Posts Tagged ‘astronomy’
ALMA, the World’s Largest Radio Telescope, Grabs Its First Images
Appropriately enough, the first images captured the Antennae Galaxies, a pair of colliding galaxies replete with stars and stellar nurseries. ALMA’s 39- and 23-foot dish antennae can resolve areas of dense, cold gas that other telescopes could not detect.
sits in the high Chilean desert, about 16,000 feet above sea level and above much of the interfering atmosphere. These pictures were made with 12 telescopes situated relatively close together; science observations during the next few months will be even clearer.
Closer-situated antennae yield a wide field of view, so astronomers can search for items they want to study in more detail. Moving the antennae farther apart provides a narrower focus, like using a finer lens on a regular telescope. Instead of tunable knobs, ALMA has 192 separate antennae pads for the huge dishes to be moved around.
Astronomers submitted more than 900 research proposals for the telescope’s first 9 months of observations, which the European Southern Observatory whittled down to about 100. A few key subjects:
A nearby star system called AU Microscopii, just 33 light-years away, with an infant star harboring a ring of planetisimals;
The dusty disk surrounding HD142527, a young star 400 light-years away, which has enough material to make a dozen Jupiters;
and the great Sagittarius A, the supermassive black hole at the center of the Milky Way.
ALMA observes light at millimeter and sub-millimeter wavelengths, allowing observations of the farthest and oldest phenomena in the observable universe. It’s powerful enough to study the cold, dark remnants of exploded stars, including the first stars, which died a few hundred million years after the Big Bang — that’s an era known as the cosmic dawn.
While this is all going on, more of the 100-ton antennae will keep being added until the observatory is complete sometime in 2013.
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Pluto May Be Hiding Oceans Underneath Its Frozen Exterior
Winners of the 2011 Astronomy Photographer of the Year Contest
Click here to launch a gallery of the best of the winning photos.
From among the winners, we've put together a gallery of our favorites, including auroras, supernova remnant and beautiful views of the Milky Way. These photos almost make us ready to pack up and move out of the city so we can reacquaint ourselves with the stars. Almost.
A Supernova Fades Gloriously into a Supernova Remnant
The supernova debris has been dimming in the years since its discovery, but a team of astronomers announced today that the debris is now beginning to brighten again. This means that it is being lit by a different power source, and is a sign of 1987a's transition from supernova to supernova remnant.
When a supernova forms, most of its light comes from the radioactive decay of elements created in the explosion, which decreases and fades over time. As you can see in the image above, 1987a is surrounded by a ring of detritus that flew off the progenitor star before it exploded. Inside the ring, the fish-shaped cloud of star guts is expanding ever outward. Some of this material is starting to hit the surrounding ring, which is creating shock waves that produce X-rays. These X-rays, combined with shock heating, are the new power source that is causing the supernova remnant to brighten.
When the rest of the expanding stellar debris hits, the ring will shred and little of the former star's history will remain. Until then, scientists can study the last several thousand years of the stars life by observing the swirls of gas and interstellar stuff.
Advanced Optics That Let Telescopes See Deep Into Space Will Help Microscopes See Deep Inside Cells
In astronomy, adaptive optics fixes the blurring of deep-space images by correcting for the turbulence in Earth’s atmosphere. These techniques have allowed the Keck telescopes in Hawaii to resolve deep-space objects with greater clarity than the Hubble Space Telescope. In microscopy, blurring is caused by the flowing cytoplasm of living cells, and adaptive optics can be used to correct for that, too.
Electrical engineers at the new W. M. Keck Center for Adaptive Optical Microscopy at UC Santa Cruz will develop new adaptive optics systems that can peer inside stem cells, for instance, to see how they differentiate.
Recent advances in optical microscopes have allowed scientists to and to in real time, both major improvements that increase resolution without harming living cells. But even the best microscope images are only clear up to the surface of the cells, according to William Sullivan, a UCSC cell biology professor. When peering inside the cell, things start to get blurry.
Adaptive optical microscopy would work by establishing a biological “guide star” as a reference point, and correcting for the distortions caused by cytoplasm flow.
In astronomy, telescopes use a star or a laser as a control beacon by which atmospheric blurring can be measured. The Keck Observatory shines a laser to create a fake “guide star” about 60 miles up — above most of the atmosphere — and uses it to measure starlight distortions. The light is bounced off a deformable mirror that smooths out the image. This process repeats every millisecond.
The UC Santa Cruz project is developing genetically engineered fluorescent proteins to serve as guide stars. The ideal protein would be small and it would look like a dot, providing a point source of light, a UC Santa Cruz explains. Sullivan is working with fly embryos and using a protein that tags a the center of a chromosome as the guide star. The rest of the chromosome is tagged with a different color.
Eventually, the researchers hope to develop a suite of guide star proteins that would help illuminate any kind of tissue.
“This has the potential to open up vast areas of cell biology that have been opaque to us,” Sullivan said.
X-Ray Astronomy Uncovers A Pretty Cosmic Anomaly
