Jan 8 2013

From The Space Library

RELEASE: 13-005 - NASA'S HUBBLE REVEALS ROGUE PLANETARY ORBIT FOR FOMALHAUT B --WASHINGTON -- Newly released NASA Hubble Space Telescope images of a vast debris disk encircling the nearby star Fomalhaut and a mysterious planet circling it may provide forensic evidence of a titanic planetary disruption in the system. Astronomers are surprised to find the debris belt is wider than previously known, spanning a section of space from 14 to nearly 20 billion miles from the star. Even more surprisingly, the latest Hubble images have allowed a team of astronomers to calculate the planet follows an unusual elliptical orbit that carries it on a potentially destructive path through the vast dust ring. The planet, called Fomalhaut b, swings as close to its star as 4.6 billion miles, and the outermost point of its orbit is 27 billion miles away from the star. The orbit was recalculated from the newest Hubble observation made last year. We are shocked. This is not what we expected, said Paul Kalas of the University of California at Berkeley and the SETI Institute in Mountain View, Calif. The Fomalhaut team led by Kalas considers this circumstantial evidence there may be other planet-like bodies in the system that gravitationally disturbed Fomalhaut b to place it in such a highly eccentric orbit. The team presented its finding Tuesday at the 221st meeting of the American Astronomical Society in Long Beach, Calif. Among several scenarios to explain Fomalhaut b's 2,000-year-long orbit is the hypothesis that an as yet undiscovered planet gravitationally ejected Fomalhaut b from a position closer to the star, and sent it flying in an orbit that extends beyond the dust belt. Hot Jupiters get tossed through scattering events, where one planet goes in and one gets thrown out, said co-investigator Mark Clampin of NASA's Goddard Space Flight Center in Greenbelt, Md. "This could be the planet that gets thrown out." Hubble also found the dust and ice belt encircling the star Fomalhaut has an apparent gap slicing across the belt. This might have been carved by another undetected planet. Hubble's exquisite view of the dust belt shows irregularities that strongly motivate a search for other planets in the system. If its orbit lies in the same plane with the dust belt, then Fomalhaut b will intersect the belt around 2032 on the outbound leg of its orbit. During the crossing, icy and rocky debris in the belt could crash into the planet's atmosphere and create the type of cosmic fireworks seen when Comet Shoemaker-Levy 9 crashed into Jupiter. Most of the fireworks from collisions will be seen in infrared light. However, if Fomalhaut b is not co-planar with the belt, the only thing to be seen will be a gradual dimming of Fomalhaut b as it travels farther from the star. Kalas hypothesized that Fomalhaut b's extreme orbit is a major clue in explaining why the planet is unusually bright in visible light, but very dim in infrared light. It is possible the planet's optical brightness originates from a ring or shroud of dust around the planet, which reflects starlight. The dust would be rapidly produced by satellites orbiting the planet, which would suffer extreme erosion by impacts and gravitational stirring when Fomalhaut b enters into the planetary system after a millennium of deep freeze beyond the main belt. An analogy can be found by looking at Saturn, which has a tenuous, but very large dust ring produced when meteoroids hit the outer moon Phoebe. The team has also considered a different scenario where a hypothetical second dwarf planet suffered a catastrophic collision with Fomalhaut b. The collision scenario would explain why the star Fomalhaut has a narrow outer belt linked to an extreme planet. But in this case the belt is young, less than 10,000 years old, and it is difficult to produce energetic collisions far from the star in such young systems. Fomalhaut is a special system because it looks like scientists may have a snapshot of what our solar system was doing 4 billion years ago. The planetary architecture is being redrawn, the comet belts are evolving, and planets may be gaining and losing their moons. Astronomers will continue monitoring Fomalhaut b for decades to come because they may have a chance to observe a planet entering an icy debris belt that is like the Kuiper Belt at the fringe of our own solar system.

RELEASE: 13-006 - NASA, ESA TELESCOPES FIND EVIDENCE FOR ASTEROID BELT AROUND VEGA --WASHINGTON -- Astronomers have discovered what appears to be a large asteroid belt around the star Vega, the second brightest star in northern night skies. The scientists used data from NASA's Spitzer Space Telescope and the European Space Agency's (ESA) Herschel Space Observatory, in which NASA plays an important role. The discovery of an asteroid belt-like band of debris around Vega makes the star similar to another observed star called Fomalhaut. The data are consistent with both stars having inner, warm belts and outer, cool belts separated by a gap. This architecture is similar to the asteroid and Kuiper belts in our own solar system. What is maintaining the gap between the warm and cool belts around Vega and Fomalhaut? The results strongly suggest the answer is multiple planets. Our solar system's asteroid belt, which lies between Mars and Jupiter, is maintained by the gravity of the terrestrial planets and the giant planets, and the outer Kuiper belt is sculpted by the giant planets. Our findings echo recent results showing multiple-planet systems are common beyond our sun, said Kate Su, an astronomer at the Steward Observatory at the University of Arizona. Su presented the results Tuesday at the American Astronomical Society meeting in Long Beach, Calif., and is lead author of a paper on the findings accepted for publication in the Astrophysical Journal. Vega and Fomalhaut are similar in other ways. Both are about twice the mass of our sun and burn a hotter, bluer color in visible light. Both stars are relatively nearby at about 25 light-years away. The stars are thought to be around 400 million years old, but Vega could be closer to its 600 millionth birthday. Fomalhaut has a single candidate planet orbiting it, Fomalhaut b, which orbits at the inner edge of its cometary belt. The Herschel and Spitzer telescopes detected infrared light emitted by warm and cold dust in discrete bands around Vega and Fomalhaut, discovering the new asteroid belt around Vega and confirming the existence of the other belts around both stars. Comets and the collisions of rocky chunks replenish the dust in these bands. The inner belts in these systems cannot be seen in visible light because the glare of their stars outshines them. Both the inner and outer belts contain far more material than our own asteroid and Kuiper belts. The reason is twofold: the star systems are far younger than our own, which has had hundreds of millions more years to clean house, and the systems likely formed from an initially more massive cloud of gas and dust than our solar system. The gap between the inner and outer debris belts for Vega and Fomalhaut also proportionally corresponds to the distance between our sun's asteroid and Kuiper belts. This distance works out to a ratio of about 1:10, with the outer belt 10 times farther away from its host star than the inner belt. As for the large gap between the two belts, it is likely there are several undetected planets, Jupiter-sized or smaller, creating a dust-free zone between the two belts. A good comparison star system is HR 8799, which has four known planets that sweep up the space between two similar disks of debris. Overall, the large gap between the warm and the cold belts is a signpost that points to multiple planets likely orbiting around Vega and Fomalhaut, said Su. If unseen planets do in fact orbit Vega and Fomalhaut, these bodies will not likely stay hidden. Upcoming new facilities such as NASA's James Webb Space Telescope should be able to find the planets, said paper co-author Karl Stapelfeldt, chief of the Exoplanets and Stellar Astrophysics Laboratory at NASA's Goddard Space Flight Center in Greenbelt, Md.

RELEASE: 13-010 - SOFIA SPOTS RECENT STARBURSTS IN THE MILKY WAY GALAXY'S CENTER --WASHINGTON -- Researchers using the Stratospheric Observatory for Infrared Astronomy (SOFIA) have captured new images of a ring of gas and dust seven light-years in diameter surrounding the supermassive black hole at the center of the Milky Way, and of a neighboring cluster of extremely luminous young stars embedded in dust cocoons. The images of our galaxy's circumlunar ring (CNR) and its neighboring quintuplet cluster (QC) are the subjects of two posters presented this week during the American Astronomical Society's meeting in Long Beach, Calif. Ryan Lau of Cornell University and his collaborators studied the CNR. Matt Hankins of the University of Central Arkansas in Conway is lead author of the other paper, regarding the QC. SOFIA is a highly modified Boeing 747SP aircraft carrying a telescope with an effective diameter of 100 inches (2.54 meters) to altitudes as high as 45,000 feet (13.7 kilometers). The images were obtained during SOFIA flights in 2011 with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) instrument built by a team with principal investigator Terry Herter of Cornell. FORCAST offered astronomers the ability to see the CNR and QC regions and other exotic cosmic features whose light is obscured by water vapor in Earth's atmosphere and interstellar dust clouds in the mid-plane of the Milky Way. Neither ground-based observatories on tall mountain peaks nor NASA's orbiting Hubble and Spitzer space telescopes can see them.

RELEASE: 13-011 - NASA TELESCOPES SEE WEATHER PATTERNS IN BROWN DWARF --WASHINGTON -- Astronomers using NASA's Spitzer and Hubble space telescopes have probed the stormy atmosphere of a brown dwarf, creating the most detailed "weather map" yet for this class of cool, star-like orbs. The forecast shows wind-driven, planet-sized clouds enshrouding these strange worlds. Brown dwarfs form out of condensing gas, as stars do, but lack the mass to fuse hydrogen atoms and produce energy. Instead, these objects, which some call failed stars, are more similar to gas planets with their complex, varied atmospheres. The new research is a stepping stone toward a better understanding not only of brown dwarfs, but also of the atmospheres of planets beyond our solar system. With Hubble and Spitzer, we were able to look at different atmospheric layers of a brown dwarf, similar to the way doctors use medical imaging techniques to study the different tissues in your body, said Daniel Apai, the principal investigator of the research at the University of Arizona in Tucson, who presented the results at the American Astronomical Society meeting Tuesday in Long Beach, Calif. A study describing the results, led by Esther Buenzli, also of the University of Arizona, is published in the Astrophysical Journal Letters. The researchers turned Hubble and Spitzer simultaneously toward a brown dwarf with the long name of 2MASSJ22282889-431026. They found that its light varied in time, brightening and dimming about every 90 minutes as the body rotated. But more surprising, the team also found the timing of this change in brightness depended on whether they looked using different wavelengths of infrared light. These variations are the result of different layers or patches of material swirling around the brown dwarf in windy storms as large as Earth itself. Spitzer and Hubble see different atmospheric layers because certain infrared wavelengths are blocked by vapors of water and methane high up, while other infrared wavelengths emerge from much deeper layers. Unlike the water clouds of Earth or the ammonia clouds of Jupiter, clouds on brown dwarfs are composed of hot grains of sand, liquid drops of iron, and other exotic compounds, said Mark Marley, research scientist at NASA's Ames Research Center in Moffett Field, Calif., and co-author of the paper. "So this large atmospheric disturbance found by Spitzer and Hubble gives a new meaning to the concept of extreme weather." According to Buenzli, this is the first time researchers can probe variability at several different altitudes at the same time in the atmosphere of a brown dwarf. "Although brown dwarfs are cool relative to other stars, they are actually hot by earthly standards. This particular object is about 1,100 to 1,300 degrees Fahrenheit (600 to 700 degrees Celsius)," Buenzli said. What we see here is evidence for massive, organized cloud systems, perhaps akin to giant versions of the Great Red Spot on Jupiter, said Adam Showman, a theorist at the University of Arizona involved in the research. "These out-of-sync light variations provide a fingerprint of how the brown dwarf's weather systems stack up vertically. The data suggest regions on the brown dwarf where the weather is cloudy and rich in silicate vapor deep in the atmosphere coincide with balmier, drier conditions at higher altitudes -- and vice versa." Researchers plan to look at the atmospheres of dozens of additional nearby brown dwarfs using both Spitzer and Hubble. From studies such as this we will learn much about this important class of objects, whose mass falls between that of stars and Jupiter-sized planets. said Glenn Wahlgren, Spitzer Program scientist at NASA Headquarters in Washington. "This technique will see extensive use when we are able to image individual exoplanets."

MEDIA ADVISORY: M13-007 - NASA OFFERS NEWS MEDIA ACCESS TO TDRS-K SPACECRAFT JAN. 11 --CAPE CANAVERAL, Fla. -- NASA's Tracking and Data Relay Satellite-K (TDRS-K), set to launch this month, will be the focus of a media opportunity at 10 a.m. EST Friday, Jan. 11, at the Astrotech Space Operations facility in Titusville, Fla. The spacecraft is the first of three next generation satellites designed to ensure vital operational continuity for NASA by expanding the lifespan of the fleet, which consists of 7 satellites in geostationary orbit. The spacecraft provide tracking, telemetry, command, and high bandwidth data return services for numerous science and human exploration missions orbiting Earth. These include NASA's Hubble Space Telescope and the International Space Station. TDRS-K has a high-performance solar panel designed for more spacecraft power to meet the growing S-band communications requirements. Spokespersons representing NASA's Goddard Space Flight Center in Greenbelt, Md.; the Launch Services Program at the agency's Kennedy Space Center in Florida; and United Launch Alliance will be available for questions and interviews. TDRS-K is scheduled to liftoff aboard an Atlas V 401 rocket from Cape Canaveral Air Force Station on Jan. 29 in a launch window that extends from 8:52 to 9:32 p.m. EST. Boeing Space and Intelligence Systems in El Segundo, Calif., built the TDRS-K. NASA's Space Communications and Navigation Program, part of the Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington, is responsible for the TDRS network. NASA's Launch Services Program at Kennedy is responsible for launch management. United Launch Alliance provides the Atlas V rocket and launch service.

MEDIA ADVISORY: M13-008 - NASA HOLDS BRIEFINGS JAN. 17 TO PREVIEW SPACE STATION SCIENCE AND ACTIVITIES --HOUSTON -- NASA's Johnson Space Center in Houston will hold two news conferences Thursday, Jan. 17, to preview the upcoming Expedition 35 and 36 missions aboard the International Space Station. NASA Television and the agency's website will carry the briefings live. At 11 a.m. CST (noon EST), the International Space Station Program and Science Overview briefing will cover mission priorities and objectives. These will include several visiting spacecraft, such as multiple Russian Progress resupply ships, the fourth European Automated Transfer Vehicle, the fourth Japanese H-II Transfer Vehicle, the SpaceX Dragon cargo craft and the debut demonstration and supply flights of the Orbital Sciences Cygnus spacecraft. Four Russian spacewalks also are scheduled during the 5 1/2-month mission with the possible addition of U.S.-based spacewalks. At 1 p.m. (2 p.m. EST), Expedition 35/36 crew members Chris Cassidy of NASA and Pavel Vinogradov and Alexander Misurkin of the Russian Federal Space Agency (Roscosmos) will discuss their mission. They are set to launch to the orbiting laboratory aboard a Soyuz spacecraft March 27 and return to Earth Sept. 11. Cassidy, Vinogradov and Misurkin are three of the six crew members comprising Expeditions 35 and 36. When they arrive at the station, they will join NASA astronaut Tom Marshburn, Canadian Space Agency astronaut Chris Hadfield and Roscosmos cosmonaut Roman Romanenko. For those attending the briefing at Johnson, the deadline for U.S. reporters to request credentials is Jan. 15. The deadline for international residents is Jan. 9. Reporters wishing to attend at other NASA centers should contact those centers' newsrooms for specific deadlines.