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UCSB Professor Develops Cutting-Edge Detector Technology For Astronomical Observations

November 5, 2013 Leave a comment

Semiconductors have had a nice run, but for certain applications, such as astrophysics, they are being edged out by superconductors. Ben Mazin, assistant professor of physics at UC Santa Barbara, has developed a superconducting detector array that measures the energy of individual photons. The design and construction of an instrument based on these arrays, as well as an analysis of its commissioning data, appear in the Publications of the Astronomical Society of the Pacific.

“What we have made is essentially a hyperspectral video camera with no intrinsic noise,” Mazin said. “On a pixel-per-pixel basis, it’s a quantum leap from semiconductor detectors; it’s as big a leap going from film to semiconductors as it is going from semiconductors to these superconductors. This allows all kinds of really interesting instruments based on this technology.”

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Hubble’s New Shot Of Proxima Centauri, Our Nearest Neighbor

November 5, 2013 Leave a comment

Credit: ESA/Hubble & NASA

Credit: ESA/Hubble & NASA

Proxima Centauri lies in the constellation of Centaurus (The Centaur), just over four light-years from Earth. Although it looks bright through the eye of Hubble, as you might expect from the nearest star to the Solar System, Proxima Centauri is not visible to the naked eye. Its average luminosity is very low, and it is quite small compared to other stars, at only about an eighth of the mass of the sun.

However, on occasion, its brightness increases. Proxima is what is known as a flare star,” meaning that convection processes within the star’s body make it prone to random and dramatic changes in brightness. The convection processes not only trigger brilliant bursts of starlight but, combined with other factors, mean that Proxima Centauri is in for a very long life. Astronomers predict that this star will remain middle-aged — or a “main sequence” star in astronomical terms — for another four trillion years, some 300 times the age of the current Universe.

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Former Missile-Tracking Telescope Helps Reveal Fate Of Baby Pulsar

November 5, 2013 Leave a comment

A radio telescope once used to track ballistic missiles has helped astronomers determine how the magnetic field structure and rotation of the young and rapidly rotating Crab pulsar evolves with time. The findings are published in the journal Science today (Friday).

The Crab pulsar is a neutron star which formed in a massive cosmic explosion seen in both Europe and China in AD 1054 as a bright star in the daytime sky. Now rotating 30 times a second, this highly-compact star emits beams of radio waves that, like a lighthouse, produce flashes each time it rotates. The star itself is only about 25 km across but contains the mass of nearly 1 million Earths.

Professor Andrew Lyne and his colleagues from The University of Manchester report on a steady change in these flashes during a 22-year experiment watching the star, telling us about its very strong magnetic field and helping us learn about the otherwise-inaccessible interior of the star.

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Could A Milky Way Supernova Be Visible From Earth In Next 50 Years?

November 5, 2013 Leave a comment

Astronomers at The Ohio State University have calculated the odds that, sometime during the next 50 years, a supernova occurring in our home galaxy will be visible from Earth.

The good news: they’ve calculated the odds to be nearly 100 percent that such a supernova would be visible to telescopes in the form of infrared radiation.

The bad news: the odds are much lower—dipping to 20 percent or less—that the shining stellar spectacle would be visible to the naked eye in the nighttime sky.

Yet, all this is great news to astronomers, who, unlike the rest of us, have high-powered infrared cameras to point at the sky at a moment’s notice. For them, this study suggests that they have a solid chance of doing something that’s never been done before: detect a supernova fast enough to witness what happens at the very beginning of a star’s demise. A massive star “goes supernova” at the moment when it’s used up all its nuclear fuel and its core collapses, just before it explodes violently and throws off most of its mass into space.

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Magnetic ‘Force Field’ Shields Giant Gas Cloud During Collision With Milky Way

November 5, 2013 Leave a comment

Image: Bill Saxton, NRAO/AUI/NSF

Image: Bill Saxton, NRAO/AUI/NSF

Doom may be averted for the Smith Cloud, a gigantic streamer of hydrogen gas that is on a collision course with the Milky Way Galaxy. Astronomers using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) and Robert C. Byrd Green Bank Telescope (GBT) have discovered a magnetic field deep in the cloud’s interior, which may protect it during its meteoric plunge into the disk of our Galaxy.

This discovery could help explain how so-called high velocity clouds (HVCs) remain mostly intact during their mergers with the disks of galaxies, where they would provide fresh fuel for a new generation of stars.

Currently, the Smith Cloud is hurtling toward the Milky Way at more than 150 miles per second and is predicted to impact in approximately 30 million years. When it does, astronomers believe, it will set off a spectacular burst of star formation. But first, it has to survive careening through the halo, or atmosphere, of hot ionized gas surrounding the Milky Way.

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