APOD: Magellanic Clouds over Chile (2023 Feb 11)

[APOD Robot]

Magellanic Clouds over Chile

Explanation: The two prominent clouds in this Chilean Atacama Desert skyscape captured on January 21 actually lie beyond our Milky Way galaxy. Known as the Large and the Small Magellanic Clouds they are so named for the 16th century Portuguese explorer Ferdinand Magellan, leader of the first circumnavigation of planet Earth. Famous jewels of southern hemisphere skies, they are the brightest satellite galaxies of the Milky Way. The larger cloud is some 160,000 light-years, and the smaller 210,000 light-years distant. While both are irregular dwarf galaxies in their own right, they exhibit central barred structures in the deep wide-angle view. Wide and deep exposures also reveal faint dusty galactic cirrus nebulae and the imprints of gravitational tidal interactions between the Large and Small Magellanic Clouds.

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[Ann]

Magellanic Clouds over Chile
Image Credit & Copyright: Felipe Mac Auliffe López

Beautiful image! Unfortunately, it is so big that I had to post it as an attachment, and now I have used up one of my three attachments. Oh well...

Anyway, all the galactic cirrus seen in the image in the vicinity of the Large and Small Magellanic Clouds reminded me of the real action going on between these two galaxies, and between the Magellanic Clouds and the Milky Way. Because there is a lot going on!

Let's start with the action between the two Clouds of Magellan! There is a bridge of stars stretching between the LMC and the SMC:

The Magellanic Bridge stretches between the Large and the Small Magellanic Clouds. Credit: V. Belokurov / D. Erkal / A. Mellinger.

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There is a short Wikipedia stub on the Magellanic Bridge, and I'm going to quote all of it:

Wikipedia wrote:

The Magellanic Bridge (MBR) is a stream of neutral hydrogen that links the two Magellanic Clouds, with a few known stars inside it. It should not be confused with the Magellanic Stream, which links the Magellanic Clouds to the Milky Way. It was discovered in 1963 by J. V. Hindman et al.

There is a continuous stream of stars throughout the Bridge linking the Large Magellanic Cloud (LMC) with the Small Magellanic Cloud (SMC). This stellar bridge is of greater concentration in the western part. There are two major density clumps, one near the SMC, the other midway between the galaxies, referred to as the OGLE Island.

And hey! You've got to look at the gif on the Wikipedia page which is actually showing stars being pulled from the Small Magellanic Cloud to the Large Magellanic Cloud, using data from Gaia! Clicking on this link will take you directly to a 3.3 MB version of the gif.

There is more to see when it comes to bridges of gas and stars between the Magellanic Clouds, because some of this gas is being captured by the Milky Way and turned into the Magellanic Stream:

The Magellanic Stream, stretching from the Magellanic Bridge toward the Milky Way. Image Credit: NASA.

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NASA wrote:

Astronomers using NASA's Hubble Space Telescope have solved a 40-year mystery on the origin of the Magellanic Stream, a long ribbon of gas stretching nearly halfway around our Milky Way galaxy.

The Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way, are at the head of the gaseous stream. Since the stream's discovery by radio telescopes in the early 1970s, astronomers have wondered whether the gas comes from one or both of the satellite galaxies. New Hubble observations reveal most of the gas was stripped from the Small Magellanic Cloud about 2 billion years ago, and a second region of the stream originated more recently from the Large Magellanic Cloud...

You've all heard that Andromeda will collide with the Milky Way not in 3.9 billion years time, but only after 4.5 billion years, haven't you?

Future paths of the Milky Way, Andromeda and M33. Credit: ESA/Gaia.

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Well, don't heave a sigh of relief just yet. Because another set of fireworks awaits us much sooner, in just 2.4 billion years!

Sci News wrote:

Large Magellanic Cloud on Collision Course with Milky Way Galaxy

The Large Magellanic Cloud, a dwarf galaxy located approximately 163,000 light-years away, is on a collision course with the Milky Way with which it will merge in about 2.4 billion years, according to new research. This catastrophic event could wake up our Galaxy’s dormant supermassive black hole, which would begin devouring surrounding gas and increase in size by up to 8 times; the Milky Way’s stellar halo will undergo an equally impressive transformation, becoming 5 times more massive; the merger will also gravitationally eject central disk stars into the halo.

Us and the Magellanic Clouds: They are coming for us.

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So in order to find protection from the LMC bullet crashing into the Milky Way in 2.4 billion year's time, I guess we'll have to escape to, I suppose Mars, sooner than expected, shouldn't we?

Mars. Credit: NASA/Pathfinder

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Let's finish on a sweeter note. I found an absolutely gorgeous image of the Small Magellanic Cloud, and I have to show it to you. It is too large for me to just copy, so I'll have to show it to you as an attachment:

Small Magellanic Cloud. Credit: Cosmic Kiwi.

You have to go to this page to read about Cosmic Kiwi's project, and then click on the image to see the full size of it.

Anyway. You can see all the nebulas that form on one side of the Small Magellanic Cloud, to the upper right in the image I posted.

That is the beginning of the Magellanic Bridge. And from there, you can start picturing all the Magellanic fireworks that our galaxy is going to see.

Ann

[Holger Nielsen]

Ann, thank you for another well illustrated lecture! I found the image showing the future parts of the Local Group galaxies particularly interesting.

[Fred the Cat]

Dust, the final frontier. Following its trek throughout time, and the episodes of the universe, give enterprising astronomers a lot more than a five year mission.

Seeking out new careers, they boldly explore the cosmic origins of dust bunnies.

[alter-ego]

Funny, I was surprised by seeing a globular cluster (47 Tuc) so close to the SMC. I've never appreciated that fact; I guess that detail has never sunk in
I really like that image.

[orin stepanek]

Nice rendition Ann; I liked your explanation of
todays APOD! You can tell you're a teacher!
I knew there were attachments to The Milky
Way! but ddidn't pay any attention to attach
ments to each other!

[johnnydeep]

Funny, I was surprised by seeing a globular cluster (47 Tuc) so close to the SMC. I've never appreciated that fact; I guess that detail has never sunk in
I really like that image.

And don't overlook the smaller NGC 362 globular cluster (aka Caldwell 104) even closer to the SMC! It's clearly seen at the bottom in the remarkable image from the "Kiwi" site that Ann posted. For more, see https://www.nasa.gov/feature/goddard/caldwell-104:

Astronomers have discovered that Caldwell 104 boasts a surprisingly high metal content, which means that it formed more recently than expected. Most globular clusters are much older than the majority of stars in their host galaxy, but the stars in Caldwell 104 appear to be 2 billion to 3 billion years younger than stars in other Milky Way globulars. Astronomers have used Hubble multiple times to investigate the young cluster’s stellar population. This image was taken in visible light using Hubble’s Advanced Camera for Surveys. Discovered from Australia by Scottish astronomer James Dunlop in 1826, Caldwell 104 cannot be viewed from the Northern Hemisphere except near the equator, but it can be seen year-round from mid-Southern latitudes in the constellation Tucana, near the Small Magellanic Cloud. Binoculars or a modest telescope will provide a somewhat hazy view of the magnitude-6.4 cluster, but a large telescope will reveal individual stars.

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https://www.nasa.gov/sites/default/file ... c104-1.jpg

And it's even better seen here: http://sguisard.astrosurf.com/Pagim/SMC ... mm-V1.html