Posts for 'Solar Physics' Category

Astronomers have discovered evidence of the oldest and most distant cosmic event ever detected, a burst from a dying star that occurred 13 billion years ago, very soon after the birth of the universe. Scientists hope the discovery of the ancient explosion will bring new insights into the evolution of the cosmos. Astronomers say the high-energy gamma-ray burst from the dying star occurred 630 million years after the so-called Big Bang that is believed to have created the universe nearly 14 billion years ago.

The discovery suggests the so-called Dark Age of the universe, the period after the Big Bang before first-generation stars could fill the cosmos with light, ended much earlier than previously thought. Prior to the discovery, the earliest stellar explosion on record occurred 200 million years later and involved a star much closer to Earth. Nial Tanvir of the University of Leicester in England headed one of two teams of scientists that discovered the gamma ray blast marking the death of the star.

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Models of the solar corona typically simplify the energy equation by neglecting important energy transport processes. These "polytropic" models are useful but also have significant limitations. Through scientific and technical advances enabled by CISM, we have significantly improved our coronal modeling capability to include the effects of coronal heating, the conduction of heat parallel to the magnetic field lines, radiative losses, and the acceleration of the solar wind by Alfven waves.

We refer to this as the "thermodynamic" MHD model. A principal difficulty in this type of model is related to the extremely steep temperature and density gradients in the transition region, a consequence of the balance between conduction of heat from the hot corona and radiation loss in the transition region. Recent work on the MAS coronal model has provided an important advance that effectively treats the transition region as slightly broadened without compromising the coronal solution.

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Astronomers have been turning the world's most powerful telescopes toward Jupiter, the solar system's largest planet, ever since Australian amateur astronomer Anthony Wesley discovered a new dark marking on the planet, apparently the scar from an impacting asteroid or comet, on the night of July 19. MIT professor of planetary science Richard Binzel says the impact highlights the role that Jupiter, with its powerful gravitational field, plays in protecting the Earth and other planets from such impacts.

"Jupiter is the big bully of the solar system," says Binzel, who specializes in observations of asteroids and comets. But if it's a bully to some celestial objects, it's the protector of others. "Under Jupiter's influence, many objects end up being cast into the sun, some get cast out [of the solar system], and some end up striking Jupiter itself. The net result is that Jupiter keeps the inner solar system more cleaned out than it might otherwise be."

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The Astronomy club and Physics department are looking for student artists who would like to help build a scale model of the Solar system. These to-scale models will be set up on Tappan Square during Commencement Week. If you’re interested in helping build representations of the planets, Sun, and moon (no word yet on Pluto), contact Henry McCaslin. The Astronomy Club will partially reimburse materials costs, and your name as designer/artist will accompany this display.

Models are due by May 18, so start thinking today! (Maybe incorporate it into your Big Parade float?)

Scientists have found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in near-Earth space. They are now looking to model how these changes affect orbiting satellites, including the GPS system.

The results were obtained from coordinated in-situ measurements performed by ESA's four Cluster satellites along with the two Chinese/ESA Double Star satellites. Under normal solar conditions, GPS satellites orbit within the magnetosphere-the protective magnetic bubble carved out by Earth's magnetic field.

But when solar activity increases, the picture changes significantly: compressed and particles become energized, exposing satellites to higher doses of radiation that can perturb signal reception. Such increased solar activity affects all satellites, not only the GPS system.

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Meteors that smashed into the planet Mercury 3.9 billion years ago are giving scientists a glimpse deep into the tiny planet's interior and providing clues to how it has evolved in the eons since. The 430-mile-wide Rembrandt impact basin, first seen by NASA's Maryland-built Messenger spacecraft during two flybys last year, preserves cracks created during ancient upheavals from beneath the basin, as well as ridges formed like wrinkles as the planet cooled and shrank.

"This is really exciting, because this pattern of tectonic land forms is different than anything we see anywhere in the solar system," said Thomas Watters, a scientist with the Smithsonian Institution in Washington who is part of the Messenger team.

Messenger was designed and built at the Johns Hopkins University's Applied Physics Laboratory, and its operations center is on the lab's campus near Laurel. Another flyby is planned for Sept. 29. If all goes well, the spacecraft in March 2011 will become the first to orbit the planet.

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There's always something exciting or beautiful happening in space. Here we are, minding our own business in the midst of a slow news week...The space shuttle Discovery's launch was delayed for safety reasons again (yikes, for the fifth time since February 12th?).

The International Space Station dodged some orbital debris. Our intense campaign of waiting for the government to assign a new NASA administrator has raged onward now for several months. All these things are surely important, but each leaves us somehow lacking in the "news" department.

Then out of the blue, wham-o, the universe dishes up something that forces us to stop and appreciate the wonder of it all. That happened to me today... and now I'm making sure it will happen to you too. I just got an e-mail from a good friend who was looking for his Barlow lens. I borrowed it, oh, at least five years ago (seriously!) and never returned it.

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The Astrophysics Group is offering standard, STFC funded research studentships in astronomy and astrophysics, and EPSRC (CASE) funded research studentship in plasma physics for students wishing to start Ph.D.s in October 2009. We would be pleased to hear from anyone (from the UK or abroad) who is interested in research in these areas. In addition we have a thriving programme for research masters degrees (MSc) for self funded students.

The Department of Physics at the University of Bristol hosts a vigorous and expanding Astrophysics Group headed by Professor M. Birkinshaw, the Coldrick Professor of Astrophysics and Cosmology. The group conducts research in the general areas of Galactic and extra-galactic astronomy and cosmology, including both theoretical and observational topics. Currently active research programmes include the following.

The Sunyaev-Zel'dovich Effect-The scattering of the microwave background radiation by gas in clusters of galaxies is used to study cluster atmospheres and as a tool to measure the parameters that define the large-scale structure of the Universe.

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Russia launched a solar observatory Friday to study the connection between the sun and Earth, marking the first Russian science mission of its scale in more than four years.The Coronas Photon spacecraft will spend the next three years circling Earth with a suite of instruments designed to measure energetic particles produced by solar flares, the solar atmosphere, and solar activity's relationship with magnetic storms around Earth.

The 4,200-pound satellite launched from the Plesetsk Cosmodrome in northern Russia at 1330 GMT (8:30 a.m. EST). A Tsyklon 3 rocket hauled the satellite to an orbital perch about 310 miles above the planet and released the craft less than 45 minutes after liftoff, project officials said.

The launch was the first flight of a large Russian science mission in more than four years. Russia has orbited a flurry of smaller satellites since then, but none have equaled Coronas Photon's science ambitions, sophistication, or mass.

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New research by teams of MIT scientists and students could lead to cheaper and more efficient solar cells in the next few years, either by incorporating materials that are so abundant that they could support a major boom in the industry or by cutting production costs for conventional solar cells.

Tonio Buonassisi, the SMA Assistant Professor of Mechanical Engineering and Manufacturing, says the research is a systematic attempt to explore the kinds of materials that could be used for future solar cells. Some reports on the progress by Buonassisi and his co-workers were presented on Dec. 3 at the Materials Research Society meeting in Boston.

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