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Magnetic Fields Slow Down Stars

June 13, 2012 Leave a comment

Researchers from the Leibniz-Institut für Astrophysik Potsdam (AIP) made simulations of the magnetic fields of stars and compared the results with measurements from a laboratory experiment done at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The aim and result of this experiment was to detect, for the first time, a magnetic instability that had been theoretically predicted but never directly observed in a star. This magnetic effect would enhance the viscosity of hot plasma inside a star, leading to a strong deceleration of its core.

“We have known for years that the Tayler instability is an effective mechanism to explain the deceleration of stars, but until now there was no proof of its existence,“ says Günther Rüdiger, the principal investigator at AIP. “This experiment confirms our numerical predictions very well!“ adds Marcus Gellert, who conducted computer simulations to prepare the experiment.

In order to correlate with the low rotation rates observed in white dwarfs, or neutron stars, which are stars at the end of their life cycle, the core rotation rate of a solar-like star would have to drop by ninety percent. A permanently active magnetic instability could decelerate the core of a star very effectively and would explain observations in a simple and elegant way. The extent to which these laboratory results can be transferred to a real star has to be shown via new simulations and comparisons with observations in the near future. The confirmation of the Tayler instability underlines the importance of magnetic fields in stars and could be an important step towards creating more consistent models of stellar evolution.

Full Story:  http://www.aip.de/en/news/science/gate

NASA’s NuSTAR Mission Lifts Off

June 13, 2012 Leave a comment

NASA’s Nuclear  Spectroscopic Telescope Array (NuSTAR) launched into the morning skies over the  central Pacific Ocean at 9 a.m. PDT (noon EDT) Wednesday,  beginning its mission to unveil secrets of buried black holes and other exotic  objects.
“We have been eagerly awaiting the  launch of this novel X-ray observatory,” said Paul Hertz, NASA’s  Astrophysics Division Director. “With its unprecedented spatial and  spectral resolution to the previously poorly explored hard X-ray region of the  electromagnetic spectrum, NuSTAR will open a new window on the universe and  will provide complementary data to NASA’s larger missions, including Fermi,  Chandra, Hubble and Spitzer.”
NuSTAR will use a unique set of  eyes to see the highest energy X-ray light from the cosmos. The observatory can  see through gas and dust to reveal black holes lurking in our Milky Way galaxy,  as well as those hidden in the hearts of faraway galaxies.
“NuSTAR  will help us find the most elusive and most energetic black holes, to help us  understand the structure of the universe,” said Fiona Harrison, the  mission’s principal investigator at the California Institute of Technology in  Pasadena.
The observatory began its journey  aboard a L-1011 “Stargazer” aircraft, operated by Orbital Sciences  Corporation, Dulles, Va. NuSTAR was perched atop Orbital’s Pegasus XL rocket,  both of which were strapped to the belly of the Stargazer plane. The plane left  Kwajalein Atoll in the central Pacific Ocean one hour before launch. At 9:00:35  a.m. PDT (12:00:35 p.m. EDT), the rocket dropped, free-falling for five seconds  before firing its first-stage motor.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2012-170

Alien Earths Could Form Earlier than Expected

June 13, 2012 Leave a comment

Building a terrestrial planet requires raw materials that weren’t available in the early history of the universe. The Big Bang filled space with hydrogen and helium. Chemical elements like silicon and oxygen – key components of rocks – had to be cooked up over time by stars. But how long did that take? How many of such heavy elements do you need to form planets?

Previous studies have shown that Jupiter-sized gas giants tend to form around stars containing more heavy elements than the Sun. However, new research by a team of astronomers found that planets smaller than Neptune are located around a wide variety of stars, including those with fewer heavy elements than the Sun. As a result, rocky worlds like Earth could have formed earlier than expected in the universe’s history.

Astronomers call chemical elements heavier than hydrogen and helium “metals.” They measure the metal content, or metallicities, of other stars using the Sun as a benchmark. Stars with more heavy elements are considered metal-rich while stars with fewer heavy elements are considered metal-poor.

Latham and his colleagues examined more than 150 stars known to have planets, based on data from NASA’s Kepler spacecraft. They measured the stars’ metallicities and correlated that with the sizes of the associated planets. Large planets tended to orbit stars with solar metallicities or higher. Smaller worlds, though, were found around metal-rich and metal-poor stars alike.

“Giant planets prefer metal-rich stars. Little ones don’t,” explained Latham.

They found that terrestrial planets form at a wide range of metallicities, including systems with only one-quarter of the Sun’s metal content.

Full Story: http://www.cfa.harvard.edu/news/2012/pr201219.html

Spotting Ultrafine Loops in the Sun’s Corona

June 13, 2012 Leave a comment

A key to understanding the dynamics of the sun and what causes the great solar explosions there relies on deciphering how material, heat and energy swirl across the sun’s surface and rise into the upper atmosphere, or corona. Tracking the constantly moving material requires state-of-the-art telescopes with the highest resolution possible. By combining images from NASA’s Solar Dynamics Observatory (SDO) and a new generation telescope called the New Solar Telescope (NST) at Big Bear Solar Observatory in Big Bear City, Calif. scientists have for the first time observed a new facet of the system: especially narrow loops of solar material scattered on the sun’s surface, which are connected to higher lying, wider loops. These ultrafine loops, and their wider cousins may also help with the quest to determine how temperatures rise throughout the corona.
“We’re used to seeing magnetic loops on the sun,” says Philip Goode of the New Jersey Institute of Technology in Newark, NJ, who was a co-author on a paper on these results in the Astrophysical Journal on May 1, 2012. “But we’ve never seen ones lying so low, that were so cold, or that were so narrow. These loops are 10 times narrower and at least 10 times cooler than the higher loops often seen by SDO.”

Full Story: http://www.nasa.gov/mission_pages/sunearth/news/corona-loops.html

Villanova University Astronomers refining method to “age” the most abundant stars in the Universe, and determine their suitability for habitable worlds.

June 13, 2012 Leave a comment

 As a part of their “Living with a Red Dwarf” program, Villanova Astronomers Scott Engle and Ed Guinan are trying to understand how the most common type of star known live its lives, and what kinds of environments they provide for possible life-bearing planets.

Dwarf M-stars (dM stars or M dwarfs) are by far the most numerous stars in the solar neighborhood (and likely the entire Galaxy), comprising 70-80% of all stars (see left-hand figure on next page). dM stars are cool, low luminosity stars with Teff = 2640–3850K and luminosities that range from L = 0.0008–0.06L(for dM8-dM0 stars, respectively). These small, low mass stars (~0.1– 0.6 R; ~0.1 – 0.6 M) have very slow nuclear fusion rates (compared to the more massive solar type stars) and thus have very long lifetimes that range from ~40 Gyr for dM0 stars to longer than 100 Gyr for the lower mass, very low luminosity dM5-8 stars. Given their large numbers and long lifetimes, determining the number of dM stars with planets and assessing planetary habitability is critically important because such studies would indicate how common life is in the universe.

Full Story: http://aas.org/files/Engle_Press_Release.pdf

ESO To Build World’s Biggest Eye On The Sky

June 13, 2012 Leave a comment

ESO is to build the largest optical/infrared telescope in the world. At its meeting in Garching today, the ESO Council approved the European Extremely Large Telescope (E-ELT) Programme, pending confirmation of four so-called ad referendum [1] votes. The E-ELT will start operations early in the next decade.

ESO’s governing body, the Council, met today, at the ESO Headquarters in Garching, Germany. The main topic on the agenda was the start of the European Extremely Large Telescope (E-ELT) Programme — the world’s biggest eye on the sky. The E-ELT will be a 39.3-metre segmented-mirror telescope sited on Cerro Armazones in northern Chile, close to ESO’s Paranal Observatory.

All of ESO’s Member States have already expressed very strong support for the E-ELT project (see eso1150). The Council has today voted in favour of a resolution for the approval of the E-ELT and its first suite of powerful instruments, pending confirmation of the so-called ad referendum votes.

To approve the start of the programme, two-thirds of the Member States (at least ten) had to vote in favour. At the Council meeting Austria, the Czech Republic, Germany, the Netherlands, Sweden and Switzerland voted in favour of the start of the E-ELT programme. Four further countries voted in favour ad referendum: Belgium, Finland, Italy, and the United Kingdom. The remaining four Member States are actively working towards joining the programme in the near future.

Full Story: http://www.eso.org/public/news/eso1225/

NASA and Carnegie Mellon University Celebrate 10 Years of Innovative Partnership

June 13, 2012 Leave a comment

A decade of innovative research, academic excellence and entrepreneurial successes highlighted a celebration of the 10th anniversary of Carnegie Mellon University’s (CMU) Silicon Valley Campus in the NASA Research Park, Moffett Field, Calif., on Saturday, June 8, 2012.
In 2002, the NASA Research Park (NRP) began collaborative partnerships with academia, industry and non-profits to stimulate innovation and education in science and research disciplines critical to space exploration. NASA Ames partnerships were meant to create a dynamic, integrated research community that provides research and development (R&D) leadership into the 21st century. Key areas include astrobiology, information technology, biotechnology and nanotechnology. Today, the NRP has more than 90 partners.
One of the NRP’s first partnerships was Carnegie Mellon University. It has been a hub for developing creative software management leaders and entrepreneurial startups. More than 650 students have graduated from this beacon of technological achievement, and in a wide-variety of R&D programs. Since its inception in 2002, CMU’s Silicon Valley campus has quadrupled in size and helped launch more than a dozen startups.

Full Story: http://www.nasa.gov/topics/nasalife/features/cmu_10_yrs.html

One Ring to Bring Them All: Eclipse Enchants Grand Canyon

June 13, 2012 Leave a comment

Ever see ringlets of sunlight playing in the shadows of a tree or a fiery ring of light in the sky? These incredible effects are the results of an annular solar eclipse like the one that occurred when the moon passed directly between the sun and Earth on Sunday, May 20, 2012. The event was viewable from Japan all the way across the Pacific Ocean to midway through the United States.
Because the moon travels on a slightly tilted orbit compared to the plane of Earth’s orbit around the sun, eclipses do not occur every time the moon comes between the sun and Earth. However, there are two points or “nodes” when the moon does pass through this plane. If either of these nodes coincides with a new moon (when the sun is illuminating only its far side), a solar eclipse will occur. If a node is reached during a full moon, Earth will block the sun’s light, casting a shadow onto the moon causing a lunar eclipse.
An annular eclipse occurs when the moon is too far away from us to completely cover the disk of the sun. This results in an annularity: the ring-shaped outline of the sun that can be seen surrounding the dark new moon. Because of the surreal look of the “ring of fire,” annular eclipses are some of the most impressive celestial events visible from Earth.
This eclipse passed over some of the U.S.’s most famous national parks with the full annularity visible from 33 parks, while an additional 125 parks witnessed a partial eclipse. The NASA Lunar Science Institute (NLSI) at NASA’s Ames Research Center, Moffett Field, Calif., and the National Parks Service took advantage of this rare event and joined forces to facilitate safe viewings for as many people as possible.

Full Story: http://www.nasa.gov/centers/ames/news/features/2012/annular-eclipse.html

Astronomers pinpoint elusive galaxy after decade-long hunt

June 13, 2012 Leave a comment

An international team of astronomers led by Fabian Walter of the Max Planck Institute for Astronomy has managed for the first time to determine the distance of the galaxy HDF850.1, well-known among astronomers as being one of the most productive star-forming galaxies in the observable universe. The galaxy is at a distance of 12.5 billion light years. Hence, we see it as it was 12.5 billion years ago, when the universe was less than 10% of its current age. Even more of a surprise, HDF850.1 turns out to be part of a group of around a dozen protogalaxies that formed within the first billion years of cosmic history — only one of two such primordial clusters known to date. The work is being published in the journal Nature.
The galaxy HDF850.1 was discovered in 1998. It is famous for producing new stars at a rate that is near-incredible even on astronomical scales: a combined mass of a thousand Suns per year. For comparison: an ordinary galaxy such as our own produces no more than one solar mass’s worth of new stars per year. Yet for the past fourteen years, HDF850.1 has remained strangely elusive — its location in space, specifically: its distance from Earth the subject of many studies, but ultimately unknown. How was that possible?
The “Hubble Deep Field”, where HDF850.1 is located, is a region in the sky that affords an almost unparalleled view into the deepest reaches of space. It was first studied extensively using the Hubble Space Telescope. Yet observations using visible light only reveal part of the cosmic picture, and astronomers were quick to follow-up at different wavelengths. In the late 1990s, astronomers using the James Clerk Maxwell Telescope on Hawai’i surveyed the region using submillimeter radiation. This type of radiation, with wavelengths between a few tenths of a millimeter and a millimeter, is particularly suitable for detecting cool clouds of gas and dust.

Full Story: http://www.mpia.de/Public/menu_q2.php?Aktuelles/PR/2012/PR120613/PR_120613_en.html

Planets can form around different types of stars

June 13, 2012 Leave a comment

It had previously been thought that planets were more likely to form around a star if the star had a high content of heavier elements. But new research from the University of Copenhagen, among others, shows that small planets can form around very different types of stars — also stars that are relatively poor in heavy elements. This significantly increases the likelihood that Earth-like planets are widespread in the universe. The results have been published in the prestigious scientific journal, Nature.
3,000 exoplanets, i.e., planets orbiting a star other than the Sun, have now been discovered. 2,300 of these potential planets are being observed with the Kepler satellite by measuring the brightness of the host stars. If a planet moves in front of its star, there is a small decrease in the brightness and if this happens repeatedly, it could be a planet orbiting the star and dimming its light.
A multitude of planets have been discovered so far and by measuring their size it is possible to distinguish between gas giants like Saturn and Jupiter, or whether they are smaller, terrestrial planets like Earth and Mars.

Full Story: http://www.nbi.ku.dk/english/news