all high energy astrophysics stories

Building a stellar time machine

50443248 — Mon, 06 Jul 2009 13:47:38 -0400

Harvard researchers are building a celestial time machine that lets astronomers look back at hundreds of thousands of objects in the Earth’s skies over the past century.

The effort aims to digitize 525,000 glass photographic plates taken at observing sites around the world between the 1880s and the 1980s. The collection, the largest such in the world, contains a treasure trove of largely unexamined data, according to Paine Professor of Practical Astronomy Jonathan Grindlay, who is leading the digitizing effort.

Visitors will gravitate to 'Black Holes' exhibit

50443248 — Thu, 18 Jun 2009 09:27:12 -0400

On Sunday, June 21, a new exhibit developed by educators and scientists at the Harvard-Smithsonian Center for Astrophysics (CfA) will open at the Boston Museum of Science.

Peculiar, junior-sized supernova discovered by New York teen

50443248 — Mon, 15 Jun 2009 15:20:44 -0400

In November 2008, Caroline Moore, a 14-year-old student from upstate New York, discovered a supernova in a nearby galaxy, making her the youngest person ever to do so. Additional observations determined that the object, called SN 2008ha, is a new type of stellar explosion, 1,000 times more powerful than a nova but 1,000 times less powerful than a supernova. Astronomers say that it may be the weakest supernova ever seen.

Looking for subatomic insights in Minnesota

50443248 — Mon, 18 May 2009 14:00:14 -0400

After years of planning, officials broke ground this month for a new high-energy physics experiment that will probe the behavior of one of the basic particles that make up the universe: the neutrino.

Charbonneau gets prestigious ‘young researcher’ award

50443248 — Wed, 04 Mar 2009 12:59:36 -0500

David Charbonneau, the 34-year-old Thomas D. Cabot Associate Professor of Astronomy, has been named the recipient of the National Science Foundation’s 2009 Alan T. Waterman Award, and will receive $500,000 over a three-year period for scientific research or advanced study in his field.

ATLAS detector seeks to illuminate universe’s mysteries

404132862 — Wed, 10 Sep 2008 11:37:28 -0400

Scientists at Harvard and around the world held their breath earlier today, as colleagues switched on the most powerful particle accelerator ever built, the Large Hadron Collider at CERN, the particle physics laboratory in Geneva.

'Wintering-over' at the South Pole

70652986 — Mon, 26 Mar 2007 06:26:25 -0400

They came to the South Pole, enduring months of bitter cold, darkness, and isolation, to peer at the galaxy's center through clear, dry skies. And in December, they - scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) - declared "mission accomplished."

After 11 years, the Antarctic Submillimeter Telescope and Remote Observatory, AST/RO, was dismantled last fall. The 1.7- meter telescope was boxed up for transport and now sits on the snow, awaiting a decision on its next stop.

Taking a CAT scan of the early universe

70652986 — Mon, 26 Mar 2007 05:36:09 -0400

Reporting in the Nov. 11, 2004, issue of Nature, astrophysicists J. Stuart B. Wyithe (University of Melbourne) and Abraham Loeb (Harvard-Smithsonian Center for Astrophysics) have calculated the size of cosmic structures that will be measured when astronomers effectively take CAT scan-like images of the early universe. Those measurements will show how the universe evolved over its first billion years of existence. "Until now, we've been limited to a single snapshot of the universe's childhood -- the cosmic microwave background," says Loeb. "This new technique will let us view an entire album full of the universe's baby photos. We can watch the universe grow up and mature." The heart of the tomography technique described by Wyithe and Loeb is the study of 21-centimeter-wavelength radiation from neutral hydrogen atoms. In our own galaxy, this radiation has helped astronomers to map the Milky Way's spherical halo. To map the distant young universe, astronomers must detect 21-cm radiation that has been redshifted: stretched to longer wavelengths (and lower frequencies) by the expansion of space itself. "Tomography is a complicated process, which is one reason why it hasn't been done before at very high redshifts," says Wyithe. "But it's also very promising because it's one of the few techniques that will let us study the first billion years of the universe's history."

Young star caught speeding

70652986 — Mon, 26 Mar 2007 05:34:51 -0400

Findings linking a speeding star to its birthplace provide direct observational support of theoretical simulations predicting that protostars can be tossed out of a young cluster. This is the first time that such a fast-moving young star has been seen outside of a cluster or binary system. Astronomers Alyssa Goodman (Harvard-Smithsonian Center for Astrophysics) and Héctor Arce (Caltech) announced Jan. 5, 2004 at the 203rd meeting of the American Astronomical Society that they have caught a newly formed star in the act of speeding. PV Ceph, located about 1,400 light years away in the constellation Cepheus, is whizzing through space at a speed of 40,000 miles per hour-some 40 times faster than a speeding bullet. And like a bullet, it left an exit wound when it ripped out of the star cluster where it formed. The discovery has significant implications for calculations of star formation efficiency -- how many stars of what sizes are likely to form from a given molecular cloud. Modeling that process correctly is critical to understanding how galaxies everywhere turn gas into stars.

Astronomers link gamma-ray bursts, supernovae

70652986 — Mon, 26 Mar 2007 05:29:44 -0400

Gamma-ray bursts are incredibly bright flashes of high-energy radiation that likely signal the birth of black holes. Bursts occur at random locations scattered across the sky, and few last more than a minute, making them a challenge to study. A supernova is the explosion of a star at least eight times as massive as the Sun. When such stars deplete their nuclear fuel, they no longer have the energy to support their mass. Their cores implode, forming either a neutron star or (if there is enough mass) a black hole. Could the two be related? Astronomers didn't know for sure until a recent investigation uncovered the connection. "There should no longer be doubt in anybody's mind that gamma-ray bursts and supernovae are connected," said Thomas Matheson of the Harvard-Smithsonian Center for Astrophysics, a member of the team that made this discovery. The investigation began on March 29, 2003, when NASA's High-Energy Transient Explorer satellite discovered one of the brightest and closest gamma-ray bursts on record. Located in the constellation Leo, the 30-second burst outshone the entire Universe in gamma rays, and its optical afterglow was still over a trillion times brighter than the Sun two hours later. Through observations of that afterglow on subsequent nights, astronomers spotted the telltale signs of a supernova. The team cannot yet determine the timing of the burst relative to the supernova (whether one preceded the other or whether both began at the same time), but the same event - a star explosion - was certainly the trigger for both.

X-ray arcs tell tale of giant eruption

70652986 — Mon, 26 Mar 2007 05:25:27 -0400

Scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) report that two arc-like structures of multimillion-degree gas in the galaxy Centaurus A appear to be part of a ring 25,000 light years in diameter. The size and location of the ring suggest that it could have been produced in a titanic explosion that occurred about 10 million years ago. A composite image of the galaxy made with radio (red and green), optical (yellow-orange), and X-ray data (blue) presents a stunning tableau of a tumultuous galaxy. A broad band of dust and cold gas is bisected at an angle by opposing jets of high-energy particles blasting away from the supermassive black hole in the nucleus. Lying in a plane perpendicular to the jets are the two large arcs of X-ray emitting hot gas.

Astronomers take the measure of dark matter in the universe

70652986 — Mon, 26 Mar 2007 05:15:32 -0400

Astronomers believe that most of the matter in the universe is invisible to us -- so called "dark matter." The nature of this dark matter is not known, but most astronomers think that it is in the form of an as-yet-unknown type of elementary particle that contributes to gravity through its mass but otherwise interacts weakly with normal matter. These dark matter particles are often called WIMPs, an acronym for "weakly interacting massive particles." Using the Chandra X-ray Observatory, a research team observed five galaxy clusters to determine how much dark matter they contain. Galaxy clusters are vast concentrations of galaxies, hot gas and dark matter spanning millions of light years, held together by gravity.

Young pulsar reveals clues to supernova

70652986 — Mon, 26 Mar 2007 05:15:39 -0400

Using the Chandra X-ray Observatory to learn more about pulsars, A team led by Stephen Murray of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., studied 3C58, the remains of a supernova observed on Earth in 1181 AD in the constellation Cassiopeia. 3C58 is one of the youngest known pulsars, and behaves quite differently from the better known pulsar in the Crab Nebula, which is about the same age. The observations of 3C58 will enable scientists to better understand how neutron stars are formed in the seconds just before a supernova explosion, and how they pump energy into the space around them for thousands of years after the explosion. 3C58 is a neutron star rotating 15 times a second, which means it is rotating at about half the rate of the Crab Nebula pulsar.

Astronomers detect dust disks around very young brown dwarfs in the Orion Nebula

70652986 — Mon, 26 Mar 2007 05:13:37 -0400

The results of recent observations by an international team of astronomers suggest that brown dwarfs share a common origin with stars. Brown dwarfs are more similar in nature to stars than to planets and, like stars, have the potential to form with accompanying systems of planets. The observation by the researchers of dusty protoplanetary disks around the faintest objects in the Orion Nebula cluster confirms both the membership of these faint stars in the cluster and their nature as bona fide substellar objects, making this the largest population of brown dwarf objects yet known.

Star factory near galactic center bathed in high-energy X-rays

70652986 — Mon, 26 Mar 2007 05:13:41 -0400

A team of astronomers, including some from the Harvard-Smithsonian Center for Astrophysics, has looked into the core of our own Milky Way galaxy and discovered a new phenomenon. The "cauldron" of 60-million-degree gas surrounding a group of young stars in the Arches Cluster supports earlier theoretical predictions about what happens when solar winds from massive stars collide with each other: they form very hot gas and generate X-rays. The discovery was made by a research team headed by Professor Farhad Zadeh of Northwestern University. The team used NASA's Chandra X-ray Observatory to make its observations. Massive stars, newborn stars, and stellar winds have long been known to emit X-rays.