Questions tagged [spiral-arms]

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43
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2answers
4k views

Does the sun cross other spiral arms in its movement around the galaxy's center?

Today, Ansa.it released an article that states: [...]. In questo suo peregrinare galattico, il Sole ha attraversato anche i due bracci della Via Lattea Perseo e Centauro. "Sono zone di alta ...
3
votes
2answers
110 views

Are magnetic field lines Spiral for Spiral Galaxies? If no, then how it look like topologically?

I am an undergraduate doing summer project at USO. I am working on Sun's Magnetic field model. I got spiral graph for that, which looks like any spiral Galaxy. Do you think that there is some ...
2
votes
1answer
34 views

Relationship between galactic rotation and stellar lifetime

I have read that the lifetime of stars is much less than the period of rotation for a spiral galaxy. For example https://www.coursera.org/learn/evolvinguniverse/lecture/wlYhz/the-origin-of-spiral-arms ...
4
votes
1answer
526 views

How is the bar formed in a Barred-Spiral galaxy?

How does the bar in a barred spiral galaxy form? What prevents it from being spirals all the way down like water spiralling down a plughole?
0
votes
1answer
107 views

What are evidences of stationarity of rotation of galaxies

Recently I have found the article Does There Really Exist the Problem of the Dark Matter in Spiral Galaxies? which states that dark matter does not exist because astronomers are wrong assuming ...
0
votes
1answer
3k views

In which direction does the Milky Way rotate?

We don't have a photo of our Milky Way the whole, all the pictures are artists' interpretations showing a bulge, a central bar, and several spiral arms. The milky way is spinning. I would like to know:...
2
votes
1answer
100 views

Have parameters been determined for the Fourier components of a Milky Way spiral density-potential model?

Spiral arms in galaxies can be modeled by potentials of the form $$\Phi_{\text{spiral}}(R,\theta,z,t)=\sum_mA_m(R,z)\cos(m\theta-m\theta_0-\phi_m(R)-\Omega_pt)$$ where $A_m(R,z)$ is the $m$th-order ...
11
votes
1answer
902 views

Do we know if we are overtaking or falling behind our arm?

Here's our galaxy as best we know, courtesy of this Wikipedia article: It seems that as best we know, each arm is a compressed or brighter area (rather like a wave). Looking at that image, do we ...