Tuesday, April 22, 2014

Unique Pair of Supermassive Black Holes Discovered by XMM-Newton

Artist’s impression of a pair of black holes. One of them is accreting the 'debris' of the disrupted star, while the second is temporarily interrupting the stream of gas toward the other black hole. Credit: ESA - C. Carreau

A pair of supermassive black holes in orbit around one another have been spotted by ESA's XMM-Newton spacecraft. This is the first time such a pair have been seen in an ordinary galaxy. They were discovered because they ripped apart a star when the space observatory happened to be looking in their direction. Most massive galaxies in the Universe are thought to harbour at least one supermassive black hole at their centre. Two supermassive black holes are the smoking gun that the galaxy has merged with another. Thus, finding binary supermassive black holes can tell astronomers about how galaxies evolved into their present-day shapes and sizes. To date, only a few candidates for close binary supermassive black holes have been found. All are in active galaxies where they are constantly ripping gas clouds apart, in the prelude to crushing them out of existence. The findings are published in the May 10 issue of the “Astrophysical Journal”, and appeared online today at the astrophysics preprint server.

Space Station Crew Set to Conduct Spacewalk and Release Cargo Ship

Steve Swanson works on a rack inside the Kibo laboratory. Image Credit: NASA TV

Expedition 39 is finalizing preparations for a 2.5 hour spacewalk scheduled to begin 9:20 a.m. EDT Wednesday. The station crew is also getting ready to send off a Russian space freighter for two days of tests before it redocks again Friday morning. Spacewalkers Steve Swanson and Rick Mastracchio will install a spare backup computer on the S0 truss located on top of the Destiny laboratory module Wednesday morning. They will remove the old computer which failed April 11 after being shut down then restarted for a periodic health check. The duo was joined by Commander Koichi Wakata for a short spacewalk procedure conference. The trio also set up the Quest airlock, where they will stage their excursion, and readied spacewalk tools.

Astronauts on New Mission to Warn of Asteroid 'Cosmic Roulette'

As members of an elite band of cosmic explorers, they are among the few to have gone beyond the final frontier and looked down on the Earth from space. Now, inspired by the unique perspective they gained of their home planet – and armed with startling new data about the scale of the threat it faces from asteroid strikes – a group of former NASA astronauts are on an extraordinary mission to save the world. Fourteen months after an asteroid exploded over Chelyabinsk, Russia, on a scale equivalent to 30 Hiroshima bombs, the B612 Foundation, a non-profit group founded by Apollo 9 astronaut Rusty Schweickart and space shuttle astronaut Ed Lu, are warning that only "blind luck" has so far saved it from worse.

An X-ray View of the COSMOS Field

Credit: ESA/XMM-Newton/Gunther Hasinger, Nico Cappelluti, and the XMM-COSMOS collaboration

When we gaze up at the night sky, we are only seeing part of the story. Unfortunately, some of the most powerful and energetic events in the Universe are invisible to our eyes – and to even the best optical telescopes. Luckily, these events are not lost; they appear vividly in the high-energy sky, making them visible to space-based telescopes like ESA's XMM-Newton, which observes the Universe in the X-ray part of the spectrum. This image shows a patch of sky from the COSMOS survey, as viewed by XMM-Newton. COSMOS is a project studying how galaxies form and evolve, gathering observations using a variety of ground- and space-based telescopes. This image alone features about two thousand supermassive black holes, and over a hundred clusters of galaxies.

‘Upside-Down Planet’ Reveals New Method for Studying Binary Star Systems

An image of the Sun used to simulate what the sun-like star in a self-lensing binary star system might look like. Credit: NASA

What looked at first like a sort of upside-down planet has instead revealed a new method for studying binary star systems, discovered by a University of Washington (UW) student astronomer. Working with UW astronomer Eric Agol, doctoral student Ethan Kruse has confirmed the first “self-lensing” binary star system — one in which the mass of the closer star can be measured by how powerfully it magnifies light from its more distant companion star. Though our sun stands alone, about 40 percent of similar stars are in binary (two-star) or multi-star systems, orbiting their companions in a gravitational dance. Kruse’s discovery confirms an astronomer’s prediction in 1973, based on stellar evolution models of the time, that such a system should be possible. A paper by Kruse and Agol was published in the April 18 edition of Science. Like so many interesting discoveries, this one happened largely by accident.

The Coolest Destination for Exchange Students: Mars

Credit: eca.state.gov

The U.S. Department of State’s Bureau of Educational and Cultural Affairs (ECA) is launching a new type of exchange with a virtual field trip to Mars. ECA’s newest initiative, The Collaboratory, in partnership with NASA’s Digital Learning Network™, Google’s Connected Classrooms Program, and the U.S. Embassies in Buenos Aires and Managua, will engage middle school students from classes in Argentina, Nicaragua, as well as those in New Jersey, Texas, and Washington, D.C. in collaborative science activities.

Mountains on Iapetus May Have Come from Space

Raw image from Cassini space probe of the equatorial ridge on Saturn's moon Iapetus. Image: NASA

A combined team of researchers from Brown University in Rhode Island and the Lunar and Planetary Institute in Texas is suggesting in a paper they've uploaded to the preprint server arXiv, that an equatorial mountainous ridge on one of Saturn's moons has an exogenic origin. They are basing their theory on 3D models of the moon they've created and an analysis of the types of peaks present. Iapetus, the 3rd largest of Saturn's approximately 60 moons, is distinct for two reasons. One is its odd two-tone coloring; the other is the back-bone looking mountain range straddling part of its equator.

Russia Mulls Over Huge 60 m Telescope

Artist's impression of the European Extremely Large Telescope (E-ELT) in its enclosure on Cerro Armazones, a 3060-metre mountaintop in Chile's Atacama Desert. Credit: ESO/L. Calçada

The rector of Moscow State University, Viktor Sadovnichy, has unveiled plans for a massive 60 m optical telescope on the Canary Islands. If built, the telescope would be the world's largest and would hunt for Earth-like planets around other stars, says Sadovnichy. But the plans have divided researchers, with some Russian astronomers saying the country should not build its own facility but join the European Southern Observatory (ESO) instead. According to Vladimir Lipunov, director of the Space Monitoring Laboratory at Moscow State University, the telescope would be built by Russia, Spain and possibly Switzerland and Germany, with Russia getting a quarter of the observing time at the facility. The so-far-unnamed telescope would dwarf all existing – and currently planned – facilities, including the 39 m European Extremely Large Telescope (E-ELT) and 25 m Giant Magellan Telescope, both to be based in Chile, as well as the Thirty Meter Telescope to be built in Hawaii.