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NASA’s LADEE Spacecraft Gets Final Science Instrument Installed

October 26, 2012 Leave a comment

Engineers at NASA’s Ames Research Center, Moffett Field, Calif., have installed the third and final science instrument that will fly onboard NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE).

LADEE is a robotic mission that will orbit the moon to gather detailed information about the lunar atmosphere, conditions near the surface and environmental influences on lunar dust.

“The installation of the final science instrument to LADEE’s flight structure in the clean room at Ames is an important step toward completing the spacecraft build and testing,” said Butler Hine, LADEE project manager at Ames. “Now that the three science instruments are fully integrated onto the spacecraft, it has become a full-fledged, high-precision space observatory.”

Full Story: http://www.nasa.gov/centers/ames/news/releases/2012/12-76AR.html

For The Milky Way, It’s Snack Time

October 26, 2012 Leave a comment

Yale astronomers have caught the Milky Way having a snack.

Using the Sloan Digital Sky Survey, researchers have discovered a band, or stream, of stars believed to be the remnant of an ancient star cluster slowly being ingested by the Milky Way, Earth’s home galaxy.

“The Milky Way is constantly gobbling up small galaxies and star clusters,” said Ana Bonaca, a Yale graduate student and lead author of a study forthcoming in Astrophysical Journal Letters. “The more powerful gravity of our Milky Way pulls these objects apart and their stars then become part of the Milky Way itself.”

Researchers have previously found evidence of the Milky Way eating up dwarf galaxies. Bonaca argues that the newly found stellar stream is the remnant of a star cluster rather than of a larger galaxy, because the stream is very narrow.”Our discovery is more of a light snack than a big meal for the Milky Way,” says Marla Geha, associate professor of astronomy at Yale and a co-author of the study. “Studying this digestion process in detail is important because it gives us new insight into how all galaxies form and evolve.”

Full Story: http://news.yale.edu/2012/10/25/milky-way-it-s-snack-time

New Study Brings A Doubted Exoplanet ‘Back From The Dead’

October 26, 2012 Leave a comment

Artist’s impression of the exoplanet, Fomalhaut b, orbiting its sun, Fomalhaut. Credit: ESA; Hubble, M. Kornmesser; and ESO, L. Calçada and L. L. Christensen

A second look at data from NASA’s Hubble Space Telescope is reanimating the claim that the nearby star Fomalhaut hosts a massive exoplanet. The study suggests that the planet, named Fomalhaut b, is a rare and possibly unique object that is completely shrouded by dust.

In November 2008, Hubble astronomers announced the exoplanet, named Fomalhaut b, as the first one ever directly imaged in visible light around another star. The object was imaged just inside a vast ring of debris surrounding but offset from the host star. The planet’s location and mass — no more than three times Jupiter’s — seemed just right for its gravity to explain the ring’s appearance.

Recent studies have claimed that this planetary interpretation is incorrect. A new analysis, however, brings the planet conclusion back to life.

“Although our results seriously challenge the original discovery paper, they do so in a way that actually makes the object’s interpretation much cleaner and leaves intact the core conclusion, that Fomalhaut b is indeed a massive planet,” said Thayne Currie, an astronomer formerly at NASA’s Goddard Space Flight Center in Greenbelt, Md., and now at the University of Toronto.

Full Story: http://www.nasa.gov/mission_pages/hubble/science/fomalhaut-exo.html

The White Widow Model: A New Scenario For The Birth Of Type Ia Supernovae

October 26, 2012 Leave a comment

Supernova remnant 0509-67.5 was searched for a left-behind partner star without success. Image Credit: NASA, ESA, CXC, SAO, the Hubble Heritage Team (STScI/AURA), and J. Hughes (Rutgers University)

J. Craig Wheeler has studied the exploding stars called supernovae for more than four decades. Now he has a new idea on the identity of the “parents” of one of the most important types of supernovae — the Type Ia, those used as “standard candles” in cosmology studies that led to the discovery of dark energy, the mysterious force causing the universe’s expansion to speed up.

Wheeler lays out his case for supernova parentage in the current issue of The Astrophysical Journal. He explains why he thinks the parents of Type Ia could be a binary star made up of white dwarf star (the burnt-out remnant of a Sun-like star) and a particular type of small star called an “M dwarf.”

In the paper, he explains that current theories for Type Ia parents don’t correctly match up with telescope data on actual supernovae.

Full Story: http://mcdonaldobservatory.org/news/releases/2012/1025.html

Monster Galaxy May Have Been Stirred Up By Black-Hole Mischief

October 26, 2012 Leave a comment

Giant elliptical galaxy in the center of this image, taken by NASA’s Hubble Space Telescope. Credit: NASA, ESA, M. Postman (STScI), T. Lauer (NOAO), and the CLASH team

Astronomers using NASA’s Hubble Space Telescope have obtained a remarkable new view of a whopper of an elliptical galaxy that may have been puffed up by the actions of one or more black holes in its core.

Spanning a little more than one million light-years, the galaxy is about 10 times the diameter of our Milky Way galaxy. The bloated galaxy is a member of an unusual class of galaxies with a diffuse core filled with a fog of starlight where there would normally be a concentrated peak of light around a central black hole. Viewing the core is like seeing a city with no downtown, just houses sprinkled across a vast landscape.

Astronomers used Hubble’s Advanced Camera for Surveys and Wide Field Camera 3 to measure the amount of starlight across the galaxy, dubbed A2261-BCG. The Hubble observations revealed that the galaxy’s puffy core, measuring about 10,000 light-years, is the largest yet seen.

Astronomers have proposed two possibilities for the puffy core. One scenario is that a pair of merging black holes gravitationally stirred up and scattered the stars. Another idea is that the merging black holes were ejected from the core. Left without an anchor, the stars began spreading out even more, creating the puffy-looking core.

Full Story: http://hubblesite.org/newscenter/archive/releases/2012/24/full/
Also: http://www.spacetelescope.org/news/heic1216/

After-Effects Of Saturn’s Super Storm Shine On

October 26, 2012 Leave a comment

Saturn’s giant storm, as seen at visible wavelengths during much of 2011. Credits: NASA/JPL-Caltech/Space Science Institute

The heat-seeking capabilities of the international Cassini spacecraft and two ground-based telescopes have provided the first look at the aftermath of Saturn’s ‘Great Springtime Storm’. Concealed from the naked eye, a giant oval vortex is persisting long after the visible effects of the storm subsided.

But in new reports that focus on the temperatures, winds and composition of Saturn’s atmosphere, scientists find that the spectacular cloud displays were only part of the story. Much of the associated activity took place beyond the reach of visible-light cameras, and the after-effects are still continuing today.

“It’s extremely unusual, as we can only see the vortex at infrared wavelengths – we can’t tell that it is there simply by looking at the cloud cover.”

Full story: http://www.esa.int/esaSC/SEMLPIMFL8H_index_1.html
Also: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50994
Also: http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20121025.html

A Black Widow’s Tango Mortale In Gamma-Ray Light

October 26, 2012 Leave a comment

Pulsars are the compact remnants from explosions of massive stars. Some of them spin around their own axis hundreds of times per second, emitting beams of radiation into space. Until now, they could only be found through their pulsed radio emissions. Now, scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Hanover assisted by the Max Planck Institute for Radio Astronomy have discovered a millisecond pulsar solely via its pulsed gamma radiation. A new data analysis method developed by the AEI was crucial for the success. The pulsar is accompanied by an unusual sub-stellar partner, which it is vaporizing, hence the name “black widow”.

To unambiguously identify a gamma-ray pulsar, astronomers must know its properties to very high precision. This includes its position, spin frequency, and how the latter changes over time. If the pulsar is in a binary system, the analysis problem is even more complicated: at least three additional orbital parameters have to be determined as well.

“We developed a particularly efficient method to search the data from NASA’s Fermi satellite for gamma-ray millisecond pulsars, including those in binary systems. Only this method enabled us to probe the wide parameter ranges,” says Holger Pletsch, lead author of the article published in Science. The new analysis method enables scientists to conduct a ‘blind search’ for gamma-ray millisecond pulsars for the first time – right up to very high spinning frequencies.

Full Story: http://www.mpg.de/6598331/gamma-pulsar