APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

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APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby APOD Robot » Sun Dec 14, 2014 5:05 am

Image Molecular Cloud Barnard 68

Explanation: Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchus known as Barnard 68, pictured above. That no stars are visible in the center indicates that Barnard 68 is relatively nearby, with measurements placing it about 500 light-years away and half a light-year across. It is not known exactly how molecular clouds like Barnard 68 form, but it is known that these clouds are themselves likely places for new stars to form. In fact, Barnard 68 itself has been found likely to collapse and form a new star system. It is possible to look right through the cloud in infrared light.

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BDanielMayfield » Sun Dec 14, 2014 6:15 am

Reminds me of a few episodes in the Star Trek franchise that had the various ships having to cross "null space" or other perilous regions of total darkness. This one seems quite small and tame by comparison. Steady as she goes Mr. Sulu. Let's see what's in there ...
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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby Boomer12k » Sun Dec 14, 2014 8:46 am

Doctor: "I am sorry Milky Way....you have a Brain Cloud...."

With apologies to "Joe Vs The Volcano".... :ssmile:

One cannot see the Molecular Cloud for all that dust....

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby hoohaw » Sun Dec 14, 2014 11:58 am

Looking in the infrared reveals the secret of Barnard 68 !
http://stardate.org/astro-guide/gallery ... g-darkness

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BDanielMayfield » Sun Dec 14, 2014 2:02 pm

Barnyard, err Barnard 68 is so little, and it wiggles and it jiggles "like a soap bubble or a water filled balloon" according to that link.

What a fascinating object! Only 0.5 ly wide and amassing only about 2 Sun's worth of material, it's just tiny as nebulas go. And at only 500 lys away, it will be easy to study over the next (geologically) short 100,000 years as it condenses into a protostar. That is just too cool! I'm stoked y'all. :ssmile:

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby aljo » Sun Dec 14, 2014 2:09 pm

It is surprising that the object is 500 LY away and yet there is not a single star in front of it. There are so many stars in that area that one would expect a few of them to be closer than the cloud.

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BDanielMayfield » Sun Dec 14, 2014 3:08 pm

aljo wrote:It is surprising that the object is 500 LY away and yet there is not a single star in front of it. There are so many stars in that area that one would expect a few of them to be closer than the cloud.


Welcome aljo. It's not that surprising if you do the math. The volume of a cone with a 0.5 ly base and a 500 ly height is V=pi*0.252*500/3, which comes out to about 33 cubic lys. But in our area of the Milky Way the stellar density is only about 0.004 stars per ly3. 0.004 x 33 = 0.13, which means for an object of this size at this distance the odds would only be 13% for a star to be between us and it.

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby Ron-Astro Pharmacist » Sun Dec 14, 2014 5:27 pm

I was curious about how many of these objects dwell in our vicinity. A quick search found relatively few articles. Being so small it might be that they are difficult to discover. Recent APOD's have featured T Tauri stars but they were found using long wavelength devices.

http://apod.nasa.gov/apod/ap141110.html

The attached article seems to indicate association with X-ray emission. What other resources can be used to located such small objects in our large galaxy; let alone universe? It may show how small our toolbox really is. :?: :idea: :!:
http://iopscience.iop.org/1538-4357/507/1/L83/pdf/1538-4357_507_1_L83.pdf

http://en.wikipedia.org/wiki/T_Tauri_star
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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby Ron-Astro Pharmacist » Sun Dec 14, 2014 5:31 pm

At least - my toolbox :D
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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby ta152h0 » Sun Dec 14, 2014 6:19 pm

it has to be very cold in there
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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby rstevenson » Sun Dec 14, 2014 8:17 pm

ta152h0 wrote:it has to be very cold in there

A wee bit chilly -- about 10 to 20 Kelvin (-263 to -253 °C). :brr: If a molecular cloud gets as balmy as 100 K, it will not be able to condense into stellar systems.

Rob

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BennyH » Sun Dec 14, 2014 10:11 pm

BDanielMayfield wrote:Reminds me of a few episodes in the Star Trek franchise that had the various ships having to cross "null space" or other perilous regions of total darkness. This one seems quite small and tame by comparison. Steady as she goes Mr. Sulu. Let's see what's in there ...


Did you ever read "The Black Cloud" by Fred Hoyle :-)

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BDanielMayfield » Mon Dec 15, 2014 12:46 am

BennyH wrote:
BDanielMayfield wrote:Reminds me of a few episodes in the Star Trek franchise that had the various ships having to cross "null space" or other perilous regions of total darkness. This one seems quite small and tame by comparison. Steady as she goes Mr. Sulu. Let's see what's in there ...


Did you ever read "The Black Cloud" by Fred Hoyle :-)


No, I haven't BennyH. Hadn't even heard of The Black Cloud in fact. I have heard of Fred Hoyle of course though, famous for his work on the now disproven Steady State Theory of cosmology, his very important work on how stars produce energy and the elements, and as one of the originators of the panspermia notion; the idea that life can be spread naturally across the vast distances of interstellar space.

As nuclear astrophysics is one of my favorite branches of astronomy I'm very fond of Hoyle's insights into nucleosynthesis. The other two of his ideas he's remembered for, na. From what I've just read his novel The Black Cloud was an attempt to get his panspermia notions out to a wider audience after it had received much scorn in the astronomical community.

Was it a good read Benny? Sounds like it may have inspired some si-fi scripts. They kept finding dangerous alien creatures lurking in the voids. :shock:

Bruce
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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BennyH » Mon Dec 15, 2014 11:49 pm

I liked it.
Considered it was written before computers and "Gene Roddenberry", I think it was great reading.
Maybe in same league as "2001".
It also give some thoughts about how science and politics suddenly stands opposed to each other, when an entity visits our little sun to collect energy, without even knowing there is life on one of the planets.

Aliens might not be as bad as we like to think... maybe they are even smarter than so, just leaving us alone :-)

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby BMAONE23 » Tue Dec 16, 2014 6:02 pm

A 1959 classic 'hard' science-fiction novel by renowned Cambridge astronomer and cosmologist Fred Hoyle. Tracks the progress of a giant black cloud that comes towards Earth and sits in front of the sun, causing widespread panic and death. A select group of scientists and astronomers - including the dignified Astronomer Royal, the pipe smoking Dr Marlowe and the maverick, eccentric Professor Kingsly - engage in a mad race to understand and communicate with the cloud, battling against trigger happy politicians.


In the pacy, engaging style of John Wyndham and John Christopher, with plenty of hard science thrown in to add to the chillingly credible premise (he manages to foretell Artificial Intelligence, Optical Character Recognition and Text-to-Speech converters), Hoyle carries you breathlessly through to its thrilling end.

Image

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Re: APOD: Molecular Cloud Barnard 68 (2014 Dec 14)

Postby felopaul » Mon Dec 22, 2014 12:09 am

fascinating object


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