MessageToEagle.com

Cool Layer Found Around The Sun's Twin - Alpha Centauri A

21 February, 2013


Share this story:
Follow us:

MessageToEagle.com - A few months ago, astronomers discovered a planet orbiting Alpha Centauri B, one of the closest stars to our own.

The Alpha Centauri triple star system consists of three stars - the Sun's nearest neighbors. The faint red dwarf, Proxima Centauri, is nearest at just 4.24 light-years, with the tight double star, Alpha Centauri AB, slightly further away at 4.37 light-years. is 4.37 light years away from Earth.

Alpha Centauri A is also very interesting celestial object of study as it's almost a twin to the Sun in mass, temperature, chemical composition and age, it provides an ideal natural laboratory to compare other characteristics of the two stars.



Click on image to enlarge

One of the great curiosities in solar science is that our Sun’s outer atmosphere – the corona – is heated to millions of degrees when its visible surface is ‘only’ about 6000 degrees. Even stranger is a curious temperature minimum of 4000 degrees lying between the two layers, in the chromosphere. Now, using ESA’s Herschel space observatory, scientists have made the first discovery of an equivalent cool layer in the atmosphere of the Sun-like star, Alpha Centauri A. Credits: ESA


Recently, ESA’s Herschel space observatory has detected a cool layer in the atmosphere of Alpha Centauri A, the first time this has been seen in a star beyond our own Sun. The finding is not only important for understanding the Sun’s activity, but could also help in the quest to discover proto-planetary systems around other stars.

The Sun’s wispy outer atmosphere – the corona – is heated to millions of degrees while the visible surface of the Sun is ‘only’ about 6000ºC.

Even stranger, there is a temperature minimum of about 4000ºC between the two layers, just a few hundred kilometres above the visible surface in the part of Sun’s atmosphere called the chromosphere.

Both layers can be seen during a total solar eclipse, when the Moon briefly blocks the bright face of the Sun: the chromosphere is a pink-red ring around the Sun, while the ghostly white plasma streamers of the corona extend out millions of kilometres.

The heating of the Sun’s atmosphere has been a conundrum for many years, but is likely to be related to the twisting and snapping of magnetic field lines sending energy rippling through the atmosphere and out into space – possibly in the direction of Earth – as solar storms. Why there is a temperature minimum has also long been of interest to solar scientists.


This artist’s impression shows the planet orbiting the star Alpha Centauri B, a member of the triple star system that is the closest to Earth. Alpha Centauri B is the most brilliant object in the sky and the other dazzling object is Alpha Centauri A. Our own Sun is visible to the upper right. The tiny signal of the planet was found with the HARPS spectrograph on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. Credit: ESO/L. Calçada/N. Risinger (skysurvey.org)


Now, by observing Alpha Centauri A in far-infrared light with Herschel and comparing the results with computer models of stellar atmospheres, scientists have made the first discovery of an equivalent cool layer in the atmosphere of another star.


Loading player...


“The study of these structures has been limited to the Sun until now, but we clearly see the signature of a similar temperature inversion layer at Alpha Centauri A,” says René Liseau of the Onsala Space Observatory, Sweden, and lead author of the paper presenting the results.

“Detailed observations of this kind for a variety of stars might help us decipher the origin of such layers and the overall atmospheric heating puzzle.”

MessageToEagle.com

See also:
Hunt For Distant Planets Continues

Follow MessageToEagle.com for the latest news on Facebook and Twitter !

Don't Miss Our Stories! Get Our Daily Email Newsletter

Enter your email address:


Once you have confirmed your email address, you will be subscribed to the newsletter.

Recommend this article:


The Wandering Stars

In ancient civilizations, people pondered the meanings of the stars, watching for clues to their survival: the beginning of planting and harvesting times, the seasons, and even portents of danger. They soon noticed that certain stars didn't stay in place, but wandered amongst the fixed star field.

Does Elusive Higgs Boson "God Particle" Really Exist?

Mysterious Dark Matter

Mysterious Flares Emitting From Sagittarius A

Subscribe To Our Space, Astronomy, Astrophysics, Earth and Xenology News!

Grab the latest RSS feeds right to your reader, desktop or mobile phone.

Subscribe to RSS headline updates from:
Powered by FeedBurner

Go to - MAIN PAGE

Copyright @ MessageToEagle.com All rights reserved.
Go to - MAIN PAGE

 Subscribe in a reader

Other Popular Articles

"The Most Profound Mystery In All Of Science" - Dark Energy
Little is known about this force and its its repulsive gravity, which is causing the expansion of the universe to accelerate. The riddles of dark matter and cosmic inflation, along with dark energy, these are the three pillars of modern cosmological theory," and none of them can be explained with physics that we know," Michael Turner, director of the Kavli Institute for Cosmological Physics says.

Doesn't Secret Dark Matter Exist?
The more scientists study dark matter they know lesser and are not particularly optimistic about their results. After completing this study, we know less about dark matter than we did before," said Matt Walker, of the Harvard-Smithsonian Center for Astrophysics. A mysterious and still unknown substance is totally invisible in the Universe and reveals its presence only through its gravitational pull.

Mysteries Of A Dark Universe
Cosmology, the study of the universe as a whole, has been turned on its head by a stunning discovery that the universe is flying apart in all directions at an ever-increasing rate. Is the universe really as we think it should be? Or is nature somehow fooling us? The astronomers whose data revealed this accelerating universe have been awarded the Nobel Prize for Physics.

Black Holes With No 'Table Manners' Eat Two Courses At Once!
It is still unknown how the supermassive black holes (SMBH) in galaxy centres accrete gas and grow. Researchers from the University of Leicester (UK) and Monash University in Australia have investigated how some black holes got so big so fast that they are billions of times heavier than the sun.

Mercury Surprises Scientists
On March 17, MESSENGER (MErcury Surface, Space Environment, GEochemistry, and Ranging) completed its one-year primary mission, orbiting Mercury, capturing nearly 100,000 images, and recording data that reveals new information about the planet's core, topography, and the mysterious radar bright material in the permanently shadowed areas near the poles.

Living Earth Simulator - Supercomputer Predicting The Future
In Douglas Adams book the Hitchhikers Guide to the Galaxy we encounter a machine called Deep Thought. It is the most powerful computer ever built. Deep Thought is capable of answering questions concerning life, the Universe, and simply everything. Now scientists are planning to create a similar machine. It is called the Living Earth Simulator (LES).

Warp-Speed Planets Are Some Of The Fastest Objects In The Milky Way
Warped planets are some of the fastest objects in the Milky Way and they zoom through space near the speed of light. Some years ago astronomers were astonished when they they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour. The discovery intrigued theorists, who wondered: If a star can get tossed outward at such an extreme velocity, could the same thing happen to planets?

Proof Of How The Universe Is Changing

Though the universe is filled with billions upon billions of stars, the discovery of a single variable star in 1923 altered the course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.

Bright Star In The Constellation Lyra Is Cooler Than The Human Body
The coldest class of stars have temperatures as cool as the human body. Astronomers hunted these dark orbs, termed Y dwarfs, for more than a decade without success. When viewed with a visible-light telescope, they are nearly impossible to see.

Thermonuclear Burning In A Neutron Star Detected For The First Time!
It's a very important discovery! For the first time, an international team of scientists have detected all phases of thermonuclear burning in a neutron star, located close to the center of the galaxy in the globular cluster Terzan 5.

Kepler Will Find Goldilocks Planet Within The Next Two Years
NASA's Kepler spacecraft is discovering a veritable avalanche of alien worlds. Recent finds include planets with double suns, massive "super-Earths" and "hot Jupiters," and a miniature solar system. The variety of planets circling distant suns is as wonderful as it is surprising.

Giant Jupiter - Our "Would-Be" Friend With Secrets From The Past

Mysterious Flares Emitting From Sagittarius A

Stars In The Milky Way Move In Mysterious Ways

W3Counter