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First Global Map Outside the Solar System

timothy posted 1 year,1 day | from the faked-just-like-the-moon-landings dept.

Space 19

First time accepted submitter Kreuzfeld writes "For many years, astronomers have suspected that brown dwarfs — 'failed stars' with masses between those of planets and stars — have cloudy atmospheres. Our recent paper in Nature presents the first global, 2D map of the patchy clouds in the atmosphere of a brown dwarf: our neighbor, the 6.5 light-years-distant Luhman 16B. Eventually, astronomers will use this technique to make weather movies of global cloud patterns on brown dwarfs and extrasolar planets."

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Insert (-1)

CheezburgerBrown . (3417019) | 1 year,1 day | (#46111959)

Brown Dwarf joke here

Re:Insert (1)

lennier1 (264730) | 1 year,1 day | (#46112225)

The red version is much better.

How is this a "global map" ? (1)

ReekRend (843787) | 1 year,1 day | (#46112049)

How is this a "global map" ? It seems at best to be an "atmospheric" map, which I'm sure is interesting although usually a bunch of clouds that never stop moving.

Re:How is this a "global map" ? (1)

geekoid (135745) | 1 year,1 day | (#46112067)

the stars are globe shaped.

Re:How is this a "global map" ? (0)

Anonymous Coward | 1 year,1 day | (#46112699)

Clouds: constantly moving aggregation of solids floating on a fluid
Continents: constantly moving aggregation of solids floating on a fluid

Not so different.

Not so different? (1)

Dr. Zim (21278) | 1 year,1 day | (#46112771)

Except for the vast orders of magnitude difference in which speed at which the two move, you're almost correct.

Fascinating! (-1, Troll)

grub (11606) | 1 year,1 day | (#46112077)

The picture looks like 3 giant testicles. Do other distant brown dwarfs have the same 3 testicle look to them? Do creatures on other planets have 3 testicles, if they do indeed have testicles?

If other planetary life forms were divided in to two sexes, would one have 3 ovaries to compliment the others 3 testicles?


Re:Fascinating! (0)

Anonymous Coward | 1 year,1 day | (#46112199)

+1 insightful

curious orientation (4, Interesting)

somepunk (720296) | 1 year,1 day | (#46112285)

The large scale structure seems to stretch between the poles, at fairly constant longitude, rather than around the axis at fairly constant latitude, like every other atmosphere we've encountered. Is there some reason they are really that way, or is it some artifact of the data gathering and rerduction?

Re:curious orientation (5, Informative)

Kreuzfeld (308371) | 1 year,1 day | (#46112517)

Good question! Atmospheric scientists aren't actually sure yet whether brown dwarfs should have "bands" like we see on Jupiter and other Solar system gas giants (this was discussed at a meeting in Washington, D.C. Jan 2014) -- and our mapping data wasn't quite sensitive enough to definitively answer that question. (We're less sensitive to axisymmetric features than we are to longitudinal variations). The vertical "stretching" of the map's features toward the poles is an unavoidable artifact of our analysis technique [wikipedia.org] . Cloud patterns may be less elongated than they appear!

Re:curious orientation (1)

hackertourist (2202674) | 1 year,1 day | (#46113047)

Still, congratulations. It's amazing that we've gone from stars visible only as a single pixel to being able to detect surface features.

This is why I love slashdot (1)

steamraven (2428480) | 1 year,1 day | (#46115627)

This is why I love Slashdot: Comments by the scientists involved! Thanks for your hard work guys!

Re:curious orientation (1)

fyngyrz (762201) | 1 year,1 day | (#46112633)

The large scale structure seems to stretch between the poles

That's pretty normal for two testicles as well, you know. Although I'm only familiar with monopole structure.

Re:curious orientation (1)

PPH (736903) | 1 year,1 day | (#46116671)

It sort of makes sense if you read the way that the atmosphere is being mapped. Using the Doppler shift to detect when a brighter spot is approaching or receding can give some data on the longitude of these spots. The latitude data may be more difficult (but not impossible) to deduce.

Old Map... (1)

Anonymous Coward | 1 year,1 day | (#46112849)

This map is 6.5 years old already.

How they did it (0)

Anonymous Coward | 1 year,1 day | (#46115673)

The brown dwarf they imaged was found only a few months ago, yet it is only 6.5 light years away, using data from WISE. This fact, along with the very productive results from the Kepler mission, make me hopeful that our knowledge of our neighbourhood in the Milky Way can greatly improve in the next few decades so long as we continue funding specialized space-based telescopes.

The actual mapping was done using ground-based telescopes. I found this description of how they accomplished the mapping quite interesting:


How did the researchers manage to reconstruct a surface map, and how did they uncover the layer structure?
With current technology, it is not possible to produce surface maps of this brown dwarf (or other distant stars and brown dwarfs) in the same way that we would, say, map the cloud bands of Jupiter, namely by directly taking images that show all the details.

The indirect technique used instead is called Doppler imaging. It makes use of the fact that light from a rotating star is slightly shifted in frequency as the star rotates. From the systematic shifts, an approximate map of the stellar surface can be reconstructed.

For a rough picture of how this happens, imagine that you are hovering high above the Earth's equator, watching the globe spin beneath you. As an object sitting on the equator comes into view, it will first move toward you while crossing the horizon and coming into sight; as it passes directly beneath you, its distance from you will change very slowly, and as it passes across your horizon out of sight, it will move away from you at speed. An object placed at higher latitudes (that is, shifted towards one of the poles) will follow a similar pattern, but at overall lower speeds. An object situated at one of the poles will not move towards you or away from you at all as the Earth rotates.

Now imagine the same situation for a brown dwarf. When a bright spot rotates into sight, the way it moves directly towards or away from you will depend on latitude, while the timing of when it rotates into and out of sight defines its longitude. And while astronomers cannot follow the spot's travels directly, there's the so-called Doppler shift: Light will change its wavelength very slightly depending on whether, and how fast, the emitting object is moving towards or away from the observer. Combining the Doppler shift patterns hinting at latitude with timing carrying information about longitude, the astronomers can attempt to reconstruct the brown dwarf's surface pattern. The reconstruction involves some ambiguity and uncertainty, but the result shown here is the most probably surface structure deduced from the many Doppler measurements made by Crossfield et al.

Starcraft (1)

romit_icarus (613431) | 1 year,1 day | (#46117391)

Will it be possible to import this map into Starcraft? A DLC, even?

Re:Starcraft (1)

Kreuzfeld (308371) | 1 year,23 hours | (#46118161)

The flat (Mercator-projected) map of Luhman 16B is available here for download [mpia-hd.mpg.de] . Feel free to import it into whatever program or game you prefer!

Other dwarfs (1)

pyrokey3 (2835821) | about a year ago | (#46193315)

As there are different types of dwarf planets (such as brown dwarf), what different types are there and how do we differentiate from them?
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