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Saturday, October 17, 2009

Kewl photo of Barnard's Galaxy




Source of Image:ESO: European Organisation for Astronomical Research in the Southern Hemisphere

A kewl photo of Barnard's Galaxy has been released to the public. The image,  which was taken using the Wide Field Imager attached to the 2.2-meter telescope at the European Southern Observatory's facility in northern Chile,shows the  rich star formation and curious nebulae, like the bubble clearly visible in the upper left of this photo. Astronomers classify NGC 6822 as an irregular dwarf galaxy because of its odd shape and relatively small size by galactic standards. The strange shapes of these cosmic misfits help researchers understand how galaxies interact, evolve and occasionally "cannibalize" each other, leaving behind radiant, star-filled scraps.

Here are some facts concerning Barnard's Galaxy:

(1) At a distance of 1.7 million light years away, NGC 6822 is literally right around the corner. This galaxy is a dwarf with a mere 10 million stellar members (stars)  in its ranks. Note the "bubble" of gas in the top right corner. This bubble was probably caused by stars that formed from their natal gas cloud. Upon their birth, the extra gas in the cloud was expelled into space- pushed out by the energetic stellar winds of the baby stars. Since this galaxy (especially on the outskirts) does not have much in the way of internal motions, the bubble of gas continues to expand without anything disrupting it. (source:http://www.noao.edu/outreach/aop/observers/n6822.html)

(2).Barnard's Galaxy or NGC 6822 is a small irregular galaxy only 14 degrees east of the galactic plane in the constellation of Sagittarius.The low surface brightness of the galaxy itself combined with the relatively bright H II regions has lead to a great deal of confusion over its identity during the late 19th to early 20th centuries. E.E Barnard first observed the galaxy on August 17, 1884 with a 5-inch refractor. He described the object as.. "an excessively faint nebula" and "it is some 2' in diameter, and is very diffuse and even in its light" (Barnard, 1884). He later determined its position with a 6-inch equatorial and noted it was "seen with difficulty", while in the 5-inch at 30x it was "quite distinct". In 1885, he examined it again with a 6-inch refractor and a "comet" eyepiece. The wide field boosted the visibility of the galaxy, and Barnard made a most unusual observation (Hubble, 1925):
It certainly seems much larger and much denser than last year and I certainly think it has increased in density and size since that time...If it had always been as large and bright as now, I cannot conceive how it could have been missed by observers when examining G.C. 4510 (the bright planetary nebula NGC 6818, which is about 40' north preceding). Probably this is a variable nebula.Barnard's Galaxy consists of a "bright" central bar embedded in a broad oval halo of lower surface brightness.
(Source:http://astronomy-mall.com/Adventures.In.Deep.Space/barnard.htm)


(3)At only about a tenth of the Milky Way's size, Barnard’s Galaxy fits its dwarfish classification. All told, it contains about 10 million stars — a far cry from the Milky Way’s estimated 400 billion. In the Local Group, as elsewhere in the Universe, however, dwarf galaxies outnumber their larger, shapelier cousins. (source:http://www.eso.org/public/outreach/press-rel/pr-2009/pr-38-09.html)


(4) Irregular dwarf galaxies like Barnard's get their bloblike forms from close encounters with other galaxies. Gravity's attraction can dramatically scramble the shapes of the passing or colliding galaxies, pulling and flinging stars and forming irregularly shaped dwarf galaxies like NGC 6822. (Source:http://www.scientificamerican.com/gallery_directory.cfm?photo_id=5A39A461-B457-F898-FBA5164576038E23)


(5)In the new photograph, which was snapped using the Wide Field Imager (WFI) instrument, reddish nebula regions are clearly visible within Barnard's Galaxy, hinting at areas of intense stellar formation. In these regions, young, blue stars heat up the gas around them, generating the hellish, red glow. The image also reveals, in its upper-left part, a peculiar, bubble-shaped nebula, a very rare class of cosmic structures. A clutch of massive, scorching stars adorns the galactic core, and the energy waves it generates slam at great speeds into the interstellar matter around it. (source:http://news.softpedia.com/news/Astronomers-Image-Barnard-039-s-Galaxy-124264.shtml)




(6) The red bubbles are regions where stars are being born in large numbers; the UV and fierce winds of subatomic particles from the massive stars being formed carve out cavities in the gas, creating what look like smoke rings. The red glow is characteristic of hot hydrogen, and is a sure-fire way to know that gas is being excited by the stars nearby. The sharp edges to the bubbles are real, due to the gas piling up as it rams gas in interstellar space in a cosmic snowplow effect.There is another feature here that’s not obvious. On the left and right of the galaxy are faint, thick, blue arcs. This is actually gas that’s being blown out by the stars in the center of the galaxy, forming a weak ring surrounding the entire structure. I expect that gas will blow right out of the galaxy entirely; the gravity from the meager number of stars making up Barnard’s Galaxy can’t possibly be enough to restrain it.(source:http://blogs.discovermagazine.com/badastronomy/2009/10/14/barnards-beauty/)


You can see a very kewl zoom in video of Barnard's Galaxy posted at Youtube by clicking on this link:
http://www.youtube.com/watch?v=EmnuszxNnNU


I hope you have enjoyed learning about Barnard's Galaxy, I sure have!

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Thoughts worth thinking about

"Our subconscious minds have no sense of humor, play no jokes and cannot tell the difference between reality and an imagined thought or image. What we continually think about eventually will manifest in our lives."-Sidney Madwed



Laws alone can not secure freedom of expression; in order that every woman and man present their views without penalty, there must be spirit of tolerance in the entire population.- Albert Einstein Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn a life around. - Leo Buscaglia



A person's true wealth is the good he or she does in the world. - Mohammed



Our task must be to free ourselves... by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty. -Albert Einstein



The best way to find yourself, is to lose yourself in the service of others. - Ghandi



The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves. - Helen Keller



Aim for success, not perfection. Never give up your right to be wrong, because then you will lose the ability to learn new things and move forward with your life. Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make yourself a happier and more productive person. - Dr. David M. Burns



Life is as dear to a mute creature as it is to man. Just as one wants happiness and fears pain, just as one wants to live and not die, so do other creatures. -His Holiness The Dalai Lama



Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude towards those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it. -



Milan Kundera, The Unbearable Lightness of Being



The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity. -George Bernard Shaw

Ego's trick is to make us lose sight of our interdependence. That kind of ego-thought gives us a perfect justification to look out only for ourselves. But that is far from the truth. In reality we all depend on each other and we have to help each other. The husband has to help his wife, the wife has to help the husband, the mother has to help her children, and the children are supposed to help the parents too, whether they want to or not.-Gehlek Rinpoche Source: "The Best Buddhist Writing 2005 pg. 165

The hostile attitude of conquering nature ignores the basic interdependence of all things and events---that the world beyond the skin is actually an extension of our own bodies---and will end in destroying the very environment from which we emerge and upon which our whole life depends.