Questions regarding systems of large numbers of stars held together by gravity.

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4
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5answers
270 views

Can the Milky Way be seen with the naked eye? Does this apply to any galaxy? If yes, then how and when?

I have seen different pictures in a different community to showcasing the Milky Way. I can never tell whether it's edited or it's the real picture. Actually, I can never see any galaxy as such by with ...
0
votes
1answer
92 views

Evidence that galaxies are made of billions of stars?

What is the evidence that galaxies are made of billions of stars? Even faint galaxies? Can spectral analysis distinguish galaxies from individual stars?
1
vote
2answers
161 views

Is the North star going to stay in the North sky?

Considering how the our solar system, and how every other star in the galaxy is traveling through the cosmos, it seems like it's a miracle that the stars and constellations in the sky stay as constant ...
3
votes
2answers
108 views

How to tell a nebula from a galaxy?

Not all galaxies are spiral in shape[1][2], some nebulae are huge[3] and nebula are the nursery of stars[4]. How to tell them apart? Note I have already compare the contents for galaxy and a nebula, ...
3
votes
1answer
74 views

How to differentiate between images of a gravitationally lensed object

The light coming from a distant galaxy or star can be distorted en route to Earth; this distortion is caused by the curvature of space when a massive object is present. My question is, how can we tell ...
2
votes
0answers
47 views

Spectral analysis of AGN (velocity dispersion of galaxy absorption, doppler shifts)

I was wondering what parameters I need to know/measure to calculate the velocity dispersion of a galaxy, specifically an AGN. Also, I have spectra where there are blueshifted and redshifted ...
2
votes
2answers
117 views

Galactic extinction as a function of distance

I am looking at several galactic sources in the $I$, $R$ and $V$ bands and I want to calculate their absolute magnitudes. I can get the apparent magnitude and I know the distance so I just need to ...
3
votes
2answers
166 views

What is the direction of the movement of the solar system in relation to the galaxy's plane

I got from this answer that the axis of the solar system is tilted of about 63 degrees in relation to that of our galaxy, so I can assume that we move through space (at least locally) roughly in a ...
1
vote
2answers
1k views

How much of the Milky Way is visible to the naked eye from earth?

When we see the Milky Way on a dark night are we seeing the bulk of the galaxy, or just our local arm? How much of the milky way is visible to the naked eye on a dark night?
1
vote
1answer
799 views

Does our sun/solar system orbit around any other celestial objects? [duplicate]

Does our solar system orbit around another massive celestial object? Like a massive star or black hole for instance? From my understanding our sun rotates around the centre of our galaxy, thus our ...
0
votes
1answer
39 views

Mass resolution

Can someone define mass resolution in terms of cosmological simulations such as the millennium simulation? Is it just the smallest mass that a dark mater particle can have and still be detected by the ...
2
votes
1answer
73 views

What will the mass of the new galaxy be?

When the Milky Way galaxy collides with the Andromeda galaxy, what will the mass and volume of the new galaxy be?
2
votes
1answer
118 views

Are galaxies moving away from us faster than before?

Are all galaxies moving away from us at constant speed even those that may be moving in our direction as the space is being formed? How does nothingness appear to push matter? A black hole sucks as ...
2
votes
2answers
126 views

What's this red stuff in some astronomical photos, e.g. Centaurus A?

Sorry for the rookie question, but I've got no idea about that red "belt" crossing over center of the galaxy, in this photo. I've actually tried all sorts of google searches but I couldn't get ...
0
votes
1answer
63 views

Help w/ Hubble's Law + Doppler Effect.

I had a question about the following chart. What mathematical observation or equation could be made about the data given in respect to the doppler effect? I'm confused if this means that planets are ...
1
vote
2answers
227 views

How do astronomers estimate the total mass of dust in clouds and galaxies?

As I understand it astronomers estimate the mass of stars by studying the orbits of their companions (other stars or planets). This helps them to derive relationships between the luminosities and ...
3
votes
1answer
67 views

How can a galaxy in-between our view and the galaxy behind it have a 'lensing effect'?

In this article, the author writes: This galaxy is so distant that it would have been invisible without the gravitational lensing effects of a large galaxy cluster called Abell 1689, located ...
2
votes
0answers
85 views

Fourier Transform of Galaxy Images [closed]

I'm working on detecting optically overlapping galaxies for future astronomical surveys. I'm looking into feature extraction for HST images and have been computing the fourier transform of images in ...
-7
votes
1answer
272 views

Why are a few things in our universe named after chocolate? [closed]

Like the title says, why are a few things in our universe named after chocolate? For example, there are the Milky Way, galaxy and Mars. Is there a reason for this or not? Or is it that the ...
1
vote
2answers
221 views

Galaxy rotation curve and dark matter

I am reading "The Essential Cosmic Perspective" by Jeffrey O. Bennett, Megan O. Donahue, Nicholas Schneider, Mark Voit. In Chapter 14, it is stated that an evidence of the presence of dark matter in ...
2
votes
2answers
159 views

How do stars or galaxies get their spin?

It is my understanding that when a star, a planetary disk, or a galaxy forms, the rotational momentum of the whole system is conserved. Due to the smaller size of the resulting object, it will spin ...
5
votes
1answer
523 views

What is supposedly in the center of the Milky Way?

It's big. It's bright. It's white. It's so intense. But what is at the center of the Milky Way?
18
votes
8answers
5k views

Why can't we see distant galaxies with the naked eye?

If light keeps travelling in a straight line, why can't we see distant galaxies with the naked eye? Surely if you stared long enough, the light from them would eventually hit your eye? I apologize if ...
4
votes
1answer
184 views

Is there a strong galactic magnetic field?

My main question is: Is there a strong galactic magnetic field, perhaps driven by the supermassive black hole at the center of our galaxy? I am also wondering if this field would be strong enough to ...
10
votes
1answer
120 views

Does CIBER Experiment from Caltech suggest that there can be lots of stars which are not in any galaxy?

My question is about the implications of the observations recently made by the Cosmic Infrared Background Experiment, or CIBER, from Caltech. I've read at Caltech web site: "The total light ...
1
vote
1answer
80 views

What is the line of light in galaxy cluster MACS J1206?

I noticed this in a thread from world building, what is the continuous line of light in MACS J1206 slightly right of center in this picture? The only thing I could think of would be the side view of a ...
1
vote
2answers
147 views

What are the nearest galaxies I can observe?

What are the nearest galaxies I can observe using my Telescope? Does it require to be out of the city lights?
3
votes
3answers
195 views

What happens if you fail to reach escape velocity for the galaxy?

I was listening to Skeptics Guide to the Universe the other day, and Steve Novella mentioned that the escape velocity for the galaxy is 544 km/s. If an object fails to reach escape velocity on Earth, ...
2
votes
0answers
42 views

Synthesising types of galaxies using various stellar spectra

I have asked this on Physics Stack Exchange but Astronomy is probably more appropriate. I have been given the task of synthesising an elliptical galaxy, a starburst galaxy and a spiral galaxy ...
-1
votes
1answer
138 views

What will happen to our solar system if the milky way collided with Andromeda galaxy, would any planets survive? [duplicate]

Is there a chance if any planets in our solar system survive when the milky way and Andromeda collide?
12
votes
1answer
383 views

Do we get any benefit from being in a galaxy?

If our solar system were to somehow be created outside of a galaxy as a single star in the vast nothingness between galaxies, would life on Earth change any? Does being a member of a galaxy actually ...
2
votes
2answers
1k views

Diameter of any galaxy

I've been trying to figure out how to find the diameter in kpc of any galaxy given that one knows the distance to it in Mpc (d) and also the angular diameter/size (A) in arcsec. I had a formula before ...
0
votes
2answers
65 views

What happens if two galaxies collide very quickly?

What would happen if two galaxies collided very quickly (e.g. at near the speed of light)? Would they mostly just pass through eachother unscathed, or would there be very energetic collisions that ...
-2
votes
2answers
82 views

Brain vs galaxy [closed]

The number of neurons in the human brain is equated with the number of stars in the Milky Way. Could the Milky Way act as a consciousness of its own, with the gravitational strength between the stars ...
4
votes
2answers
328 views

Can we see individual stars in other galaxies?

Just wondering if we can examine individual stars from other galaxies, or if we are pretty much stuck with the billions that are in the Milky Way?
2
votes
1answer
69 views

Using Tully Fisher to measure Distance Problem

Can anyone explain by looking at the solution in the pic, how did the cos (i) came about? I guess they are getting this from the major-minor axis info in the question, but I am not sure about the ...
2
votes
1answer
585 views

What is the Fundamental plane for Elliptical Galaxies?

An alternate explanation rather than from wikipedia is preferable.
3
votes
3answers
267 views

Milky way: How do we know its appearance? [duplicate]

How can we know how does the Milky Way look like if we are in it? Sorry if the answer is evident, I am not an expert.
2
votes
4answers
170 views

Milky Way Formation

Is the Milky Way a collection of merged galaxies, or has it only been one galaxy that was created from the interstellar media?
12
votes
3answers
523 views

Questions about spiral galaxy arms

I have 2 questions related to spiral galaxies. Firstly, how did the arms form? Why would the stars accumulate into those specific areas? And secondly, why are they still intact? The inner parts of ...
5
votes
2answers
154 views

Fate of the Spiral Arms of the Milky Way and Andromeda

In a few billion years, the Milky Way and Andromeda will collide. Chances are, there won't be many spectacular stellar collisions, and there's a pretty good chance that the Solar system (and most ...
2
votes
1answer
121 views

What is the exact position of the Large Magellanic Cloud?

I am not able to visualize the position of the LMC and have not found a satisfactory explanation... Can someone please answer it this way? Relative to a ray joining the Earth to the ...
4
votes
3answers
1k views

What is the relative time difference between us and a star system in outer layer of our galaxy?

Just curious to know what will be the time difference between someone living on the outer layer of our galaxy and us, considering the known facts that Time is relative to gravity Our sun goes around ...
7
votes
1answer
147 views

Is there a paper on galaxy mergers in clusters of galaxies?

I'm looking for something to cite about galaxy mergers in clusters of galaxies. I need numbers on the frequency of mergers in the outer parts of galaxy clusters vs. the cluster center. In the center ...
2
votes
1answer
148 views

Which spiral arm of the Milky Way is Kepler-62 in?

I am trying to find out which spiral arm of the Milky Way the star Kepler-62 and its planetary system are in. All I can find by Google searching is that it is part of the Lyra constellation, but I ...
4
votes
5answers
418 views

Why aren't there galaxy-sized balls of iron out there?

Since we know that stars burn out, collapse, or blow up when too many of their atoms fuse inti iron, then how come, with all the ancient galaxies we've been observing, there isn't one galaxy whose ...
8
votes
3answers
596 views

Do we expect life to develop only in certain regions of the galaxy?

If I understand correctly, the Earth lies in an area of the galaxy - the "local bubble" - that is relatively free of dust and gases and where no new stars are being born. What is the current theory ...
8
votes
2answers
241 views

Is the Hubble Ultra-Deep Field image representative of the entire sky?

The Hubble ultra-deep field image is a photograph of an area of sky equivalent to a 1mm x 1mm piece of paper held a metre away from the eye (one thirteen millionth of the entire sky). It contains an ...
10
votes
3answers
804 views

Where does the Milky Way end?

I was reading this article and it says the following: Researchers measured the mass of the Milky Way and found that our galaxy is approximately half the weight of a neighbouring galaxy known as ...
2
votes
1answer
86 views

Sloan digital sky survey galaxies

I am trying to get some data from the Sloan digital sky survey (SDSS). This task turned out to be challenging for me as someone with only little knowledge about astronomy and maybe someone here can ...