Showing posts with label star. Show all posts
Showing posts with label star. Show all posts

The Voyager spacecraft-100 Year Star-ship



The Voyager spacecraft, exposed in this artist's description barreling away from the sun, would take tens of thousands of years to attain the nearest star to Earth. Scientists and researchers with 100 Year Star-ship are probing faster space travel and other elements needed to send a human crew past the Solar System.

Although NASA has ended its space take program and the latest mission beyond our planet occupied a robotic Mars rover, rather than astronauts, a group of scientists and dreamers is working out how to send humans to the remote stars.

The plan, called 100 Year Star-ship, has original funding from the U.S. Defense Advanced Research Projects Agency (DARPA). It's snooping what would be required to take a ship and crew away from our solar system within the next century.

Lasers From Keck telescopes Discover Quirky Star Close To Middle Of Milky Method

quirky star near center of Milky Way

 The powerful Lasers from the twin Keck telescopes of the Keck Observatory on Mauna Kea point to the center of the Milky Way galaxy, where scientists have establish a second star orbiting a super massive black hole. Now a day’s Scientists using the Keck Observatory atop Mauna Kea have originate a second star in a surprisingly fast orbit around the black hole at the middle of the Milky Way galaxy.

The discovery, published world today in the great journal Science, may help astronomers determine if Einstein was right in his fundamental calculation of how black holes warp space and time, said UCLA physicist Andrea Ghez, organizer of the discovery group.

The shining star, known as S0-102, orbits the black hole in 11.5 years, a virtual sprint that allows astronomers to study an entire orbit for perturbations that offer clues to the black hole’s structure. Let’s before this finding, astronomers knew of only 1 star near the black hole with a very short orbit: S0-2, which completes a circuit (CKT) in 16 years. Both are in the assemblage Sagittarius.

WISE Delivers Millions of Galaxies, Stars, Asteroids

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Astronomers across the globe can now sift through hundreds of millions of galaxies, stars and asteroids collected in the first bundle of data from NASA's Wide-field Infrared Survey Explorer (WISE) mission. "Starting today thousands of new eyes will be looking at WISE data, and I expect many surprises," said Edward (Ned) Wright of UCLA, the mission's principal investigator. WISE launched into space on Dec. 14, 2009 on a mission to map the entire sky in infrared light with greatly improved sensitivity and resolution over its predecessors. From its polar orbit, it scanned the skies about one-and-a-half times while collecting images taken at four infrared wavelengths of light. It took more than 2.7 million images over the course of its mission, capturing objects ranging from faraway galaxies to asteroids relatively close to Earth.

Like other infrared telescopes, WISE required coolant to chill its heat-sensitive detectors. When this frozen hydrogen coolant ran out, as expected, in early October, 2010, two of its four infrared channels were still operational. The survey was then extended for four more months, with the goal of finishing its sweep for asteroids and comets in the main asteroid belt of our solar system. The mission's nearby discoveries included 20 comets, more than 33,000 asteroids between Mars and Jupiter, and 133 near-Earth objects (NEOs), which are those asteroids and comets with orbits that come within 28 million miles of Earth's path around the sun. The satellite went into hibernation in early February of this year.

Today, WISE is taking the first major step in meeting its primary goal of delivering the mission's trove of objects to astronomers. Data from the first 57 percent of the sky surveyed is accessible through an online public archive. The complete survey, with improved data processing, will be made available in the spring of 2012. A predecessor to WISE, the Infrared Astronomical Satellite, served a similar role about 25 years ago, and those data are still valuable to astronomers today. Likewise, the WISE legacy is expected to endure for decades. "We are excited that the preliminary data contain millions of newfound objects," said Fengchuan Liu, the project manager for WISE at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "But the mission is not yet over the real treasure is the final catalog available a year from now, which will have twice as many sources, covering the entire sky and reaching even deeper into the universe than today's release."

NASA's Spitzer Discovers Time-Delayed Jets

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Astronomers have discovered that two symmetrical jets shooting away from opposite sides of a blossoming star are experiencing a time delay: knots of gas and dust from one jet blast off four-and-a-half years later than identical knots from the other jet. The finding, which required the infrared vision of NASA's Spitzer Space Telescope, is helping astronomers understand how jets are produced around forming stars, including those resembling our sun when it was young. "More studies are needed to determine if other jets have time delays," said Alberto Noriega-Crespo of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, who is a co-author of the new study to be published in the April 1 issue of Astrophysical Journal Letters.

"Now we know that in at least one case, there appears to be a delay, which tells us that some sort of communication may be going on between the jets that takes time to occur." Jets are an active phase in a young star's life. A star begins as a collapsing, roundish cloud of gas and dust. By ejecting supersonic jets of gas, the cloud slows down its spinning. As material falls onto the growing star, it develops a surrounding disk of swirling material and twin jets that shoot off from above and below the disk, like a spinning top. Once the star ignites and shines with starlight, the jets will die off and the disk will thin out. Ultimately, planets may clump together out of material left in the spinning disk.

The discovery of the time delay, in the jets called Herbig-Haro 34, has also led the astronomers to narrow in on the size of the zone from which the jets originate. The new Spitzer observations limit this zone to a circle around the young star with a radius of 3 astronomical units. An astronomical unit is the distance between our sun and Earth. This is about 10 times smaller than previous estimates. "Where we stand today on Earth was perhaps once a very violent place where high-velocity gas and dust were ejected from the disk circling around our very young sun," said Alex Raga of the Universidad Nacional Autónoma de México, the first author of the paper. "If so, the formation of planets like Earth depends on how and when this phenomenon ended. Essentially, every star like our own sun has gone through a similar cloud-disk-jets formation process."

WISE see An blast Of Infrared Light


This oddly colorful nebula is the supernova remnant IC 443 as seen by NASA's Wide-field Infrared review Explorer, or WISE. Also known as the Jellyfish nebula, IC 443 is mainly interesting because it provides a look into how stellar explosions relate with their environment. IC 443 can be found near the star Eta Geminorum, which lies near Castor, one of the twins in the group Gemini. Just like human beings, stars have a life cycle they are born, mature and finally die. The way in which stars die depends on their mass. Stars with mass alike to the sun characteristically become planetary nebulae at the end of their lives, whereas stars with many times the sun's collection explode as supernovae.

IC 443 is the remains of a star that go supernova somewhere between 5,000 and 10,000 years ago. The explosion from the supernova sent out shock waves that travel through space, sweeping up and heating the nearby gas and dust in the interstellar medium, and creating the supernova remnant seen in this image. What is unusual about the IC 443 is that its shell-like form has two halve that have dissimilar radii, structures and emissions. The better northeastern shell, seen here as the violet colored semi circle on the top left of the supernova remainder, is composed of sheet like filaments that are emit light from iron, neon, silicon and oxygen gas atoms, in addition to dust particle, all heated by the blast from the supernova.

The smaller southern shell, seen here in a bright cyan color on the base half of the image, is constructed of denser clumps and knots chiefly emitting light from hydrogen gas and heated dust. These clumps are division of a molecular cloud, which can be seen in this image as the greenish cloud hurtful across IC 443 from the northwest to southeast. The color differences seen in this image represent dissimilar wavelengths of infrared emission. The differences in color are also the result of difference in the energies of the shock influence hitting the interstellar medium. The northeastern shell was most likely shaped by a fast shock wave, whereas the southern shell was perhaps created by a slow shock wave.

So you Think you can Solve a Cosmology Puzzle?

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Cosmologists have come up with a new way to solve their problems. They are inviting scientists, including those from totally unrelated fields, to participate in a grand competition. The idea is to spur outside interest in one of cosmology's trickiest problems measuring the invisible dark matter and dark energy that permeate our universe. The results will help in the development of new space missions, designed to answer fundamental questions about the history and fate of our universe. "We're hoping to get more computer scientists interested in our work," said cosmologist Jason Rhodes of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who is helping to organize the challenge, which begins on Dec. 3, 2010.

"Some of the mathematical problems in our field are the same as those in machine-learning applications for example facial recognition software." JPL and several European Universities, including The University of Edinburgh and University College London in the United Kingdom, are helping to support the event, which is funded by a European Union group called Pattern Analysis, Statistical Modelling and Computation Learning. The principal investigator is Thomas Kitching of the University of Edinburgh. This year, the competition, which has operated since 2008, is called GREAT 2010, after GRavitational lEnsing Accuracy Testing. The challenge is to solve a series of puzzles involving distorted images of galaxies. Occasionally in nature, a galaxy is situated behind a clump of matter that is causing the light from the galaxy to bend.

The result is a magnified and skewed image of the galaxy. In the most extreme cases, the warping results in multiple images and even a perfect ring, called an Einstein Ring after Albert Einstein, who predicted the effect. But most of the time, the results are more subtle and a galaxy image is distorted just a tiny bit not even enough to be perceived by eye. This is called weak gravitational lensing, or just weak lensing for short. Weak lensing is a powerful tool for unlocking the fabric of our universe. Only four percent of our universe consists of the stuff that makes up people, stars and anything with atoms. Twenty-four percent is dark matter a mysterious substance that we can't see but which tugs on the regular matter we can see. Most of our universe, 72 percent, consists of dark energy, which is even more baffling than dark matter.

Astronomers Probe 'Sandbar' Between Islands of Galaxies

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Astronomers have caught sight of an unusual galaxy that has illuminated new details about a celestial "sandbar" connecting two massive islands of galaxies. The research was conducted in part with NASA's Spitzer Space Telescope. These "sandbars," or filaments, are known to span vast distances between galaxy clusters and form a lattice-like structure known as the cosmic web. Though immense, these filaments are difficult to see and study in detail. Two years ago, Spitzer's infrared eyes revealed that one such intergalactic filament containing star-forming galaxies ran between the galaxy clusters called Abell 1763 and Abell 1770.

Now these observations have been bolstered by the discovery, inside this same filament, of a galaxy that has a rare boomerang shape and unusual light emissions. Hot gas is sweeping the wandering galaxy into this shape as it passes through the filament, presenting a new way to gauge the filament's particle density. Researchers hope that other such galaxies with oddly curved profiles could serve as signposts for the faint threads, which in turn signify regions ripe for forming stars.

"These filaments are integral to the evolution of galaxy clusters among the biggest gravitationally bound objects in the universe as well as the creation of new generations of stars," said Louise Edwards, a postdoctoral researcher at the California Institute of Technology in Pasadena, and lead author of a study detailing the findings in the Dec. 1 issue of the Astrophysical Journal Letters. Her collaborators are Dario Fadda, also at Caltech, and Dave Frayer from the National Science Foundation's National Radio Astronomy Observatory, based in Charlottesville, Virginia.

Chandra Finds Evidence for Stellar Cannibalism

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Evidence that a star has recently engulfed a companion star or a giant planet has been found using NASA's Chandra X-ray Observatory. The likely existence of such a "cannibal" star provides new insight into how stars and the planets around them may interact as they age. The star in question, known as BP Piscium (BP Psc), appears to be a more evolved version of our Sun, but with a dusty and gaseous disk surrounding it. A pair of jets several light years long blasting out of the system in opposite directions has also been seen in optical data. While the disk and jets are characteristics of a very young star, several clues including the new results from Chandra suggest that BP Psc is not what it originally appeared to be.

Instead, astronomers have suggested that BP Psc is an old star in its so-called red giant phase. And, rather than being hallmarks of its youth, the disk and jets are, in fact, remnants of a recent and catastrophic interaction whereby a nearby star or giant planet was consumed by BP Psc. When stars like the Sun begin to run of nuclear fuel, they expand and shed their outer layers. Our Sun, for example, is expected to swell so that it nearly reaches or possibly engulfs Earth, as it becomes a red giant star. "It appears that BP Psc represents a star-eat-star Universe, or maybe a star-eat-planet one," said Joel Kastner of the Rochester Institute of Technology, who led the Chandra study. "Either way, it just shows it's not always friendly out there."

Several pieces of information have led astronomers to rethink how old BP Psc might be. First, BP Psc is not located near any star-forming cloud, and there are no other known young stars in its immediate vicinity. Secondly, in common with most elderly stars, its atmosphere contains only a small amount of lithium. Thirdly, its surface gravity appears to be too weak for a young star and instead matches up with one of an old red giant. Chandra adds to this story. Young, low-mass stars are brighter than most other stars in X-rays, and so X-ray observations can be used as a sign of how old a star may be. Chandra does detect X-rays from BP Psc, but at a rate that is too low to be from a young star. Instead, the X-ray emission rate measured for BP Psc is consistent with that of rapidly rotating giant stars.

NASA's Kepler Mission Discovers Two Planets Transiting Same Star

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NASA's Kepler spacecraft has discovered the first confirmed planetary system with more than one planet crossing in front of, or transiting, the same star. The transit signatures of two distinct planets were seen in the data for the sun-like star designated Kepler-9. The planets were named Kepler-9b and 9c. The discovery incorporates seven months of observations of more than 156,000 stars as part of an ongoing search for Earth-sized planets outside our solar system. The findings will be published in Thursday's issue of the journal Science. Kepler's ultra-precise camera measures tiny decreases in the stars' brightness that occur when a planet transits them. The size of the planet can be derived from these temporary dips.

The distance of the planet from the star can be calculated by measuring the time between successive dips as the planet orbits the star. Small variations in the regularity of these dips can be used to determine the masses of planets and detect other non-transiting planets in the system. In June, mission scientists submitted findings for peer review that identified more than 700 planet candidates in the first 43 days of Kepler data. The data included five additional candidate systems that appear to exhibit more than one transiting planet. The Kepler team recently identified a sixth target exhibiting multiple transits and accumulated enough follow-up data to confirm this multi-planet system.

"Kepler's high quality data and round-the-clock coverage of transiting objects enable a whole host of unique measurements to be made of the parent stars and their planetary systems," said Doug Hudgins, the Kepler program scientist at NASA Headquarters in Washington. Scientists refined the estimates of the masses of the planets using observations from the W.M. Keck Observatory in Hawaii. The observations show Kepler-9b is the larger of the two planets, and both have masses similar to but less than Saturn. Kepler-9b lies closest to the star with an orbit of about 19 days, while Kepler-9c has an orbit of about 38 days. By observing several transits by each planet over the seven months of data, the time between successive transits could be analyzed.

Perseids Complete 2010 August Light Show

http://nasa-satellites.blogspot.com/The 2010 Perseid meteor shower is drawing to a close after painting brilliant streaks across the August nighttime skies. This year's shower began around July 17, peaked August 12-13 and will be officially over by August 24. "The Perseids are a great shower, one I look forward to every year. And this year didn’t disappoint!" said Dr. Bill Cooke, head of NASA's Meteoroid Environment Office, located at the Marshall Space Flight Center in Huntsville, Ala. The Perseid meteor shower has been observed for at least 2,000 years and is associated with the comet 109P/Swift-Tuttle, which orbits the sun once every 133 years or so.

Each year in August, the Earth passes through a cloud of the comet's debris. These bits of ice and dust travel around 132,000 mph, burning up about 56 miles overhead in the Earth's atmosphere to create one of the best meteor showers of the year. The shower is called the "Perseids" because the meteors appear to come from the direction of the constellation Perseus. The Perseids can be of any brightness, but most are as bright as Polaris North Star or brighter. This meteor shower, however, is known for producing "fireball" meteors that appear at least as bright as the planet Venus as they burn up in the night sky. The bits of Swift-Tuttle debris range in size from one millimeter to several centimeters the larger the particle hitting the Earth's atmosphere, the brighter the meteor trail.

The streak of light in a meteor trail isn’t a view of the particle, but the ionization trail. Ionization happens as the speeding particle causes electrons to be ripped away from atoms in the atmosphere. The meteor trails from a Perseid meteor can be many miles long and remain visible for several seconds. If you missed the Perseids this year, another good meteor shower is coming in December. The Geminids will happen between Dec. 7-17, with the best viewing after moonset Dec. 13-14. The forecast is for 50-120 meteors per hour at the peak on Dec. 14 at roughly 2 in the morning. The Geminids are named for the constellation Gemini, the direction from which the meteors appear to originate. 

Pulverized Planet Dust May Lie Around Double Stars

http://nasa-satellites.blogspot.com/Tight double-star systems might not be the best places for life to spring up, according to a new study using data from NASA's Spitzer Space Telescope. The infrared observatory spotted a surprisingly large amount of dust around three mature, close-orbiting star pairs. Where did the dust come from? Astronomers say it might be the aftermath of tremendous planetary collisions. "This is real-life science fiction," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. "Our data tell us that planets in these systems might not be so lucky collisions could be common. It's theoretically possible that habitable planets could exist around these types of stars, so if there happened to be any life there, it could be doomed."

Drake is the principal investigator of the research, published in the Aug.19 issue of the Astrophysical Journal Letters. The particular class of binary, or double, stars in the study are about as snug as stars get. Named RS Canum Venaticorums, or RS CVns for short, they are separated by only about two million miles (3.2 million kilometers), or two percent of the distance between Earth and our sun. The stellar pairs orbit around each other every few days, with one face on each star perpetually locked and pointed toward the other. The close-knit stars are similar to the sun in size and are probably about a billion to a few billion years old roughly the age of our sun when life first evolved on Earth. But these stars spin much faster, and, as a result, have powerful magnetic fields, and giant, dark spots.

The magnetic activity drives strong stellar winds gale-force versions of the solar wind that slow the stars down, pulling the twirling duos closer over time. And this is where the planetary chaos may begin. As the stars cozy up to each other, their gravitational influences change, and this could cause disturbances to planetary bodies orbiting around both stars. Comets and any planets that may exist in the systems would start jostling about and banging into each other, sometimes in powerful collisions. This includes planets that could theoretically be circling in the double stars' habitable zone, a region where temperatures would allow liquid water to exist. Though no habitable planets have been discovered around any stars beyond our sun at this point in time, tight double-star systems are known to host planets; for example, one system not in the study, called HW Vir, has two gas-giant planets.

NASA's Great Observatories Witness a Galactic Spectacle

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A new image of two tangled galaxies has been released by NASA's Great Observatories. The Antennae galaxies, located about 62 million light-years from Earth, are shown in this composite image from the Chandra X-ray Observatory (blue), the Hubble Space Telescope (gold and brown), and the Spitzer Space Telescope (red). The Antennae galaxies take their name from the long, antenna-like arms seen in wide-angle views of the system. These features were produced in the collision. The collision, which began more than 100 million years ago and is still occurring, has triggered the formation of millions of stars in clouds of dusts and gas in the galaxies.

The most massive of these young stars have already sped through their evolution in a few million years and exploded as supernovas. The X-ray image from Chandra shows huge clouds of hot, interstellar gas, which have been injected with rich deposits of elements from supernova explosions. This enriched gas, which includes elements such as oxygen, iron, magnesium and silicon, will be incorporated into new generations of stars and planets. The bright, point-like sources in the image are produced by material falling onto black holes and neutron stars that are remnants of the massive stars. Some of these black holes may have masses that are almost one hundred times that of the sun.

The Spitzer data show infrared light from warm dust clouds that have been heated by newborn stars, with the brightest clouds lying in the overlap region between the two galaxies. The Hubble data reveal old stars and star-forming regions in gold and white, while filaments of dust appear in brown. Many of the fainter objects in the optical image are clusters containing thousands of stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. 

Puff, the Magic Dragon?

cloud
A dragon-shaped cloud of dust seems to fly with the stars in a new image from NASA's Spitzer Space Telescope (bottom). In visible light (top), the creature disappears into the clouds perhaps it's "frolicking in the autumn mist" like Puff, the Magic Dragon, from the famous Peter, Paul and Mary song. The infrared image has revealed that this creature, a dark cloud called M17 SWex, is forming stars at a furious rate but has not yet spawned the most massive type of stars, known as O stars.

Such stellar behemoths, however, light up the M17 nebula at the image's center and have also blown a huge "bubble" in the gas and dust that forms M17's luminous left edge. The stars and gas in this region are now passing though the Sagittarius spiral arm of the Milky Way , touching off a galactic "domino effect." The youngest episode of star formation is playing out inside the dusty dragon as it enters the spiral arm. Over time, this area will flare up like the bright M17 nebula, glowing in the light of young massive stars.

An older burst of star formation blew the bubble seen in the region to the far left, called M17 EB. The visible-light view of the area clearly shows the bright M17 nebula, as well as the glowing hot gas filling the "bubble" to its left. However the M17 SWex "dragon" is hidden within dust clouds that are opaque to visible light. It takes an infrared view to catch the light from these shrouded regions and reveal the earliest stages of star formation.