all astronomy stories

Laser precision added to search for new Earths

404132862 — Wed, 02 Apr 2008 14:46:48 -0400

Harvard scientists have unveiled a new laser-measuring device that they say will provide a critical advance in the resolution of current planet-finding techniques, making the discovery of Earth-sized planets possible.

The discovery of planets outside of our solar system, called “exoplanets,” is one of the hottest fields in astronomy and holds great promise to increase our understanding of Earth’s solar system and of how life first took hold on this planet.

Sulfur dioxide may have helped maintain a warm early Mars

404132862 — Thu, 20 Dec 2007 12:56:35 -0500

Sulfur dioxide (SO2) may have played a key role in the climate and geochemistry of early Mars, geoscientists at Harvard University and the Massachusetts Institute of Technology (MIT) suggest in the Dec. 21 issue of the journal Science. Their hypothesis may resolve longstanding questions about evidence that the climate of the Red Planet was once much warmer than it is today.

White dwarf "sibling rivalry" explodes

404132862 — Thu, 01 Nov 2007 15:57:02 -0400

Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that a supernova discovered last year was caused by two colliding white dwarf stars. The white dwarfs were siblings orbiting each other. They slowly spiraled inward until they merged, touching off a titanic explosion. CfA observations show the strongest evidence yet of what was, until now, a purely theoretical mechanism for creating a supernova.

Mystery comet explodes into brightness

404132862 — Thu, 25 Oct 2007 20:37:19 -0400

A once-faint comet has made a sudden leap from obscurity to
center stage.

Comet 17P Holmes, now visible to northern hemisphere
residents, increased its brightness by a factor of one million this week,
going from magnitude 17 to 2. This makes it visible to the unaided eye as
well as binoculars and telescopes, offering a unique viewing opportunity for
sky watchers.

Harvard brings the Earth to high school

jake — Mon, 22 Oct 2007 13:16:26 -0400

Steam vents in Yellowstone National Park are part of the area’s unique environment, seen in a case study exploring Yellowstone and the reintroduction of wolves into the park. This case study is part of a new environmental science course for high school science teachers.

Harvard scientists and media specialists unveiled an online environmental science course Monday (Oct. 1) aimed at high school teachers and, through them, high school students — the future inheritors of the Earth’s environmental problems.

The course, called “The Habitable Planet: A Systems Approach to Environmental Science,” features a scientific “dream team” of experts from Harvard and elsewhere who describe their fields, relevant problems, and potential solutions in a series of online videos.

Harvard astronomers share dark prize

50443248 — Tue, 02 Oct 2007 10:02:27 -0400

Two teams who upset everyone's ideas about how the universe works and its future will share the $500,000 Gruber Cosmology Prize for discovering that 70 percent of the universe is nothing but a strange form of energy.

In 1998, a group called the High-z Supernova Search Team published irresistible evidence that the universe is expanding at a rate that may never slow down. Eleven of the 19 members of the High-z team are or were affiliated with Harvard University. Months later, a second team, the Supernova Cosmology Project, independently confirmed the startling finding. That team was lead by Saul Perlmutter of the University of California, Berkeley.

Oceans are back on Mars

Mon, 09 Jul 2007 13:40:25 -0400

Since spacecraft sent back the first close-up images of Mars more than 30 years ago, some experts have insisted that oceans once existed on the now dry, cold planet. Critics have maintained for decades that such an idea is the product of unrestrained imaginations. Now, a study published in the June 14 issue of the British journal Nature reports new evidence that our neighbor in space once boasted an ocean or oceans as big, relative to planet size, as the Atlantic on Earth. "We were able to lay to rest one of the main objections to the idea that there once were oceans on Mars," says Taylor Perron, a postdoctoral fellow in Harvard's Department of Earth and Planetary Sciences.

Astronomers nab culprit in galactic hit-and-run

70652986 — Mon, 26 Mar 2007 05:46:46 -0400

The Andromeda galaxy, the closest large spiral to the Milky Way, appears calm and tranquil as it wheels through space. But appearances can be deceiving. Astronomers have new evidence that Andromeda was involved in a violent head-on collision with the neighboring dwarf galaxy Messier 32 (M32) more than 200 million years ago.

"Like a CSI team, we gathered clues and reconstructed the scene of the crime," said Pauline Barmby (Harvard-Smithsonian Center for Astrophysics), a member of the research group that made the discovery. "The evidence clearly shows that M32 is guilty of committing a hit-and-run."

This discovery was reported in the Oct. 19, 2006, issue of the journal Nature.

Dramatic proof of the galactic smash-up came from images taken by the Infrared Array Camera (IRAC) on NASA's Spitzer Space Telescope. Those images revealed a never-before-seen dust ring deep within the Andromeda galaxy. When combined with a previously observed outer ring, the presence of both dust rings suggests a long-ago disturbance whose effects are still expanding outward through Andromeda.

Innovative computing initiative sets sights on projects

Thu, 12 Jul 2007 11:05:49 -0400

After a year of hiring, moving into new digs, and generally getting its feet wet, the Harvard Initiative in Innovative Computing (IIC) is ready to forge ahead into the new year, diving into computer-intensive projects that need not just computational firepower, but also innovative thinking.

The initiative is moving ahead on a half-dozen or so projects generated by groups of Harvard faculty in response to a call for ideas last spring. These projects span a broad array of disciplines, from using medical imaging technology to illuminate star creation to producing astonishingly detailed pictures of the mammalian brain to designing a Web portal that offers astronomers new ways to share data.

Strange new planet baffles astronomers

70652986 — Mon, 26 Mar 2007 06:28:15 -0400

Using a network of small automated telescopes known as HAT, Smithsonian astronomers have discovered a planet unlike any other known world. This new planet, designated HAT-P-1, orbits one member of a pair of distant stars 450 light-years away in the constellation Lacerta.

"We could be looking at an entirely new class of planets," said Gaspar Bakos, a Hubble fellow at the Harvard-Smithsonian Center for Astrophysics (CfA). Bakos designed and built the HAT network and is lead author of a paper submitted to the Astrophysical Journal describing the discovery. That paper is available online at http://arxiv.org/abs/astro-ph/0609369.

With a radius about 1.38 times Jupiter's, HAT-P-1 is the largest known planet. In spite of its huge size, its mass is only half that of Jupiter.

"This planet is about one-quarter the density of water," Bakos said. "In other words, it's lighter than a giant ball of cork! Just like Saturn, it would float in a bathtub if you could find a tub big enough to hold it, but it would float almost three times higher."

HAT-P-1 revolves around its host star every 4.5 days in an orbit one-twentieth of the distance from Earth to the Sun. Once each orbit, it passes in front of its parent star, causing the star to appear fainter by about 1.5 percent for more than two hours, after which the star returns to its previous brightness.

HAT-P-1's parent star is one member of a double-star system called ADS 16402 and is visible in binoculars. The two stars are separated by about 1500 times the Earth-Sun distance. The stars are similar to the Sun but slightly younger - about 3.6 billion years old compared to the Sun's age of 4.5 billion years.

Major funding for HATnet was provided by NASA.

Cosmic blast announces a future supernova

Thu, 12 Jul 2007 16:07:54 -0400

It's one thing to theorize about an exploding star the size of our sun, it's another to look up in the sky and watch one getting ready to blow.

Astronomers are now doing this.

On Feb. 12, a star known as RS Ophiuchi, some 8,000 trillion miles away, erupted in an explosion so bright it could be seen on Earth without a telescope. It was the star's sixth attention-getting blowout since 1898.

Using satellites and ground-based telescopes, observers from the Harvard-Smithsonian Center for Astrophysics (CfA) and their colleagues from other institutions caught the eruption near its maximum brightness. They measured high-energy X-rays, low-energy radio waves, and heat coming from the outburst.

Jupiter's 'big brother' has moon-forming dust disk

70652986 — Mon, 26 Mar 2007 06:27:45 -0400

Earth's moon was created by an early collision with another large planetary body. It was a "chip off the old block." Mars captured its asteroidal moons as they passed by. But Jupiter made its own moons out of dust and gas remaining from its formation. Now, observations by astronomer Subhanjoy Mohanty of the Harvard- Smithsonian Center for Astrophysics and his colleagues provide the first direct evidence for a dusty disk around a distant planet that in mass would be Jupiter's "big brother."

"It is quite possible that moons or moonlets could form out of this disk, just as they have around the giant planets in our own solar system," said Mohanty.

Mohanty presented the discovery June 5, 2006, in a press conference at the 208th meeting of the American Astronomical Society. Other members of the team are Ray Jayawardhana (University of Toronto), Nuria Huélamo (ESO) and Eric Mamajek (CfA).

The team studied a planetary mass object known as 2MASS1207-3932B, which is located about 170 light-years from Earth in the direction of the constellation Centaurus. 2M1207B, as it is abbreviated, orbits a tiny brown dwarf star at a separation of about 40 astronomical units, or 3.7 billion miles - comparable to the size of Pluto's orbit. That separation is much larger than typical for binary brown dwarf systems. The wide separation may indicate that the duo formed in relative isolation, far from passing stars that could have pulled them apart.

'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.

Super-Earths may be three times more common than Jupiters

70652986 — Mon, 26 Mar 2007 06:25:36 -0400

Astronomers have discovered a new "super-Earth" orbiting a red dwarf star located about 9,000 light-years away. This newfound world weighs about 13 times the mass of the Earth and is probably a mixture of rock and ice, with a diameter several times that of Earth. It orbits its star at about the distance of the asteroid belt in our solar system, 250 million miles out. Its distant location chills it to -330 degrees Fahrenheit, suggesting that although this world is similar in structure to the Earth, it is too cold for liquid water or life.

Orbiting almost as far out as Jupiter does in our solar system, this "super-Earth" likely never accumulated enough gas to grow to giant proportions. Instead, the disk of material from which it formed dissipated, starving it of the raw materials it needed to thrive.

"This is a solar system that ran out of gas," says Harvard astronomer Scott Gaudi of the Harvard-Smithsonian Center for Astrophysics (CfA), a member of the MicroFUN collaboration that spotted the planet.

The discovery was reported March 13, 2006 in a paper posted online at http://arxiv.org/abs/astro-ph/0603276 and submitted to The Astrophysical Journal Letters for publication.

Neutron star swaps lead to short gamma-ray bursts

70652986 — Mon, 26 Mar 2007 06:24:31 -0400

Gamma-ray bursts are the most powerful explosions in the universe, emitting huge amounts of high-energy radiation. For decades their origin was a mystery. Scientists now believe they understand the processes that produce gamma-ray bursts. However, a new study by Jonathan Grindlay of the Harvard- Smithsonian Center for Astrophysics (CfA) and his colleagues, Simon Portegies Zwart (Astronomical Institute, The Netherlands) and Stephen McMillan (Drexel University), suggests a previously overlooked source for some gamma-ray bursts: stellar encounters within globular clusters.

"As many as one-third of all short gamma-ray bursts that we observe may come from merging neutron stars in globular clusters," said Grindlay.

Gamma-ray bursts (GRBs) come in two distinct "flavors." Some last up to a minute, or even longer. Astronomers believe those long GRBs are generated when a massive star explodes in a hypernova. Other bursts last for only a fraction of a second. Astronomers theorize that short GRBs originate from the collision of two neutrons stars, or a neutron star and a black hole.

Most double neutron star systems result from the evolution of two massive stars already orbiting each other. The natural aging process will cause both to become neutron stars (if they start with a given mass), which then spiral together over millions or billions of years until they merge and release a gamma-ray burst.

Grindlay's research points to another potential source of short GRBs - globular clusters. Globular clusters contain some of the oldest stars in the universe crammed into a tight space only a few light-years across. Such tight quarters provoke many close stellar encounters, some of which lead to star swaps. If a neutron star with a stellar companion (such as a white dwarf or main-sequence star) exchanges its partner with another neutron star, the resulting pair of neutron stars will eventually spiral together and collide explosively, creating a gamma-ray burst.

The paper announcing this finding was published in the Jan. 29, 2006 online issue of Nature Physics. It is available online at http: //www.nature.com/nphys/index.html and in preprint form at http://arxiv.org/abs/astro-ph/0512654.