The Milky Way just got Larger

nivek

As Above So Below
The Milky Way just got larger


The Milky Way's near neighbor, the Andromeda Galaxy.

Despite residing in it, it’s hard for us to know exactly how big the Milky Way is. But new research has found that our galaxy is bigger than previously thought. Using a large survey of stars instead of just models (as previous researchers did), astronomers have now determined the disk of our galaxy to be 200,000 light-years across — twice as large as was believed a decade ago.

Astronomers know the Milky Way to be a spiral galaxy with a flat central disk composed of spiraling arms and a sparse outer cloud of stars called the halo. Most of the stars are found in the disk, which rapidly thins out at the edges. The size of the galaxy is measured from the point at which the number of stars in the disk significantly drops, so finding disk stars is key to determining the Milky Way’s size.

Fortuitously, disk stars tend to be much younger than the halo stars. Since stars gradually build up elements over generations, the disk stars’ composition can be differentiated from the halo stars, allowing astronomers to figure out which stars belong to which population.


An annotated map showing the Milky Way's structure, based on measurements to distant stars and other objects.

Finding the outer reaches
With a process known as spectroscopy, researchers from the Instituto de Astrofísica de Canarias and at the National Astronomical Observatories of Beijing studied the chemical composition of over 4,600 stars from two surveys, APOGEE and LAMOST, and mapped out which stars are part of the disk and which belong to the halo. The results, published May 7 in the journal Astronomy and Astrophysics, clearly show disk stars much farther from center of the galaxy than before.

“Certainly, one would expect the existence of stars at very far distances from the galactic center, as part of the halo,” says Martín López Corredoira, lead author on the paper and researcher at Instituto de Astrofísica de Canaria. “But, as far as we know, nobody could previously say that stars [farther than 81,000 light-years] are confirmed spectroscopically to belong to the disk.”

Bigger, not heavier
The researchers still believe the density of stars at the edge tapers off in an exponential manner — just farther away than previously thought. Although its diameter has been supersized, the Milky Way is still smaller than its neighbor Andromeda, which measures over 220,000 light-years across.

While our galaxy is looking larger, it’s not putting on much weight. Because the outer reaches are much less dense than the center of the galaxy, the additional area is only sparsely populated with stars. These few extra stars are only a drop in the bucket compared to the rest of the galaxy, so overall the mass of the Milky Way remains largely unchanged.

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Standingstones

Celestial
The Milky Way just got larger


The Milky Way's near neighbor, the Andromeda Galaxy.

Despite residing in it, it’s hard for us to know exactly how big the Milky Way is. But new research has found that our galaxy is bigger than previously thought. Using a large survey of stars instead of just models (as previous researchers did), astronomers have now determined the disk of our galaxy to be 200,000 light-years across — twice as large as was believed a decade ago.

Astronomers know the Milky Way to be a spiral galaxy with a flat central disk composed of spiraling arms and a sparse outer cloud of stars called the halo. Most of the stars are found in the disk, which rapidly thins out at the edges. The size of the galaxy is measured from the point at which the number of stars in the disk significantly drops, so finding disk stars is key to determining the Milky Way’s size.

Fortuitously, disk stars tend to be much younger than the halo stars. Since stars gradually build up elements over generations, the disk stars’ composition can be differentiated from the halo stars, allowing astronomers to figure out which stars belong to which population.


An annotated map showing the Milky Way's structure, based on measurements to distant stars and other objects.

Finding the outer reaches
With a process known as spectroscopy, researchers from the Instituto de Astrofísica de Canarias and at the National Astronomical Observatories of Beijing studied the chemical composition of over 4,600 stars from two surveys, APOGEE and LAMOST, and mapped out which stars are part of the disk and which belong to the halo. The results, published May 7 in the journal Astronomy and Astrophysics, clearly show disk stars much farther from center of the galaxy than before.

“Certainly, one would expect the existence of stars at very far distances from the galactic center, as part of the halo,” says Martín López Corredoira, lead author on the paper and researcher at Instituto de Astrofísica de Canaria. “But, as far as we know, nobody could previously say that stars [farther than 81,000 light-years] are confirmed spectroscopically to belong to the disk.”

Bigger, not heavier
The researchers still believe the density of stars at the edge tapers off in an exponential manner — just farther away than previously thought. Although its diameter has been supersized, the Milky Way is still smaller than its neighbor Andromeda, which measures over 220,000 light-years across.

While our galaxy is looking larger, it’s not putting on much weight. Because the outer reaches are much less dense than the center of the galaxy, the additional area is only sparsely populated with stars. These few extra stars are only a drop in the bucket compared to the rest of the galaxy, so overall the mass of the Milky Way remains largely unchanged.

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I recall reading an article stating that some billions of years in the future the Milky Way and Andromeda galaxies will collide and become a super galaxy of sorts. We just won’t be around to experience it.
 

nivek

As Above So Below

CasualBystander

Celestial
The Milky Way just got larger


The Milky Way's near neighbor, the Andromeda Galaxy.

Despite residing in it, it’s hard for us to know exactly how big the Milky Way is. But new research has found that our galaxy is bigger than previously thought. Using a large survey of stars instead of just models (as previous researchers did), astronomers have now determined the disk of our galaxy to be 200,000 light-years across — twice as large as was believed a decade ago.

Astronomers know the Milky Way to be a spiral galaxy with a flat central disk composed of spiraling arms and a sparse outer cloud of stars called the halo. Most of the stars are found in the disk, which rapidly thins out at the edges. The size of the galaxy is measured from the point at which the number of stars in the disk significantly drops, so finding disk stars is key to determining the Milky Way’s size.

Fortuitously, disk stars tend to be much younger than the halo stars. Since stars gradually build up elements over generations, the disk stars’ composition can be differentiated from the halo stars, allowing astronomers to figure out which stars belong to which population.


An annotated map showing the Milky Way's structure, based on measurements to distant stars and other objects.

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Why does our galaxy have 5 arms and no legs???
 

Shadowprophet

Truthiness
I recall reading an article stating that some billions of years in the future the Milky Way and Andromeda galaxies will collide and become a super galaxy of sorts. We just won’t be around to experience it.
From 5:26 to 6:20 is a simulation of The milky way and Andromeda galaxy colliding,
 

nivek

As Above So Below
From 5:26 to 6:20 is a simulation of The milky way and Andromeda galaxy colliding,


Awesome, thanks, I meant to post on of those video simulations last night but was tired and forgot lol...

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Toroid

Founding Member
What else is wrong as far as size, distance and age of celestial bodies? Now we're about the same size as the Andromeda galaxy at 220,000 light years across. The Milky Way is estimated at 13.51 billion years old and the universe is 13.7 billion. The rotation rate of our galaxy is between 220 to 360 million years. I heard recently that all galaxies have the same rotation rate at about once per one billion years. At that rate our galaxy has only made 13 revolutions and at 220 million years it's 61 rotations. Something is very wrong because galaxies are too well formed for so few rotations.
Milky Way - Wikipedia
Andromeda Galaxy - Wikipedia
 

SOUL-DRIFTER

Life Long Researcher
What else is wrong as far as size, distance and age of celestial bodies? Now we're about the same size as the Andromeda galaxy at 220,000 light years across. The Milky Way is estimated at 13.51 billion years old and the universe is 13.7 billion. The rotation rate of our galaxy is between 220 to 360 million years. I heard recently that all galaxies have the same rotation rate at about once per one billion years. At that rate our galaxy has only made 13 revolutions and at 220 million years it's 61 rotations. Something is very wrong because galaxies are too well formed for so few rotations.
Milky Way - Wikipedia
Andromeda Galaxy - Wikipedia
I tend to agree.
Maybe dark matter or energy is to blame?
 

nivek

As Above So Below
Something is very wrong because galaxies are too well formed for so few rotations.

The universe is much older than is presently understood by scientists...They are wrong because of lack of data I think more so than out of ignorance...Sometimes scientific discovery is slow lol...

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