NASA astronomers discover Sun's star-neighbor icy 'as Earth's North Pole'

NASA astronomers discover Sun's star-neighbor icy 'as Earth's North Pole'
© Photo: en.wikipedia.org/Pethrus/cc-by-sa 3.0

NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescope have discovered a new neighbour to the Earth - a "brown dwarf," which is as cold as earth's North Pole. Images from the space telescopes also pinpointed the object is just 7.2 light years away, making it the fourth closest system to our Sun.

"It is very exciting to discover a new neighbor of our solar system that is so close," posited Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State, in a statement. "In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight.
The newfound coldest brown dwarf, named WISE J085510.83—071442.5, has a chilly temperature between minus 48 to minus 13 degrees Celsius.
Previous record holders for coldest brown dwarfs were about room temperature.
Although it is very close to our solar system, WISE J085510.83—071442.5 is not an appealing destination for human space travel in the distant future, researchers said.
"Any planets that might orbit it would be much too cold to support life as we know it," Luhman said.
NASA points out that brown dwarf is estimated to be 3 to 10 times the mass of Jupiter. With such a low mass, it could be a gas giant similar to Jupiter that was ejected from its star system. But scientists estimate it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common. In case of that, it is one of the least massive brown dwarfs known.
Astronomers knew the object was close to our Sun because the "[it] appeared to move really fast in the WISE data." According to Luhman, the closer a body, the more it appears to move in photos snapped months apart.
"This object appeared to move really fast in the WISE data. That told us it was something special," said Luhman.
WISE was able to detect the brown star as it observed the entire sky twice in infrared light. Being cool objects, brown dwarfs may be invisible when viewed by visible-light telescopes, but their thermal glow stands out in infrared light.
Read more: http://voiceofrussia.com/news/2014_04_27/NASA-astronomers-discover-Suns-star-neighbor-icy-as-Earths-North-Pole-7322/

List of nearest stars and brown dwarfs - Wikipedia, the free ...

en.wikipedia.org/wiki/List_of_nearest_stars‎
Besides the Sun, only three are first-magnitude stars: Alpha Centauri, Sirius, ...... solar neighborhood IV: discovery of the twentieth nearest star, Todd J. Henry, ...
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an effective treatment alternative for severe epilepsy

Scientists have built an ‘off switch’ for the brain

Heather Saul,The Independent | Apr 27, 2014, 12.30 PM IST
READ MORE Thomas Insel|optogenetic protein|National Institute of Mental Health|Karl Deisseroth
Scientists have built an ‘off switch’ for the brain
Now, after almost a decade of research, scientists have been able to shut down the neurons as well as activate them.
LONDON: Scientists have developed an "off-switch" for the brain to effectively shut down neural activity using light pulses.

In 2005, Stanford scientist Karl Deisseroth discovered how to switch individual brain cells on and off by using light in a technique he dubbed 'optogenetics'.

Research teams around the world have since used this technique to study brain cells, heart cells, stem cells and others regulated by electrical signals.

However, light-sensitive proteins were efficient at switching cells on but proved less effective at turning them off.

Now, after almost a decade of research, scientists have been able to shut down the neurons as well as activate them.

Deisseroth's team has now re-engineered its light-sensitive proteins to switch cells much more adequately than before. His findings are presented in the journal Science.

Thomas Insel, director of the National Institute of Mental Health, which funded the study, said this improved "off" switch will help researchers to better understand the brain circuits involved in behavior, thinking and emotion.

In the upper left opsin, the red colour shows negative charges spanning the opsin that facilitated the flow of positive (stimulatory) ions through the channel into neurons. In the newly engineered channels (lower right), those negative charges have been changed to positive (blue), allowing the negatively charged inhibitory chloride ions to flow through. "This is something we and others in the field have sought for a very long time," Deisseroth, a senior author of the paper and professor of bioengineering and of psychiatry and behavioural sciences said.

"We're excited about this increased light sensitivity of inhibition in part because we think it will greatly enhance work in large-brained organisms like rats and primates."

The new techniques rely on changing 10 of the amino acids in the optogenetic protein.

"It creates a powerful tool that allows neuroscientists to apply a brake in any specific circuit with millisecond precision, beyond the power of any existing technology," Insel explained.

This technique could help scientists develop treatments for patients with some brain diseases as it could allow problematic parts of the brain to be switched off with light and tackled with minimal intrusion.

Merab Kokaia, PhD, a professor at Lund University Hospital in Sweden who has used optogenetics to study epilepsy and other conditions praised the research.

"These features could be much more useful for behavioural studies in animals but could also become an effective treatment alternative for neurological conditions where drugs do not work, such as some cases of severe epilepsy and other hyper-excitability disorders," he said.
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