A University of Oklahoma assistant professor and colleagues have identified two white dwarf stars considered the oldest and closest known to man. Astronomers identified these 11- to 12-billion-year-old white dwarf stars only 100 light years away from Earth. These stars are the closest known examples of the oldest stars in the Universe forming soon after the Big Bang, according to the OU researcher.
Mukremin Kilic, assistant professor of physics and astronomy in the OU College of Arts and Sciences and lead author on a recently published paper, announced the discovery. Kilic says, “A white dwarf is like a hot stove; once the stove is off, it cools slowly over time. By measuring how cool the stove is, we can tell how long it has been off. The two stars we identified have been cooling for billions of years.”
The EXOEarths team (Centro de Astrofísica da Universidade do Porto – CAUP), in collaboration with Geneva University, did a joint analysis of data from the HARPS spectrograph and the Kepler satellite. This analysis revealed that the orbits of other planetary systems are aligned, like in a disk, just like in our own Solar System.
Recently, the HARPS spectrograph and the Kepler satellite made a census of the planetary population around stars like our own, revealing a bounty of planetary systems. A follow-up study lead by members of the EXOEarths team (Centro de Astrofísica da Universidade do Porto – CAUP), in collaboration with Geneva University, did a joint analysis of the data which showed that the planetary orbits in a system are strongly aligned, like in a disk, just as we have in our own solar system.
ESA’s Herschel Space Observatory has studied the dusty belt around the nearby star Fomalhaut. The dust appears to be coming from collisions that destroy up to thousands of icy comets every day.
Fomalhaut is a young star, just a few hundred million years old, and twice as massive as the Sun. Its dust belt was discovered in the 1980s by the IRAS satellite, but Herschel’s new images of the belt show it in much more detail at far-infrared wavelengths than ever before.
Bram Acke, at the University of Leuven in Belgium, and colleagues analysed the Herschel observations and found the dust temperatures in the belt to be between –230 and –170ºC. However, because Fomalhaut is slightly off-centre and closer to the southern side of the belt, the southern side is warmer and brighter than the northern side.
An international team of researchers led by Masamune Oguri at Kavli IPMU and Naohisa Inada at Nara National College of Technology conduced an unprecedented survey of gravitationally lensed quasars, and used it to measure the expansion history of the universe. The result provides strong evidence that the expansion of the universe is accelerating. There were several observations that suggested the accelerated cosmic expansion, including distant supernovae for which the 2011 Nobel Prize in Physics was awarded. The team’s result confirms the accelerated cosmic expansion using a completely different approach, which strengthens the case for dark energy. This result will be published in The Astronomical Journal.
Full Story: http://www.ipmu.jp/node/1281
Fang Lizhi, a major voice for human rights and democracy and a pioneering scientist in his native China, continued to advance the field of astrophysics at the UA for more than 20 years before he died last week.
Human rights activist Fang Lizhi, who died last week at age 76, had been a professor in the University of Arizona department of physics and an adjunct professor with the UA’s Steward Observatory for more than 20 years, where he made highly regarded contributions to astrophysics.
Fang was world renowned for his outspoken and active role in promoting human rights in his native China.
Considered an “undesirable element” by the Chinese government, Fang was dismissed from the Chinese nuclear program and reassigned in 1958 to the University of Science and Technology of China, or USTC, which is regarded as China’s equivalent of the Massachusetts Institute of Technology.
Full Story: http://uanews.org/node/46176
NASA’s 747 Shuttle Carrier Aircraft (SCA) with space shuttle Discovery mounted atop will fly approximately 1,500 feet above various parts of the Washington, D.C. metropolitan area on Tuesday, April 17.
The flight, in cooperation with the Federal Aviation Administration, is scheduled to occur between 10 and 11 a.m. EDT. NASA Television and the agency’s web site will provide live coverage.
The exact route and timing of the flight depend on weather and operational constraints. However, the aircraft is expected to fly near a variety of landmarks in the metropolitan area, including the National Mall, Reagan National Airport, National Harbor and the Smithsonian’s Udvar-Hazy Center. When the flyover is complete, the SCA will land at Dulles International Airport.
One day in the fall of 2011, Neil Sheeley, a solar scientist at the Naval Research Laboratory in Washington, D.C., did what he always does – look through the daily images of the sun from NASA’s Solar Dynamics Observatory (SDO).
But on this day he saw something he’d never noticed before: a pattern of cells with bright centers and dark boundaries occurring in the sun’s atmosphere, the corona. These cells looked somewhat like a cell pattern that occurs on the sun’s surface — similar to the bubbles that rise to the top of boiling water — but it was a surprise to find this pattern higher up in the corona, which is normally dominated by bright loops and dark coronal holes.
Sheeley discussed the images with his Naval Research Laboratory colleague Harry Warren, and together they set out to learn more about the cells. Their search included observations from a fleet of NASA spacecraft called the Heliophysics System Observatory that provided separate viewpoints from different places around the sun. They describe the properties of these previously unreported solar features, dubbed “coronal cells,” in a paper published online in The Astrophysical Journal on March 20, 2012 that will appear in print on April 10.