Tag Archives: Galaxy

Within ‘Habitable Zone,’ More Planets than We Knew

The number of known places in our galaxy theoretically hospitable to life may be significantly greater than previously thought, according to new research.

Researchers with Planet Hunters are reporting the discovery of a Jupiter-sized planet in the so-called “habitable zone” of a star similar to Earth’s sun, as well as the identification of 15 new candidate planets also orbiting within their star’s habitable zone. (more…)

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Search for Life Suggests Solar Systems More Habitable than Ours

SAN FRANCISCO — Scattered around the Milky Way are stars that resemble our own sun—but a new study is finding that any planets orbiting those stars may very well be hotter and more dynamic than Earth.

That’s because the interiors of any terrestrial planets in these systems are likely warmer than Earth—up to 25 percent warmer, which would make them more geologically active and more likely to retain enough liquid water to support life, at least in its microbial form.

The preliminary finding comes from geologists and astronomers at Ohio State University who have teamed up to search for alien life in a new way. (more…)

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The Helix Nebula: Bigger in Death than Life

A dying star is refusing to go quietly into the night, as seen in this combined infrared and ultraviolet view from NASA’s Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star’s dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.

This object, called the Helix nebula, lies 650 light-years away in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets. (more…)

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First Stars, Galaxies Formed more Rapidly than Expected

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)

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Today in the Milky Way: Cloudy Skies

Adam Block of the UA’s Mount Lemmon SkyCenter brings us a rare view of the clouds wafting through our Milky Way in this Astronomy Picture of the Day.

In silhouette against the Milky Way’s faint starlight, its dusty molecular clouds likely contain raw material to form hundreds of thousands of stars, prompting astronomers to eagerly search the clouds for telltale signs of star birth.

This telescopic close-up looks toward the region at a fragmented Aquila dark cloud complex identified as LDN 673, stretching across a field of view slightly wider than the full moon.

For this image selected by NASA as the June 29 Astronomy Picture of the Day, astrophotographer Adam Block of the University of Arizona’s Mount Lemmon SkyCenter remotely operated the 32-inch Schulmann Telescope to peer into the vast chasms of gas and dust wafting through the Milky Way, exposing for about 15 minutes at a time during several nights in April and May. (more…)

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Black Hole Caught Red-Handed in a Stellar Homicide

PASADENA, Calif. – Astronomers have gathered the most direct evidence yet of a supermassive black hole shredding a star that wandered too close. NASA’s Galaxy Evolution Explorer, a space-based observatory, and the Pan-STARRS1 telescope on the summit of Haleakala in Hawaii were among the first to help identify the stellar remains.

Supermassive black holes, weighing millions to billions times more than the sun, lurk in the centers of most galaxies. These hefty monsters lie quietly until an unsuspecting victim, such as a star, wanders close enough to get ripped apart by their powerful gravitational clutches. (more…)

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NASA’s Spitzer Finds Galaxy with Split Personality

PASADENA, Calif. — While some galaxies are rotund and others are slender disks like our spiral Milky Way, new observations from NASA’s Spitzer Space Telescope show that the Sombrero galaxy is both. The galaxy, which is a round elliptical galaxy with a thin disk embedded inside, is one of the first known to exhibit characteristics of the two different types. The findings will lead to a better understanding of galaxy evolution, a topic still poorly understood.

“The Sombrero is more complex than previously thought,” said Dimitri Gadotti of the European Southern Observatory in Chile and lead author of a new paper on the findings appearing in the Monthly Notices of the Royal Astronomical Society. “The only way to understand all we know about this galaxy is to think of it as two galaxies, one inside the other.” (more…)

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Clocking an Accelerating Universe: First Results from BOSS

Berkeley Lab scientists are the leaders of BOSS, the Baryon Oscillation Spectroscopic Survey. They and their colleagues in the third Sloan Digital Sky Survey have announced the most precise measurements ever made of the era when dark energy turned on.

Some six billion light years distant, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction of all the matter it contained, the universe had been expanding ever more slowly. Then, as matter spread out and its density decreased, dark energy took over and expansion began to accelerate.

Today BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on. (more…)

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