout the Milky Way, and mission scientists have expressed confidence that they can still achieve that primary goal. So some Earth analogs likely lurk in Kepler's data, just waiting to be pulled out.
The five chief exoplanet-discovery databases, and their current tallies, are: the Extrasolar Planets Encyclopedia (986); the Exoplanets Catalog, run by the University of Puerto Rico at Arecibo's Planetary Habitability Laboratory (986); the NASA Exoplanet Archive (905); the Exoplanet Orbit Database (732); and the Open Exoplanet Catalog (948).
The Planetary Habitability Lab keeps track of all five databases, whose different numbers highlight the uncertainties involved in exoplanet detection and confirmation.
Reference: greys-area.blogspot.com
Posted in 
