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Author Topic: NEWS ON SPACE AND OUR PLANETARY SYSTEM  (Read 1147 times)
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« Reply #75 on: Today at 05:37 AM »

July 31, 2015

Brightest aurora ever discovered in outer space

by Emily Bills
Red Orbit

If you think the aurora on Earth is amazing, check this out: astronomers have discovered the first auroras ever seen outside of our solar system, and they’re 1 million times brighter than any aurora witnessed on Earth.

What are auroras?

Those colorful streaks of light you see streaming in the northern or southern skies are called auroras, and guess what? You can see auroras on all the other planets with a magnetic field. Auroras are caused by currents in the magnetosphere, sending down electrons that mix with other molecules to create the brilliant displays.

We had no idea auroras appeared on planets outside of our solar system – until now.

Brown dwarf star shows telltale aurora signs

According to Space.com, astronomers checked out a super mysterious Jupiter-sized object called LSR J1835+3259 located outside our solar system in their quest for these ‘alien’ auroras. These astronomers said it’s too heavy to be a planet and too light to be a star, so they suggested it’s a brown dwarf.

In 2008, scientists discovered that LSR J1835+3259 actually emitted radio waves in spurts and were surprised, because radio waves usually come from aurorae in our solar system. Could this be? Scientists had to investigate, so they used the Karl G. Jansky Very Large Array in New Mexico to scan radio wavelengths of light, as well as the Hale Telescope in California and the W. M. Keck Observatory in Hawaii to measure visual wavelengths and found signs of auroras.

According to the lead author of the study, Gregg Hallinan, the auroras that would be seen on this brown dwarf would be red – unlike the blues and greens we see here on Earth. The auroras would also possibly be 1 million times brighter than any aurora seen on Earth, and 200 times brighter than auroras on Jupiter, the planet with the brightest known auroras.

While it’s unknown how LSR J1835+3259’s auroras form at this time, Hallinan and his team have developed a telescope, the Owens Valley Long Wavelength Array, to detect these far-off, super bright auroras. He theorizes that electrically charged particles could rain down from dust onto the planet, or that an Earth-sized planet could be generating the auroras as it zooms through its magnetic field.

Either way, Hallinan is excited by the results so far from his telescope: "We've already confirmed aurorae for a few more objects," Hallinan said. "Maybe 10 percent or higher of brown dwarfs may exhibit aurorae."


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« Reply #76 on: Today at 05:52 AM »

CS Monitor

NASA's discovery of closest super-Earth is a 'kind of Rosetta Stone'

Using NASA's Spitzer telescope astronomers confirm the discovery of the nearest rocky planet outside our solar system, larger than Earth and a 'gold mine' for researchers.

By Kelsey Warner, Staff July 31, 2015

NASA did not take a vacation this July, closing out a busy month by confirming the discovery of the nearest rocky planet outside our solar system.

Larger than Earth and at "a mere" 21 light years away, the exoplanet - so-called because it orbits a star other than the Sun - offers a unique opportunity for research, according to NASA scientists, because it is so close. Most known planets are hundreds of light years away. 

Named HD 219134b, the exoplanet orbits too close to its star to sustain life, and cannot be seen directly, even by telescopes, but the star it orbits is visible to the naked eye in dark skies in the Cassiopeia constellation, near the North Star. The rocky planet was first detected by a telescope instrument on the Canary Islands called HARPS-North, which measured the planet's mass and orbit by the gravitational “tug” it exerts on the star it orbits. The planet was determined to have a mass 4.5 times that of Earth, and a “speedy” three-day orbit around its star, according to NASA.
Recommended: What makes a planet livable? Five things scientists look for.

Spitzer, a space telescope that detects heat radiation, followed up on the initial data, and discovered the planet transits its star. The planet's size is about 1.6 times that of Earth, according to Spitzer’s measurements. Combining the size and the mass picked up by HARPS-North, scientists determined a density of 3.5 ounces per cubic inch, which makes HD 219134b a rocky planet.
What makes a planet livable? Five things scientists look for.

Rocky planets that are bigger than Earth, like the one just discovered, belong to a growing class of planets termed super-Earths, according to NASA.

"Thanks to NASA's Kepler mission, we know super-Earths are ubiquitous in our galaxy, but we still know very little about them," said co-author Michael Gillon of the University of Liege in Belgium, lead scientist for the Spitzer detection of the transit, in a statement. "Now we have a local specimen to study in greater detail. It can be considered a kind of Rosetta Stone for the study of super-Earths."

The conclusion that our closest rocky neighbor crosses its star has NASA anticipating a scramble to find out as much as possible from the ground and space. Only a small fraction of exoplanets can be detected transiting their stars due to their relative orientation to Earth. When the orientation is just right, the planet’s orbit places it between its star and Earth, dimming the detectable light of its star. As the planet passes before its star, researchers can tease chemical data out of the dimming starlight that results. If the planet is determined to have an atmosphere, chemicals in it can imprint patterns in the observed starlight, according to NASA.

"Transiting exoplanets are worth their weight in gold because they can be extensively characterized," said Michael Werner, the project scientist for the Spitzer mission at NASA's Jet Propulsion Laboratory, in a statement. "This exoplanet will be one of the most studied for decades to come."


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